Char t So ftware ManualChart
version 5.0
for Macintosh

e-corder®

www.eDAQ.com

This document was, as far as possible, accurate at
the time of printing. Changes may have been madeto the software and hardware it describes sincethen, though: eDAQ reserves the right to alterspecifications as required. Late-breaking information
may be supplied separately.

Document Number: UM-ES200M-1103
Copyright © November 2003
eDAQ Pty Ltd
6 Doig Avenue
Denistone East, NSW 2112
Australia

Trademarks of eDAQ

Web:www.eDAQ.com
E-mail:support@eDAQ.com

e-corder and PowerChrom are registered trademarksof eDAQ Pty Ltd. The names of specific recording
units, such as e-corder 201, are trademarks ofeDAQ Pty Ltd. EChem is a trademark of eDAQ Pty
Ltd. Chart and Scope are trademarks of ADInstruments
Pty Ltd used by eDAQ under license.

All rights reserved. No part of this document may be
reproduced by any means without the prior written
permission of eDAQ Pty Ltd.

Other Trademarks
Apple, Mac, and Macintosh are registeredtrademarks of Apple Computer, Inc.
Windows 2000 and Windows XP are either
registered trademarks or trademarks of Microsoft
Corporation.
All other trademarks are the properties of theirrespective owners.

ii

Chart Software

Contents
1 Getting Started 1
Learning to Use Chart 2
Where to Start 2
How to Use this Guide 2
Computer Requirements 3
The e-corder® System 3First Use 3
Basics of Data Acquisition 5
Sampling Rate 6Filtering 7
Digitization 9
Range 9Noise 10
Display and Expectations 11

2 Introduction to Chart 13
An Overview of Chart 14
Opening a Chart File 16
Closing a File or Quitting Chart 19
The Chart Window 19
The Tool Bar 24
Recording 25
Display While Recording 25
Blocks and Settings 26
Recording or Monitoring 27
Adding Comments While Recording 29
Background Recording 30
Performance 31

Chart Software

Interruptions 32
Recording Length 32

3 Setting Up Chart 35
Setting Sampling Rates 36
Maximum Sampling Rates 37
Slow and Fast Sampling Rates 37
Channel Controls 38
The Input Amplifier 41
Signal Display 41
Filtering 43
Signal Input Controls 44
Other Features 44
Zeroing Inputs 45
Units Conversion 46
Converting Quantities 47
Choosing Unit Names 50
Channel Settings 51
Triggering 55
Setting the Controls 56
Making Changes in the Chart Window 59
The Stimulator 60
Mode 61
Setting the Controls 62
The Stimulator Panel 65
Constant Output Voltage 66
The Stimulator Output 67

iii

4 Data Display 69

6 Data Analysis 129

The Chart Window 70
Time Format 70
Split Bar 71
Waveform Color 72
The Amplitude Axis 73
Changing Channel Size 75
Overlaying Channels 76
Display Settings 77
Channel Settings 81
The Overview Miniwindow 84
The Zoom Window 85
Displaying Digital Read-outs 89
DVM Settings 90
The DVM Log Window 92

Measuring from the Waveform 130
Using the Marker 131
Setting and Removing Baselines 132
Finding Data 133
Search Criteria 133
Selection Criteria 135
Repeatedly Finding Data 136
The Data Pad 136
Adding Data to the Data Pad 138
Setting Up the Columns 138
The X–Y Window 145
The Spectrum Window 147
Spectrum Settings 149
Data Pad Functions 152
Computed Input 153
Sampling Rates 154
Signal Displays 154
Raw Data Controls 155
Computed Input Controls 158
Computed Input Functions 159
Channel Calculations 167
Smoothing 171
Arithmetic 173
Cycle Variables 176
Differential 183
Integral 184

5 Working With Files 95
The Experiments Gallery 96
Using the Experiments Gallery 96
Managing the Experiments Gallery 97
Selecting Data 98
Deleting Data 100
Transferring Data 101
The Clipboard 103
Saving Options 104
Auto Save 108
Saving a Selection 109
Appending Files 110
Printing 111
Page Setup 111
The Print Command 113
The Notebook 115
Comments and Exclusions 117
The Comments & Exclusions Window 121
Using Exclusions 123
Finding Files 124
Backing Up Files 126

iv

7 Customizing & Automating
Chart 189
Preferences 190
External Trigger 190
Tool Bar 190
Cursor 192
Menus 192
Controls 194
License Manager 196
Chart Extensions 196
Memory Cache 198
Data Buffering 198
Startup 200
Special Access 201
Chart Software

Macros 202
Recording a Macro 203
Playing a Macro 204
Deleting a Macro 204
Options When Recording Macros 205
Macro Commands 209
Timed Events 222
Automatic Comments 226
Choosing a Connected e-corder 229
e-corder Startup 229
Choosing and Naming an e-corder 230

Index 267
Licensing & Warranty 277

A Menus & Shortcuts 233
Menus 233
Shortcuts and Tips 237

B Troubleshooting 243
Technical Support 243
Solutions to Common Problems 246

C Technical Notes 257
Calculation Details 257
The Spectrum Window FFT 257
Computations with Computed Input
Functions and Channel Calculations 261
Reference 262

D Experiments Gallery
Configuration Files 263
Sections 263
Key Lines 264
Comment Lines 264
Example 265

Contentsv

vi

Chart SoftwareC H A P T E R

O N E

1 Getting Started

Welcome to Chart software for Macintosh computers. Chart operates
as part of the e-corder system providing multichannel signal recording,display and analysis capability.

This chapter contains information on hardware requirements, and theuse of this guide in learning to use the application. There is also a basic
introduction to data acquisition.

Chart Software

1Learning to Use Chart
Where to Start
Before recording data read the booklet that came with your e-cordersystem and the e-corder Manual on the Installer CD. Be sure to connect
your e-corder to your computer properly.

How to Use this Guide
It is best to gradually work through this manual in front of yourcomputer. The information in the following chapters is set out in theorder you will probably require it.

Conventions
Menu commands and shortcuts are usually described using theconventions in Table 1–1. Note that shortcuts can appear in two forms:
hyphenated in text, and with a + sign in tables, to make each clearer incontext.
The screen shots used in this guide are from Mac OS 10.1. They weremade using the Mac OS X default appearance settings. There may bechanges in appearance when using Chart with later systems andsettings.

Table 1–1
Shorthand usages
referring to menu
commands and shortcuts.

2

Example phrase

Meaning

File > NewThe New command of the File menu

Chart > Preferences > Extensions…

The Extensions… command of the Preferences
submenu of the Chart menu

Channel Function pop-up > Input
Amplifier…

The Input Amplifier… command of the Channel
Function pop-up menu

Command-S, or
Command + S

Hold down the Command (apple, clover leaf)
key and type ‘s’Option-Shift-click, or
Option + Shift + click

Hold down the Option and Shift keys and click
the mouse button

Chart Software

Where to from Here?
This book is a reference guide for the main features of the Chart
software. Some specialist features are provided using Chart Extensions(software plug-ins) available from our web site, www.eDAQ.com.
Documentation for the Chart Extensions is also provided on the website.
Our documentation is continually being improved and updated, andlatest editions are available from www.eDAQ.com.

Computer Requirements• PowerPC or better• 128 MB RAM• 40 MB free hard disk space• 800 x 600, 256 color display or better• Mac OS X 10.1
• A CD-ROM drive• USB 2.0 or 1.1

The e-corder® System
The e-corder system is an integrated system of hardware and software
designed to record, display, and analyze experimental data. The
system consists of an e-corder recording unit and software programs(such as Chart and Scope) that run on the computer connected to thee-corder. Your e-corder unit has considerable computing power of its
own and performs many tasks that are necessary during data
recording. Once the e-corder transfers the data to the computer, thedata are available for display, manipulation, printing, storage andretrieval.

First Use
Ensure that the e-corder is connected properly to your computer (this iscovered in the manual that came with your e-corder) and turned on.

Chapter 1 — Getting Started3Click the Chart icon in the Dock or double-click the Chart icon in the
Finder.
The first time you run Chart, you will be presented with the dialog box
shown in Figure 1–1. Enter your name (minimum three characters),
organization (minimum three characters) and the license code that you
received with your copy of Chart. Click OK to enter the license, or Quit
to leave Chart.

Figure 1–1
The Chart License setup
dialog box.

Note that if the computer has an owner’s name in the system already(for file sharing), the name will be put into the Name box and selected
automatically. Just start typing if you want to overwrite it.
There may be a short delay while the program sets up the e-corder. If
the e-corder is not connected, then after naming your copy of theapplication, the dialog box in Figure 1–2 will appear. If this dialog box
appears when the e-corder is connected and turned on, see the manualthat came with your e-corder for help. Some of the information from thatguide on hardware startup problems is also repeated in Appendix B.

Figure 1–2
The dialog box thatappears if the e-corder is
not connected correctly.

4

Click here toaccess the
e-corder Startup
dialog box

Chart SoftwareQuitting Chart
If you want to quit Chart after naming your copy of the application,choose Chart > Quit. If you want to proceed with working through thisguide, just carry on.

Basics of Data Acquisition
The purpose of the e-corder system is to acquire, store, and analyze
data. Figure 1–3 summarizes the acquisition. Usually, the raw input
signal is in the form of an analog voltage whose amplitude varies
continuously over time. This voltage is monitored by the hardware,
which can modify it by amplification and filtering, processes called‘signal conditioning’. Signal conditioning may also include zeroing, forexample the removal of an unwanted steady offset voltage from atransducer’s output. After signal conditioning, the analog voltage issampled at regular intervals. The signal is then converted from analog
to digital form before transmission to the attached computer (computersneed digital data). The computer software usually displays the data
directly; it plots the sampled and digitized data points and reconstructs
the original waveform by drawing lines between the points. Digital
data can be stored on disk for later retrieval. Software can also easily
manipulate and analyze the data in a wide variety of ways.
Most of the parameters that affect acquisition can be set by the user
through the software. To make a good recording, the parameters must
be appropriate for the signals being recorded. In some disciplines you

Figure 1–3
A graphical summary ofdata acquisition using an
e-corder system.

Computere-corderTransducer…101101…
MechanicalsignalInput

Analog electricalsignalAmplification

Chapter 1 — Getting Started

Digital signal

Filtering

Sampling

Display5may be able to find tables of suggested sampling rates, ranges, andfilter settings, but these should not be applied blindly. You still need toknow the science (what you are recording, why you are recording it,
and what relation it bears to real phenomena) and the technique (howbest to record, and what limitations or compromises are inherent in theprocess).

Sampling Rate
Sampling replaces the original continuous analog signal by a series of
discrete values (samples) taken at regular time intervals. The
appropriate sampling rate depends on the signal to be measured. If thesampling rate is too low, information is irreversibly lost and the original
signal will not be represented correctly. If it is too high, there is no lossof information, but the excess data increases processing time andresults in unnecessarily large disk files.
Figure 1–4
Undersampling:
oscillating pressure
signal recorded at 20 /s(too slow) and 200 /s(correct sampling speed)

20 /s

200 /sRecordings of periodic waveforms that have been sampled too slowly
may be misleading as well as inaccurate because of aliasing. An
analogy to aliasing can be seen in old films: spoked wagon wheels
may appear to stop or even go backwards when their rate of rotation
matches the film frame speed — obviously not an accurate record.
To prevent aliasing, the sampling rate must be at least twice the rate of
the highest expected frequency of the incoming waveform. This
sampling rate is known as the Nyquist frequency, the minimum rate at
which digital sampling can accurately record an analog signal. For
example, if a signal has maximum frequency components of 100 Hz,

6Chart Softwarethe sampling rate needs to be at least 200 Hz to record it accurately.
To provide a safety factor to guard against information loss, it is usual
to sample at five to ten times the highest expected frequency rather thanthe minimum two times.
Actual signal (3.5 Hz), at 40/s

Figure 1–5
Aliasing: sampling a
3.5 Hz signal at 4 /s
gives a misleading
waveform, an apparent
signal of 0.5 Hz.

Aliased signal (0.5 Hz), at 4/s

Samplepoints at
4/s

In most cases, the highest expected frequency will be known. It may
well be limited by the transducer used: a bridge transducer to measuremechanical force will not produce high frequencies, for instance. If you
are unsure of the frequency range (bandwidth) of your signal, a usefulrule of thumb is to choose a sampling rate high enough to allow at least
5 to 20 samples for any transient peaks or recurring waves in thesignal.
The highest frequencies in a signal can be formally determined bysampling the signal at the maximum rate, and looking at the spectrumof the signal (using the Spectrum window). High-frequency components
in the spectrum with less than 2% or so of maximum amplitude usuallycontribute little to recording accuracy.

Filtering
Any analog waveform can be described mathematically as the sum of anumber of pure sine waves at various frequencies and amplitudes. Low
frequencies characterize the slowly changing parts of a waveform; highfrequencies, the quickly changing parts. A filter removes selected
frequencies from a signal: for instance, a low-pass filter lets low
frequencies pass and stops high frequencies. Low-pass filters arecommonly used to help reduce noise and give a smoother signal. A
high-pass filter removes any steady component of a signal; it also
removes slow fluctuations.
Chapter 1 — Getting Started

7

Figure 1–6
The effects of filtering ona mixed-frequency
signal: a high-pass filter
removes low frequencies;
a low-pass filter removes
high frequencies.

Original signal (highand low frequencies)

High-passfilter

Low-pass filter

Filtered signals

Filters are imperfect. A 200 Hz low-pass analog filter, say, might leave
frequencies up to 150 Hz untouched, reduce a 200 Hz signal to 0.7 of
its original amplitude (this is its cut-off frequency), and reduce higher
frequencies more and more. If you were expecting useful frequencies of
up to 100 Hz, you could sample at 400 samples per second and filter
out any higher frequencies using a 200 Hz filter. If higher frequencies
are left unfiltered, then they could possibly be aliased, resulting in theappearance of spurious lower frequencies.
Filtering can change the signal to some extent: its use must be balanced
against the distortions it can remove, such as noise, baseline drift, andaliasing. If the filter settings overlap the bandwidth of a signal, then thesignal will have components removed. If you were interested in a
waveform with components down to 5 Hz and used a 20 Hz high-passfilter (filtering out 0 to 20 Hz signals), then vital information would be
lost from the signal.

Figure 1–7
A signal with various
low-pass filter settings:
some filtering cleans up
noise, but too much
distorts the highfrequency spikes.

Unfiltered

Noise reduced

Over-filtered

8

Chart SoftwareFiltering can also be applied to the recorded digital data after
acquisition. Chart has a smoothing channel calculation available tohelp remove noise, clutter, and unwanted high frequencies from signals.
This acts as a simple low-pass filter by averaging adjacent data points,
but shouldn’t be used as a substitute for the correct low-pass filter
during recording. It is most useful in helping clean up signals recorded
at high sampling rates.

Digitization
When analog data such as voltage amplitude is converted to digitalform for use by a computer, it must conform to a fixed number of values(for instance, a digital thermometer might only measure temperature to
the nearest degree). Any analog values between these values arerounded up or down. The approximation is usually very good, since thenumber of values is very large. The analog-to-digital converters (ADCs)
that perform the digitization usually generate a number of values equal
to a power of two: an ADC with 12-bit resolution can resolve a signal
into 212 or 4096 possible amplitude values, which is adequate for most
biological signals; an ADC with 16-bit resolution can resolve a signal
into 216 or 65 536 possible amplitude values.
e-corder units use 16-bit ADCs. Chart fits 64 000 of the 65 536
possible values to the range, allowing some leeway above and below
for a small amount of overrange. Thus the 10 V range would be
divided into 64 000 fixed values from –10 V to +10 V; the minimumchange in voltage that could be discerned at that range would be
0.3125 mV. At 10 mV range, the minimum discernible voltage change
would be 0.3125 µV. ADC resolution is part of the hardware, andcannot be set by the user.

Range
Range is inversely proportional to gain, the amount of amplification,and is a more useful concept than gain since it relates directly to thesignal being measured. The range can be set independently for each
input on an e-corder recording unit.
If the signal amplitude exceeds the range, there will be severe loss of
information. (This is the same as ‘clipping’ in a stereo system wheremusic is severely distorted when the amplitude exceeds the capabilities

Chapter 1 — Getting Started

9

of the amplifier.) Any signal exceeding the range is ‘out of range’, acondition indicated where no amplitude can be given. If there is any
possibility of this condition occurring, you should set the range to alarger value.
For the best resolution, the maximum amplitude of the signal you areinterested in should be reasonably close to the chosen range without
exceeding it. That way, the minimum change in voltage discernible indigitization remains small in relation to the signal being measured (thesignal is digitized after it is amplified). If a signal is very small in
relation to the range, then its resolution will be degraded. In extreme
cases, the recorded waveform may appear stepped rather than smooth.
Even though you could see a ±380 mV signal easily enough at thedefault 10 V range, you would use the 500 mV range to measure it at
maximum resolution. It would be safer in practice to use a 1 V or 2 V
range, though, since unexpectedly large peaks could exceed the 500
mV range if the signal was not well-behaved.
Changing the display of the waveform on screen (by enlarging it in theZoom window or by stretching or shrinking its Amplitude axis, forinstance) does not affect its resolution, just its appearance.

Noise
Noise is defined as ‘unwanted signal’. It is likely to be a problem atlower range settings, when you are trying to measure very small
signals. Random noise, such as thermal noise, is inherent in allelectronic circuits, including those of the e-corder recording unit, andgenerally must be filtered to minimize it. The trick is to choose a lowpass filter setting that removes most of the background noise without
unduly changing the signal of interest.
For biological signals, differential inputs are preferred, and can reduce
common-mode noise due to ground loops. (Ground loops occur wheremultiple connected pieces of recording equipment are connected to

Figure 1–8
Noise in a signal (left)
can mar the original
signal (right), unlessfiltered out.

10

Chart Softwaremains power grounds.) e-corder single-sided inputs are ‘quasidifferential’, and automatically neutralize up to a fraction of a volt ofground loop noise, the most that normally appears.
Other important causes of noise are stray electromagnetic andelectrostatic fields, and include interference (often at the mains
frequency of 50 Hz or 60 Hz) from unshielded power lines, switchingequipment, fluorescent tubes, transformers, computers, network cables,
VDUs, and so on. The interference can interact significantly with arecorded signal. Reasonable care in the arrangement and shielding ofequipment and cables will reduce such interference. Particularly
delicate measurements, however, may require special apparatus and acontrolled environment.

Display and Expectations
The two most important settings for data recording are the input range
and recording speed. Provided these are set correctly, then your signals
will be recorded which high precision. However, the actual
appearance of the data on the computer monitor can be affected by thevertical magnification and time base compression used in the Chart
display settings, and screen resolution of your monitor.
The screen display on a monitor is generally about 72 dots per inch(dpi), so the apparent resolution may be poor if the display is kept
small. However, the resolution of the underlying recorded data is
independent of the resolution of the display: even if the channel is verythin or not visible on screen, sampled data are recorded at full fidelity,
as can be seen by expanding the channel display or examining thesignal in the Zoom window.
High-resolution printing will also show data more accurately.
It is important to check display settings and axis labels carefully when
examining a signal.

Chapter 1 — Getting Started

11

Figure 1–9
An signal shows withvarious display settings.

12

Chart SoftwareC H A P T E R

T W O

2 Introduction to Chart
Chart is one of the application programs that together with youre-corder make up the e-corder system, a powerful data acquisition
system driven from an intuitive and robust interface.

This chapter provides a general overview of Chart, looks at the Chart
window in detail, and deals with the basics of recording data in Chart.

Chart Software

13

An Overview of Chart
Chart, together with the e-corder hardware and a Macintosh computer,gives you the capabilities of a multi-channel chart recorder and more.
Depending on your hardware, you can record on as many as sixteen
channels at various rates. Chart also provides a range of powerful andeasy-to-use features that transcend the limitations of a mechanical penand-ink recorder.

Controls and Display
Controls are easy and intuitive. The Chart window can be resized likeother Macintosh windows. The data display area can be compressedor expanded horizontally, or split into two panes, and the vertical sizeof each channel can be changed to suit, simply by dragging thedividing bars. Channels can be turned off or hidden if they are notrequired, or overlaid to compare waveforms directly, and their
Amplitude axes can be dragged, stretched, scaled, or set through a
dialog box for optimum data display.
Range and filtering options, and even sampling rate, can be set
independently for each channel. You can type in appropriate channel
titles and define units of measurement for each channel. Display colors,
patterns, and grids can be altered. A Tool bar allows common
operations and user-defined macros to be performed with a single clickof the mouse.

Recording
You can not only view data as they are sampled, but also review pastdata while sampling, in a split or single window. Sampling rate andrange can be changed while recording at lower sampling rates. You
can start and stop sampling at any time and build up a Chart file withmany individual sections of data. Recording is usually to disk, and data
recorded this way can survive a power failure or system crash — whichis especially useful if you are making lengthy recordings. (You have theoption of recording to RAM if your disk drive is slow.) Comments tomark points or areas of interest can be made during or after recording,on all or on specific channels. A Notebook accessory is available formaking general notes about a recorded data file.

14

Chart Software

Saving, Printing, and Editing
Chart recordings can be printed, edited, and saved to disk for later
review. You can save the settings of any Chart file to enable anexperiment to be repeated quickly and easily, without having to go
through the process of setting it up again. You can print a selection orsave it as a file — this allows for easy editing by extracting only thatpart of the recording you need. You can append files to the end of anopen file, to produce recording summaries conveniently in a single file.
Data can be transferred as text to other Macintosh applications, such as
spreadsheets or statistics programs.

Analysis
When you have finished recording, you can scroll through your data
and make measurements directly from the recording — since everythingis digital, you are given a direct read-out, with no chance ofmeasurement errors. You can measure relative to a reference point set
using the Marker, or set a baseline to remove an unwanted offset. You
can search any channels for comments, peaks and troughs in the
waveform, block boundaries, and so on, and select data according tocriteria you specify. The Data Pad calculates and stores statistics about
recorded data, and can be printed out or have its data transferred toother applications. The X–Y window gives you a plot of data from one
channel against another. Chart has an Overview miniwindow forfinding areas of interest in large recordings, and a Zoom window for
examining a section of the recording in more detail in which you canoverlay channels (independently of any overlaying in the Chart
window). Exclusions let you mark points and areas to be excluded fromdata searches and so on. Comments and exclusions in a file are listed
in the Comments & Exclusions window, from which you can go directly
to the part of the record where they were added.

Advanced Features
Triggering functions let you control when Chart starts and stops
recording, using internal or external measurements. The Stimulator
allows you to set up an external stimulus for an experiment, and theStimulator Panel control allows this to be turned on or off or adjusted as
required during recording. A range of computed input functions can beapplied in real time to measured data: event counting, signal

Chapter 2 — Introduction to Chart

15

frequency, and so on, cyclic and envelope parameters, and differential
and various integral functions are all available. Computed data can bedisplayed in place of the raw data or in addition, on another channel.
Data can be smoothed by channel calculations to remove unwanted
high frequencies in the waveform.

Customizing and Automating
Chart can be extensively customized for your purposes. Controls, andmenus and their commands (and keyboard shortcuts) can be locked,
hidden, or altered, and Chart as a whole simplified, say, for student
use. Chart files and related files such as documentation and multimedia
files can be added to the ‘Experiments Gallery’ for easy access. Macros
can be created to speed up and to automate complex tasks, stored inany menu in a file, and added to the Tool Bar as buttons. Chart
extensions are available to add specialist analysis capability to Chart,
and to provide data export options to other applications. For example,
physiological signal peaks can be analyzed using Peak Parameters,and Export QuickTime allows you to play your recorded data in amovie on a web site or in a presentation.
The Timed Events dialog box allows you to create a list of actions you
want performed at particular times: Chart will do the rest. By setting up
the digital output lines appropriately (only available on speciallyconfigured e-corder units), you can control their states while recording,to turn external devices on and off, control pumps, relays, indicatorlights, and so on. By setting up a list of comments that correspond tostates of the e-corder digital inputs, the external trigger or stimulator, orvarious Function keys, you can have Chart automatically insert
appropriate comments while recording when the digital inputs change,a Function key is pressed, and so on.

Opening a Chart File
It is a good idea to have a Chart file open if you are working throughthis guide, so that you can try the commands, controls, and settings as
they are discussed in the text. First, make sure that the e-corder isproperly connected to your computer, and is turned on. You may wish
to learn Chart without the e-corder — if you have taken home a copy
on your laptop, for instance. In this case, on opening a file, a dialog
box will offer the Analysis option, which lets you use Chart except

16

Chart Software

Figure 2–1
Chart desktop icons:
double-click one to open
Chart.

▼ Refer
The Experiments Gallery,
p. 96

where it requires the e-corder hardware, such as for recording.
Unusable controls appear dimmed.
To open a Chart file, click one of the Chart icons in the Finder to selectit, and choose File > Open…, or simply double-click the icon. Theremay be a short delay while Chart sets up the e-corder. The top icon in
Figure 2–1 shows the Chart application, which if double-clicked will
open a new untitled file with the current start-up settings. The middle
icon shows a file of recorded data, which opens up a saved Chart data
file. The bottom icon shows a a settings file, which will open an untitledfile set up in a predefined way.
In each case, Chart opens and the Chart window will appear. By
default, the window of a new untitled file opened when Chart starts up
will fill the screen, but its size can be adjusted. If you start Chart without
a file and the Experiments Gallery has been set up, the Experiments
Gallery dialog box will appear at this point: close the dialog box andignore it for now; its use is described in Chapter 5.
Once the Chart application is open, you can open an existing file orcreate a new one. Choose File > New to create a new, untitled Chart
data file. If you choose File > Open…, the Open dialog box appears(Figure 2–2).
At the top of the dialog box, the Show pop-up menu lets you choose
which type of files are displayed. All Chart Documents displays data

Figure 2–2
The Open dialog box(see the Macintosh
system help for the many
shortcuts available).
Note
Hold down theCommand key as you
start up Chart to bypass
the current start-up
settings and use thedefault settings. Release
the key when the alert
box appears, and click
the Yes button.

Choose a file
type here
This pop-up
menu shows
the folder or
disk location
Choose a file
here

Turn this on toclear oldmacros on
opening a file

Chapter 2 — Introduction to Chart

Click here
to open theselected file17

and settings files, or you can choose to display one or other of thesetypes individually. Choosing Chart (Win) Data displays Chart for
Windows data files. Other choices may be added through Chart
extensions.
If the Discard Existing Macros checkbox is on, it prevents macros
accumulating as you open files (this is discussed in a later chapter).
The information in a Chart data file is made up of data and settings.
Data are the recorded waveforms. Settings are of two sorts: those that
affect recording, such as the sampling rate, channel ranges, triggering,and stimulation functions; and those that affect the way the data looks,
such as the window size, channel areas, and display settings (alongwith menu arrangements and macros). A data file opens with thesettings it had when it was saved. Chart lets you have only one data
file open at a time, so if you open another, your old file must be closed.
If it has any unsaved changes, an alert box informs you and lets you
save or discard them, or cancel. If you create a new file, the new filecontinues to use the settings from the file just closed.
Opening a settings file, if no Chart file is open, creates a new untitleddata file with the defined settings. If an existing Chart data file is open,
then an alert box gives you the choice of creating a new untitled data
file with those settings, or applying the settings to the current Chart file.
Applying settings to a file affects the display of existing data and therecording settings for subsequent sampling. It does not affect therecording settings of, or alter, existing data: sampling rates, ranges,
applied units, and so on are all left unchanged.

Opening a Chart for Windows File
Chart for Macintosh can import files written by Chart for Windows. To
show Windows formatted Chart data files, choose Chart (Win) Data in
the Show pop-up menu. If one is chosen and the Open button clicked, a
new untitled file will be opened containing the Windows data. The
data and channel titles are imported. The settings for range, computed
input, and units conversion are not imported and will need to be
redefined if they are required for new data. Channel calculations are
ignored (only recorded data is imported). Most display settings, such asdata trace colors, channel heights, and so on, are ignored. The Data
Pad and Macros are also ignored.

18

Chart SoftwareClosing a File or Quitting Chart▼ Refer
The Experiments Gallery,p. 96

To close a Chart file, choose File > Close. To quit Chart, choose Chart> Quit. In either case, if you have made any changes, an alert box willappear, asking you if you wish to save your work. Click the Save
button if you want to keep the changes you have made; click the Don’t
Save button to discard them. Note that when you close a Chart file, theExperiments Gallery dialog box (see Chapter 5) will appear (provided
that it has been set up).

The Chart Window
All essential controls for recording data are provided within the Chart
window, illustrated in Figure 2–3. These controls are discussed briefly
below, and, in most cases, in more detail elsewhere. There are threemain areas in the window, from left to right: the Amplitude axis area,
which contains the scale for each channel; the data display area,
which contains recorded data; and the channel control area.
The Menu bar at the top of the screen contains the Chart menus (seeAppendix A), allowing you to set up and modify the way Chart looks
and behaves. Window > Chart Window returns to the Chart window
from another, or creates a new, untitled Chart data file. The Tool bar
appears by default between the Menu and Title bar of the Chart
window, and provides shortcuts for common tasks, including returning
to the Chart window or opening a new file.

Navigating
The Scroll bar lets you move through the file’s data in the Chart
window. The box in the Scroll bar shows where the display area is inrelation to the file as a whole. Click the left or right arrows, or drag thebox, to move smoothly left or right. Click in the gray region to eitherside of the box in the scroll bar to jump a screen left or right. You canalso move left or right by pressing, respectively, the left and right arrow
keys on the keyboard. Hold down the Option key while pressing the leftor right arrow key to jump a block left or right (the block boundary will
be moved to the left edge of the Chart window). Hold down theCommand key while pressing the left or right arrow key to go to thebeginning or the end of the file.

Chapter 2 — Introduction to Chart

19

Figure 2–3
The Chart window.

Time & Date button

Block button

The Rate pop-up menu lets you
choose how fast Chart samples data
Rate/TimedisplayDatadisplaybar

Set channel
range — thebutton isdimmed if thechannel is off

Amplitude
axis
Scale
pop-upmenu

Set the channel
function< The data display area

Scaling
buttons

Set the signal
trace color

Range/
Amplitude
display

Re-sisechanneldisplay bydragging
the channel
separator

Click here for achannel status
pop-up list
< Time axis >Marker

Memoryremaining

Split
bar

Scrollbar

Pause/resume
scrolling whilesampling

Start /stopsampling

Compress or reexpand the record
horizontally

Pause/resume recording
while still sampling

You can manually scroll data by holding down the Option key while
the pointer is over the data display area: this turns the pointer into ahand that can drag the data back and forth. If you ‘push’ the data, bymoving the hand and releasing the mouse button while it is moving, thefile keeps scrolling through automatically at the speed at which you
moved it. It will stop at the beginning or end of the file, or when you
click anywhere in the Chart window.
You can go directly to a block of data by clicking its numbered Blockbutton. Clicking and holding the mouse down over the button pops up
a menu letting you choose to go to the block or to select it.
20

Chart SoftwareView Buttons
The View buttons allow you to compress or re-expand the horizontal
scaling of a file in the Chart window (the steps are 1, 2, 5, 10… up to2000 to 1). To see more of the file on screen at once, click the left (farmountains) button to compress it. To expand the file out again, click theright (near mountains) button. The pop-up menu between the two shows
the current compression and lets you choose the extent of horizontal
compression directly. If you print a horizontally compressed file orselection, then it will print at the compression at which you see it on
screen.

The Chart Axes
The horizontal Time axis, above the Scroll bar along the bottom of theChart window, records the time from the start of sampling or theabsolute time in various formats, depending on the time display mode
(which can be set using the Display Settings dialog box).

▼ ReferUnits Conversion, p. 46

For each channel, the vertical Amplitude axis on the left of the window
indicates the amplitude of the recorded waveform. Note that the axis
area remains blank until some data are actually recorded. The scale foreach channel is initially set by the range control on the right side of thewindow, but can be stretched or dragged using the pointer. Display
options can be chosen from the Scale pop-up menu, including whichchannel of an overlaid set is active. The data trace color, title, and unitsof the active channel are shown in the axis. Units are volts by default,
but may be changed to any other units (for example mmHg, Ω, or kPa),by using units conversion.

Scaling Buttons
The Scaling buttons are at the bottom left of each channel’s Amplitude
axis. Click the up button to enlarge or down button to reduce thevertical scale, halving or doubling what is shown each time.

Channel Controls
The channel controls are located rightmost in the Chart window, at theright of the data display area.

Chapter 2 — Introduction to Chart

21

The Rate pop-up menu at the top right of the Chart window controls the
sampling rate, which is usually the same for all channels (but can be set
independently for each channel).
There are three individual channel controls for each channel. Click the
button to the left to choose the range from the Range pop-up menu.
Click the channel title or the button at its right to choose options fromthe Channel Function pop-up menu. Click the colored box to choose thechannel’s data trace color from the Color pop-up menu. The channel’s
Range pop-up menu button is dimmed and unusable when the channel
is off.
Range
pop-upmenu

Color
pop-upmenu

ChannelFunction
pop-upmenu

Sampling Parameter Display
The Rate/Time display shows the current set rate of sampling (thesampling rate in samples per second and the scrolling speed in seconds
per division) if the pointer is over the channel control or Amplitude axis
areas, or the time at the pointer position over the data display or Timeaxis areas. If channels are set up to record at different rates, then the
Rate/Time display shows the maximum. The Range/Amplitude display
shows the current range of each channel if the pointer is over thechannel control or Amplitude axis areas, or the amplitude of the
waveform at the pointer position over the data display or Time axis
areas.
The Channel Status indicator is a diamond at the right of the channel
control area for each channel. It is solid if the channel is on, open if thechannel is off, and contains an = sign if a channel calculation isapplied. Clicking the indicator pops up a list showing the sampling
rate, range, what is to be recorded (raw data or a computed function,and from which input), the eDAQ Amp or Pod settings and filter
settings, and any active channel calculation.

Data Display Area
Recorded data are shown in the area of the Chart window bounded by
the channel control area on the right and the channel Amplitude axeson the left. The data for each channel are to the left of the channel title
and bounded above and below by horizontal bars. These bars, orchannel separators, can be dragged up or down to vary the size of thechannel display areas (double-click them to restore their original

22

Chart Softwarepositions). The separators can also be removed, to overlay adjacentchannels.

Split Bar

Split bar

The vertical Split bar, at the left of the data display area, can be
dragged to the right to split the data display area into two parts, eachwith its own scroll bar and View buttons (if there is room), so that you
can compare different sections of recorded data, or compare data
already recorded with new data as they are sampled.

Memory Indicator
A box at the bottom left of the Chart window gives a numeric indicationof current memory available for recording (disk or RAM), in gigabytes,
megabytes, or kilobytes. If the remaining memory becomes very low,the box is highlighted.

The Marker
The Marker can be found in a box at the bottom left of the Chart
window, above the memory indicator box. It can be dragged from its
lair onto the data display area to set a particular data point on a
waveform as a zero reference point, so that measurements can bemade relative to that point. Double-click it or click its box to send it
home. During sampling, the Marker temporarily disappears, and its
box shows roughly how much of the computer’s processing power isused during the operation.

Start Button
To start sampling, click the Start button at the bottom right of the Chart
window. The Start button is also available to the right of the Tool bar.
The button then changes to Stop: click it to stop sampling. The button
may show a dimmed Wait… while starting or stopping if the e-corder
or computer is particularly busy.

Record/Monitor Button
The Record/Monitor button at the bottom right of the Chart window, tothe left of the Start button, controls whether data are recorded as they
Chapter 2 — Introduction to Chart

23

are sampled (the default) or merely displayed, and discarded whensampling stops. When monitoring (to get an idea of incoming signal
characteristics, perhaps), a cross is shown. Click the button to switch
between recording and monitoring.

Scroll/Review Button
The Scroll/Review button at the bottom right of the Chart window, tothe left of the View buttons, controls whether data are scrolled while
recording (the normal behaviour), or whether you can instead use thescroll bar to review the recorded data even during recording. Depress
the button for the review option.

Time & Date
Click the Time & Date button, the clock at the top right of the Chart
window, to open a dialog box letting you set the time scale format, andwhether to display the date and time data at the cursor position wererecorded.

Pointer
The pointer will change form as you move it about the Chart window,
giving you an indication of its function in certain areas — it becomesan I-beam over a text entry area, for instance. It becomes dimmed
when it cannot do something under particular conditions.

The Tool Bar
The Tool bar provides shortcuts for common tasks in Chart in the form of
buttons. The default buttons are shown in Figure 2–4: you can change it
to suit your preferences, and add new buttons for any available
macros. You can assign Function keys to the buttons for use with anextended keyboard. The Tool bar can be hidden if you don’t want to
use it, or moved by Shift-dragging it.

Figure 2–4
The Tool bar.

24

Chart Software

The text box at the right of the Tool bar tells you the function of the
button that the pointer is over. It will also indicate the state of Chart insome cases: loading data or settings, saving, sampling, recording amacro, and so on.

Recording
To start recording, click the Start button at the bottom right of the Chart
window or to the right of the Tool bar. The button then changes to Stop:
click it when you want to stop recording. The button may show adimmed Wait… while starting or stopping if the e-corder or computer isvery busy. Chart uses the visual metaphor of a mechanical chart
recorder: recorded data scroll across the data display area from theright of the window as if the display area were a roll of paper in such a
device, with new data being drawn at the right and old data moving
left.
When recording, the controls at the bottom of the Chart windowchange, as shown in Figure 2–5. The Time axis area goes gray, andthe Recording Status indicator appears; and the scroll bar is replacedby the comments bar. The Marker is replaced by an indicator showing
roughly how much of the computer’s processing power is used during
sampling. The controls are discussed in detail later on.

Figure 2–5
Control changes during
recording.

CPU load indicator

Channel the comment
applies to (* for all)Comment
number box

Recording Status indicator

You can add yourcomment text here

Display While Recording
While recording, the amplitude of the signal being recorded is shownin the Range/Amplitude display at the right of each channel, unlesssampling at higher rates. If units conversion is being used, the value isdisplayed in the set units rather than as a voltage. The time is also
Chapter 2 — Introduction to Chart

25

Figure 2–6
Displays of the time andamplitude while
recording.

shown in the Rate/Time display at the top of the channel control area,
in a form depending on the time display mode (usually from the start ofthe block). These displays are updated every second or so.
Chart records to disk by default, or memory (RAM) if data buffering isturned off, and sampling stops automatically when disk space ormemory runs out. The space left in which to record is monitored. A
small box at the bottom left of the Chart window gives a numericindication of current remaining space, in gigabytes, megabytes, orkilobytes. If the remaining memory becomes very low, the box ishighlighted.

Blocks and Settings▼ Refer
Display, p. 78

A solid vertical line is drawn between two sections (user-defined‘blocks’) of recorded data to indicate discontinuity, for instance if you
stop recording and then start again. If you change the range of one ormore channels, a new scale is drawn between the two blocks for eachchanged channel to show the new range. Blocks always apply acrossall channels, even if only one has been changed. Block numbers areshown at the start of blocks as white-on-black tags in the Time axis.
Block numbers, lines, and scales can be hidden if this is desired.
At slower rates, you can change the sampling rate and channel range
settings without having to stop and restart recording. Chart will simply
start a new block at the point where the settings were changed,
drawing a solid vertical line or a new scale as appropriate. The display
will momentarily stop scrolling while you are making settings changes,
then update once the operation is complete.
A numbered Block button appears for each block as it is recorded. The
width of the button is proportional to the number of samples in theblock. You can go directly to a block by clicking its Block button;pressing the button pops up a menu letting you choose to go to theblock or to select it. In any case, the start of the block is shown (theblock boundary is moved to the left edge of the Chart window) if it is
not already visible, and a brief animation shows the block’s position.
Under the title bar there is a thin black strip, the Data display bar, used
to indicate where the data display area is in relation to the blocks. The
bar is positioned over the buttons for the block or blocks visible in thedata display area, and its length is in proportion to the extent of theblock or blocks shown.

26

Chart Software

Data display bar

Block buttons

Figure 2–7
User-defined blocks of
data: left break, after
stopping and starting;right, after changing achannel’s range.

Block boundary

Scrolling buttons

Block number

If there are too many Block buttons to show along the top of thewindow, then left and right arrow buttons appear at either side: click
them to scroll one Block button left or right — this doesn’t change
anything except the range of Block buttons that you can see.

Quick Block Information
Often, you want to get information about a recorded block. This can beobtained from the Data Pad easily enough, but for a quick check, justclick and hold down the mouse in the data display area for a channel.
This highlights the visible area of the block with a heavy border, andpops up a list (Figure 2–8) showing the sampling rate, range, any
active units conversion or channel calculation, the block number, andthe date and time at which the block recording started. (This is similar
to the information available from the Channel Status pop-up list, but
applies to existing data rather than the data to be recorded.)

Recording or Monitoring
The Record/Monitor button at the bottom right of the Chart window, tothe left of the Start button, controls whether sampled data are recorded(the default) or merely displayed on the screen, perhaps to get an ideaof incoming signal characteristics. When monitoring, sampled data canbe seen coming in, but the data are not actually recorded, andChapter 2 — Introduction to Chart27

Figure 2–8
Block Information pop-up
list.

Figure 2–9
Record/Monitor button:
left, data displayed andrecorded; right, data
displayed but notrecorded.

disappear once sampling stops. Clicking the button switches between
recording and monitoring. The data display area is grayed while
monitoring, so it is easy to distinguish monitoring from recording. The
grayed area disappears (along with any sampled data in that area)
once monitoring stops. The button is inactive (and dimmed) when
triggering is in operation. You cannot add comments while monitoring,
since there is no real record, so the box in the comments bar isdimmed, and typing has no effect.
You can stop or start recording data while sampling normally byclicking the Record/Monitor button. This is useful to see if incoming
signals are behaving themselves before you actually record them. If
fixed-duration recording is set up and Chart is monitoring rather thanrecording, then when you click the Record/Monitor button, Chart
records for the set time and then goes back to monitoring.

Recording Status Indicator
Figure 2–10
Recording Statusindicator display.

While sampling, a shadow box appears just to the left of the Start
button, giving information on the recording status of Chart (see Figure2–10): whether data are actually being recorded, or whether Chart is
waiting for a trigger or for the post-trigger delay time to elapse. This
gives you a quick visual indication of recording status.
‘Recording’ means that data are being recorded to memory (either todisk, the default, or to memory). The waveform icon at the right end of
the box ripples when Chart is recording. If data are not being recorded
and are only being displayed on the screen, ‘Not Recording’ shows.
The waveform icon flashes to give a visual cue. If triggering is set up,‘Waiting for trigger’ shows while the e-corder is waiting for a trigger
event to occur before it starts sampling. If there is a trigger delay, ‘Post-

28

Chart Software

trigger delay’ shows after triggering, while the e-corder is waiting forthe delay to elapse. If the internal timer is set up, ‘Int. Timer’ shows
while the timer is counting down prior to recording a block of data. A
few other messages appear in some circumstances, for instance, if an
operation takes a while to suspend.

Adding Comments While Recording
During recording, comments can be entered as required, and areautomatically numbered as they appear. Type what you want to say: it
appears in the text entry area at the bottom of the Chart window (seeFigure 2–5). Pressing the Enter or Return key adds the comment to thefile at the time the key is pressed. By default, the comment applies for
all channels, and the numbered comment box is preceded by anasterisk. To comment on a specific channel, select the asterisk byclicking it or pressing the Tab key, and type the number of the channel,
or click the channel in the data display area: the channel number
appears (for Channels 1 to 8; you can’t make a specific comment for 9
to 16 while recording). To apply a comment to all channels, select thecomment channel number and type a character other than 1 to 8, or
click the gray area at the bottom of the Chart window (the Time axis
when not sampling).

▼ Refer
Comments andExclusions, p. 117
Display, p. 78

Comments are stored and saved along with recorded data. Comments
are marked by numbered boxes in the appropriate channel on therecord, or along the Time axis, and a dotted vertical line. Comment text
may be visible in the window, or you can read the text in full byplacing the pointer over the comment box and pressing the mousebutton. Comments can also be added after recording, by choosing
Commands > Add Comment…, and can be read, edited, deleted,found, and printed from the Comments & Exclusions window. Commentboxes, lines, and text can be hidden if this is desired.

Figure 2–11
General and channelspecific comments, andthe pop-up comment box.

Chapter 2 — Introduction to Chart

29

Background Recording
You can do other things while recording in Chart. You can review
recorded data, compare old data with new by using the split-screenfeature, or even leave Chart recording in the background while you runother applications. This is useful for longer recordings, since thecomputer is not tied up doing one thing. You do need to be using Chart
at slower or moderate sampling rates, though, in most cases.

Recording While Reviewing Data
Normally, when recording in Chart, the recorded data scroll across thedata display area from the right of the window, with new data being
drawn at the right and the old data moving left. In these circumstances,
the scroll bar is dimmed and inactive, and the Scroll/Review button is
set to Scroll. When the button is clicked, it highlights and depresses,
and reviewing becomes active. The controls at the bottom of the Chart
window also change: the Time axis and scroll bar appear, but the
Recording Status indicator is still evident, showing that you are stillrecording.

Figure 2–12
Time axis control
changes when reviewing
while recording.

You can scroll through data already

Scroll/Review button set to

When reviewing while recording, you can use the scroll bar to scroll
through previously recorded data: the scrolling controls and keyboard
shortcuts all work normally. You cannot add comments using theComments bar while reviewing, but you can use Commands > Add
Comment… instead. Data are still being recorded, but the new data
are only visible if you scroll to the right-hand end of the record. At
faster recording rates, Chart may disable the review feature, since it
requires more computing power than normal.

Recording With a Split Data Display
Split bar

30

You can split the data display area before or during recording, by
dragging the vertical Split bar to the right. Splitting the data display
area allows the incoming data to be viewed alongside previously
recorded data, so that you can compare the two. Chart records
normally in the right-hand pane, so you can use the Comments bar toChart Softwarecomment on newly acquired data there, and so on, and can scroll
through the left-hand pane to check waveforms of interest. You can also
use the split-display feature while reviewing is active, to give two
independent scrolling views of the data while Chart is still recording.

Running Other Applications While Recording
You can run other applications while Chart is recording in the
background. You will need enough memory (RAM) in your computer tobe able to run multiple applications, of course. How slowly your otherapplications run while background recording is going on depends on
the sampling rate (in general, a slower rate would be needed), as wellas the type of computer you have. It helps if you have a fast computer:the faster your computer, the faster it can handle data from thee-corder, and therefore, the more time it can give to anotherapplication.

Performance▼ Refer
Setting Sampling Rates,
p. 36

CPU load indicator

To get the maximum performance from your e-corder, you should havea fast computer. At the root of most problems are low processing
power, memory, and hard disk speed. Slower computers not only limit
sampling rates, but also limit the rates at which you can make changes
while recording. If too much data are coming in for the computer tocope with comfortably, then changing ranges, bringing up dialog
boxes, and so on may stop recording.
To estimate how much of your computer’s processing power is used,
look at the CPU load indicator that appears in the Marker box during
sampling. Although this indicator is at best approximate, anything
greater than 50% indicates the system is under strain.
Chart estimates computer performance when it starts up and when it
first starts sampling data. If the estimate is too high and the computercan no longer cope with the amount of data being collected, Chart
stops recording and notifies you of the problem. This may occur if theamount of incoming data increases markedly, or after a while whenrecording very large files to disk, since the speed of writing to disk
decreases as the disk becomes fragmented. Fragmentation means thatdata are written in small blocks all over the disk rather than as one
contiguous file. This happens when a disk is nearly full, for instance, sothat data must be written to leftover spaces. (As a rule of thumb, hard

Chapter 2 — Introduction to Chart31

disks should always have at least 10% free space, and should bechecked regularly for file fragmentation with disk-checking software.)▼ Refer
Data Buffering, p. 198
Sampling Rates, p. 154

It is advisable to test the system before critical recordings using thesampling rates at which you intend to record, especially for extended
fast sampling. Recording to disk (page 34) is recommended as it will
give good performance on most computers, and in the event of apower failure or system crash, you will not lose your data. Recording to
RAM (page 33) may give better performance on slower computers, but
only if the amount of data being collected is less than the amount of
RAM: otherwise virtual memory will be used, requiring a fast hard disk
and processor.
Background activities decrease the ability of the computer to cope withthe data it gets from the e-corder. To avoid data loss at high sampling
rates, it is best if Chart is the only application running. You may also
want to turn off sharing services (in the Mac OS X System Preferences)such as file sharing, and unmount file servers.

▼ Refer
Data Buffering, p. 198
Chart Extensions,p. 196

Chart usually performs better with more memory. You can reduce thememory required for the Chart window buffer and speed up display byshrinking the Chart window and reducing the color depth of thedisplay. Chart extensions (software plug-ins that add features to Chart)
use up allocated memory and may slow down Chart: you should only
use those that you need. Using computed inputs, or digital filters on
many channels also limits sampling rates.

Interruptions
Some activities may interfere with the transfer of information from thee-corder to the computer, possibly resulting in a loss of data. Whenrecording critical data, avoid copying to and from floppy disks, orusing applications that access the hard disk frequently (using virtual
memory with many programs open has the same effect). Unusual
network activity and screen savers may also cause performance
problems, especially at higher sampling rates.

Recording Length▼ Refer
Data Buffering, p. 198

32

How long you can record for depends primarily on the free space you
have in which to record. Chart can record to disk (the default, usuallyChart Software

allowing for longer recording) or RAM (may be useful if your disk driveis slow) as set up in the preferences for data buffering.
Recording limits also depend on the sampling rate, the number ofchannels sampled, and the extent to which Chart compresses the data.
Each sample takes at most four bytes of storage (with no compression),so recording on one channel at 100 000 samples per second forexample would use 1 × 100 000 × 4 = 400 000 bytes (400 K) of
memory per second, or 24 megabytes per minute.
Compression takes place during recording. The compression efficiency
depends on how the signal varies: signals that change very slowly,
such as a straight line or gradual curve, can be compressed a greatdeal, while complex and rapidly changing signals may not compress
much at all. The extent of compression, as well as the amount of freespace and number of data points, can be seen by recording some dataof the type in which you are interested, then selecting Chart > About
Chart… to view the results.

Figure 2–13
The lower portion of the
About Chart dialog box.

Recording to RAM
Recording to RAM (physical memory) may be faster than recording to
disk when using a slower computer. However, the benefits will belimited by the amount of RAM you have; if you need more space for the
file you are recording than there is RAM, Chart will start using virtual
memory, which accesses the hard disk anyway. You should also notethat when you are recording to RAM, your data will be lost in the eventof a power failure or system crash.
Chart uses some memory for an off-screen buffer to speed up data
display. If the Chart window is large, more memory is used, especiallyat increased color depths. If the system is short on memory, you can use
a little less by shrinking the Chart window to a smaller size andreducing the color depth of the display.

Chapter 2 — Introduction to Chart

33

Recording to Disk
If you record to disk, you are only limited by the amount of free spaceon your disk. Computers almost always have more disk space thanRAM, and data buffered to disk by Chart can survive a system crash or
power outage, so recording to disk is a better choice unless theslowness of your computer forces you to record to RAM.
Chart has application limits of 16 000 or so blocks of data per channel
and 256 000 000 samples per channel. The blocks are either definedby the user (starting and stopping recording and so on), or internally by
Chart, which records continuous data in blocks of 16 000 samples at
all sampling rates. Note that only the user-defined blocks are marked
visually or used for selection purposes. At four bytes per sample, thisgives limits of 976 MB per channel. The maximum file size for a Chart
file would therefore be 15.2 GB with no compression (for 16 channels);but Chart limits maximum file size to 2 GB after compression. Chart will
give an alert and stop sampling when it reaches this limit.

▼ Refer
Memory Cache, p. 198

34

Files recorded by most users will typically be a lot smaller than theabove limits. If you do record very large files (of the order of 1 GB),note that performance and manageability can be affected; for instance,saving could take a few minutes, during which recording would nottake place. It is probably more convenient to save a large, long-term
data recording as a series of smaller files, using macros. If yourcomputer is taking a lot of time to perform actions on large files, it may
help to change the size of the memory cache (Chart > Preferences >Memory Cache…).

Chart SoftwareC H A P T E R

T H R E E

3 Setting Up Chart

Chart gives easy access to basic settings and also offers a flexible
array of setups suitable for different types of data.

This chapter describes basic settings controls such as the sampling rate
and the channel range, together with features such as input
amplification, units conversion, triggering and stimulation.

Chart Software

35

Setting Sampling Rates▼ Refer
Channel Settings, p. 51

You can choose the sampling rate using the Rate pop-up menu at the
top right of the Chart window. If the pointer is not over the data display
area or Time axis, the sampling rate (the number of samples taken perunit time) and the scrolling speed (the time taken for each graticule
division to scroll past) are shown in the Rate/Time display beside the
pop-up menu. The sampling rate is usually the same for all channels,
but can be set independently for each.
Rate/Time display

Figure 3–1
The Rate pop-up menu
and the slow submenu.

Select a sampling
rate directly bychoosing it

Figure 3–2
The graticule: with thedisplay at 1:1, it is one
division wide.
Division

Display While Sampling
Normally signals are shown as scrolling across the data display areafrom the right to left. The data display area is marked into divisions by
a graticule, or grid.
Divisions are always 20 pixels wide at any horizontal scale, and aremarked by the dot graticule in the data display area (they line up withunit divisions on the Time axis). The time taken for each graticule
division to scroll past depends on both the sampling rate and thehorizontal scale set using the View buttons. The compression indicatedin the View buttons indicates the samples per pixel: at 1:1, each pixel

36

Chart Softwarerepresents one sample, and there are 20 samples per division; at 20:1,
each pixel represents 20 samples, and there are 400 samples per
division.

Maximum Sampling Rates
The Rate pop-up menu lets you directly choose continuous sampling
rates of from one sample per second up to 200 000 samples per
second on one channel, 80 000 on two, 40 000 on three or four.

▼ Refer
Performance, p. 31

Maximum sampling rates may also be limited by the speed of thecomputer. When Chart starts up, it gauges the performance of thecomputer system at a range of tasks, and works out its probable limits
when sampling data. Chart gives an alert if these limits are exceeded.

Slow and Fast Sampling Rates
Chart offers a Slow Sampling submenu, which has the following rates(Figure 3–1): one sample every 2 s, 5 s, 10 s, 15 s, 30 s, 1 min,
2 min, 5 min, 10 min. Note that at these slower sampling rates, thee-corder actually samples more quickly and returns an average value.

Fast Sampling
At faster rates Chart doesn’t scroll from right to left when drawing dataon the screen, instead, the signal is drawn on screen from left to right,
and when the right edge is reached, drawing starts again at the left (avertical line precedes the newly drawn data crossing the screen). The
effect looks like a series of sweeps are being made even though therecording is actually continuous. In addition, the graticule is not drawn
while sampling, and the data are automatically scaled (compressed)
horizontally, the amount depending on sampling rate. The exact speed
at which this happens is dependent on the speed of the computer, andis necessary as very fast scrolling signals could not be adequately
displayed as a continuous movement.

Chapter 3 — Setting Up Chart

37

Channel Controls

Figure 3–3
Channel pop-up menus:
Range, Channel
Function, and Color.

Each channel in the channel control area has three pop-up menus,
Range, Channel Function, and Color. Clicking the Range pop-up menu
lets you select the channel’s input range. The default setting is 10 volts(this means from –10 V to +10 V). For the best resolution, the amplitudeof the signal you are interested in should be reasonably close to thechosen range without the risk of exceeding it. If the signal is too large
or small at a range, select a more appropriate value. Clicking thechannel title or the button at its right opens the Channel Function pop-up
menu, which gives access to the other channel controls, described
below.

➠▼ Refer
Waveform Color, p. 72

Click here
to openthe Range
pop-upmenu

Click here toopen theChannelFunction popup menu➠

Color popup menu

Turning Channels Off and On
The number of channels on when Chart starts up will be the same as thenumber of inputs on the connected e-corder. These channels will be set
to record the raw data from the corresponding inputs. The rest of thechannels, if any, will be off. Chart can display 16 channels. The
number of channels that can be turned on, though, depends on theattached e-corder. When first turned on, any spare channels will be set
to record from e-corder Input 1. They can be used for any computed
function as required, though, using raw data from any input. Channels
can display calculations even when turned off.
38

Chart Software▼ Refer
Channel Settings, p. 51

Choosing Channel Function pop-up > Turn Channel Off turns thechannel whose pop-up menu was used off. The menu command thenbecomes ‘Turn Channel On’, and if chosen, turns the channel on again.
Choosing the Input Amplifier… or Computed Input… menu commands
will also turn the channel on before they open a dialog box, since thechannel must be on for these dialog boxes to be used. Channels can beturned off or on while you are recording — this creates a new block in
the record. You can also turn channels on and off using the On column
in the Channel Settings dialog box.
There is a shortcut for dealing with multiple channels. If you hold down
the Command key while opening the pop-up menu for a particularchannel, the menu command will be plural: choosing it will turn thatchannel and all those below it off, or those with visible data on. Whena channel is turned off, its Channel Status indicator is an open diamondrather than a solid one, its Range pop-up menu button becomes
dimmed and inactive, and its Range/Amplitude display is replaced by‘Channel Off’ instead of a range when not recording.
While recording normally, the amplitude of the signal being recorded isusually shown in the Range/Amplitude display at the right of eachchannel, but if a channel is off, this display stays blank. The data
display areas of channels that are turned off appear gray while
recording, and afterwards, the areas in the record where a channel
was turned off appear blank (there is neither graticule nor data).

Figure 3–4
Data display during
recording (top) and afterrecording (bottom) with achannel off.

The Range pop-up menu isdimmedThe Channel Statusindicator is open
The channel turned off isgray while recording

The block line in Channel 1
shows starting and
The blank area in Channel
2 shows nothing was

Chapter 3 — Setting Up Chart

39

Other Functions
The other functions in the Channel Function pop-up menu are describedbriefly below, and more fully elsewhere. Channels unable to be turnedon have no Input Amplifier or Computed Input access.
▼ Refer
The Input Amplifier,p. 41

Input Amplifier… opens the Input Amplifier dialog box, which lets youchange input settings, apply signal filtering, and so on, and see theeffects before recording.

▼ Refer
Computed Input, p. 153

Computed Input… opens the Computed Input dialog box, which lets
you process signals as they are recorded, converting the sampled raw
data from any input into computed data. The menu command is ticked
if the channel has computed input applied.

▼ ReferUnits Conversion, p. 46

Units Conversion… opens the Units Conversion dialog box, which lets
you scale or convert the standard voltage reading for a channel into
useful units, such as mmHg, kPa, and so on, and lets you use waveform
measurement to calibrate the channel.

▼ Refer
Channel Calculations,p. 167

No Calculation is ticked if it is chosen, and means the displayed data inthe channel is the recorded data (either raw data or computed data)with no extra calculation (such as Smoothing, Arithmetic, Cycle
Variables, Differential or Integral) applied. It is the default setting.
Smoothing… opens the Smoothing dialog box, which lets you apply a
calculation to smooth the recorded waveform in a channel.
Arithmetic… opens the Arithmetic dialog box, which allows you toarithmetically combine data in different channels.
Cycle Variables… opens the Cycle Variables dialog box, which allows
you to analyze periodic waveforms.
Differential… opens the Differential dialog box, which allows you to
calculate the first time derivative of data in a channel.
Integral… opens the Integral dialog box, which allows you to calculate
time integrals with various resetting methods.

40

Chart Software

Chart extensions can add further channel calculations to the lower halfof the Channel Function pop-up menu. In all cases, the menu commandfor the calculation that applies will be ticked.

The Channel Status Indicator
The Channel Status indicator is a diamond at the right of the channel
control area for each channel. It is solid if the channel is on, open if thechannel is off, and contains an = sign if a channel calculation isapplied. Clicking the indicator pops up a list showing the sampling
rate, range, what is to be recorded (raw data or a computed function,and from which input), Input Amplifier settings, such as eDAQ Amp or
Pod settings, filter settings, and any active units conversion or channel
calculation. This will apply to newly recorded data.

The Input Amplifier
The Input Amplifier dialog box allows software control of the input
amplifiers and filters in the e-corder itself. Each input is set up
independently. The signal present at an input is displayed so that you
can see the effects of changes straight away. The Pod Scan button only
appears if the e-corder has pod connections. The Input Amplifier dialog
box appears when you choose Channel Function pop-up > Input
Amplifier… (or click the Input Settings column in the Channel Settings
dialog box). By default, Chart channels record data from thecorresponding e-corder inputs. To set up the inputs quickly, click thearrows at the top left, or click the right or left arrow keys on the
keyboard, to move to the dialog boxes for adjacent channels. This skips
channels that are turned off.

Signal Display
The input signal is displayed so you can see the effect of changing thesettings — no data are in fact recorded when setting up the input
amplifier. To avoid aliasing, the input signal is sampled at 10 kHz.
Each pixel width in the display thus represents a number of samples,and so is drawn as a vertical line from the minimum to maximum
recorded values. Slowly changing waveforms are shown reasonably
accurately, but quickly changing signals display as a solid area
showing only the envelope (overall shape) of the signal. The average

Chapter 3 — Setting Up Chart

41

Figure 3–5
The Input Amplifier
dialog box.

Amplitude axis

Signal Amplitude
Range
pop-up
Filtering
optionsSignalrange
Signalinput
controls

Pause/Scroll button

signal amplitude is indicated by a horizontal dotted line, and its
numeric value is shown above the display area.
You can stop the signal scrolling by clicking the Pause button at the top
right of the data display area (it looks like the pause button on a tapeor CD player). It then changes to the Scroll button (like the play button
on a tape or CD player): click it to start scrolling again.

▼ Refer
The Amplitude Axis,
p. 73

42

You can shift and stretch the vertical Amplitude axis to make the bestuse of the available display area. It is much the same as the Amplitude
axis in the main window, and the controls, such as the Scale pop-up
menu, function identically. There are also scaling buttons (up and downarrows) which double or halve the scale respectively. When the
Amplitude axis is set to a scale that differs from the range, the signal
shifts, expands or compresses (depending on how the amplitude axis isscaled) as it moves from right to left across the signal display area. This
is to indicate the difference between scale and range. Changes madeto the Amplitude axis here are reflected in the Chart window.

Chart Software

You can change the horizontal compression of the displayed signal byusing the View buttons, which are similar to those in the Chart window.
Click the left (far mountains) button to see more data in the display atonce, and click the right (near mountains) button to see less.

Filtering
The AC Coupled checkbox provides each input with a high-passfiltering option. Low-pass signal filtering options are provided by a Filter
pop-up menu. There is also a mains filter option available. (Youre-corder Manual gives technical details on filters.)
AC Coupled. Unless the AC Coupled checkbox is selected, the input
amplifier will be DC coupled, and pass both DC and AC signals.
When AC coupling is used, a high-pass filter before the first
amplification stage removes any DC and low-frequency components
from the input. The cut-off frequency is 0.1–0.5 Hz, depending on thee-corder. The AC coupled option is useful to remove a slowly changing
signal component (when recording a fast signal superimposed on a
slowly drifting baseline, for instance).
Low-Pass Filtering. The Low Pass pop-up menu gives a choice of lowpass filters from 2 kHz down to 1 Hz to remove high-frequency
components from an input signal. These filters are commonly used to rid
a signal of excessive noise. To turn the filters off, and use the maximum
bandwidth of your e-corder (approximately 20 kHz), select Off from the
pop-up menu.
These filters are implemented as digital filters within the e-corder anduse some of its processor power. If you are using the digital filters on
several channels along with computed functions, you may not be able
to use the fastest sampling rates, or you might have to turn off one ormore channels in order to sample.
Mains Filter. By selecting the Mains Filter checkbox, you can filter out
mains hum (typically seen as noise, with a frequency of 50 or 60 Hz,
superimposed on your signal). Note the mains filter uses some of thee-corder’s processing power and therefore reduces the maximum rate at
which you can sample. If your signal is noise-free, leave the mains filter
off, and if your signal is affected by mains noise, try removing possible
sources before resorting to using the filter.

Chapter 3 — Setting Up Chart

43

Signal Input Controls▼ Refer
Channel Controls, p. 38

The Range pop-up menu lets you select the input range or sensitivity of
the input. Changing the range in the Input Amplifier dialog box isequivalent to changing it in the Chart window.
The Positive and Negative checkboxes control the signal input on an
e-corder with positive and negative (that is, differential) inputs. Thesecheckboxes do not appear where the input is only single-sided: in thiscase, the input functions as if the Positive box were checkedpermanently. The two checkboxes allow you to set up three possible
input modes.
Positive. When only the Positive checkbox is checked, only the positive
inputs on the front of the e-corder are used, and a positive signal fed
into one will be shown as a positive signal on the display (noninverting).
Negative. When only the Negative checkbox is checked, only thenegative inputs on the front of the e-corder are used, and a positive
signal fed into one will be shown as a negative signal on the display(inverting).

Note
The term ‘differential’
here should not be
confused with thecomputed input
differential, which is thetime derivative, not adifference.

Differential. When both the Positive and Negative checkboxes arechecked, both positive and negative inputs are used, and the signal
shown in the channel display is the difference between the signals at
the corresponding positive and negative inputs. If both input signals
were the same, they would cancel each other out.
The Invert checkbox lets you invert the signal on the screen. It provides
a simple way to change the polarity of the recorded signal without
having to rewire a circuit or reconnect to the signal source. For
example, you might be recording from a force transducer where an
increase in force downwards gives a negative signal, but you want tohave a downwards force shown as a positive signal on the screen.
Selecting the Invert checkbox would change the display to do this.

Other Features
Display Offset. Clicking the Display Offset… button causes the Voltage
at Input dialog box to appear. In the dialog box, a voltmeter displays

44

Chart Software

Figure 3–6
The Voltage at Input
dialog box.

the signal currently being measured at an e-corder input (the input isindicated at the top of the dialog box). If a transducer or some otherexternal equipment has offset adjustment capabilities, you can use thisto help see when the device is zeroed.
This dialog box is not a control, simply an indicator that acts like a
voltmeter. It is unavailable when the AC Coupled checkbox is selected,
since AC coupling removes all DC current, and there would be no offset
to measure.
▼ ReferUnits Conversion, p. 46

Units. Clicking the Units… button opens the Units Conversion dialog
box, letting you specify the units for a channel, and, using waveform
measurements, calibrate the channel. The waveform currently in thedata display area of the dialog box is transferred to the data display
area of the Units Conversion dialog box. (Use the Pause button tocapture any specific signal that you want to use.) Units conversion will
only apply to subsequently recorded signals. This is the usual way to set
up sampling parameters.
Pod Scan. Clicking the Pod Scan button updates the dialog box if it has
been left open and a pod (a type of signal conditioner) has beenconnected or disconnected.

Zeroing Inputs
eDAQ Amps and pods (signal conditioners) connected to e-corder
inputs may replace the Input Amplifier dialog box with a dialog box

Chapter 3 — Setting Up Chart

45

specific to the device, with controls for extra filtering, offsetting, and soon (but most functions will be similar). Some eDAQ Bridge Amps and
GP Amps, have automatic zeroing to remove transducer offsets — see
their manuals for details. Choose Setup > Zero All Inputs to have each
eDAQ Amp automatically zeroed in turn.

Units Conversion
Units conversion lets you convert the standard voltage reading for achannel into suitable units for display. You can calibrate the channel
using waveform measurements or known relationships. The conversion
can be applied before recording, so that all subsequent recordings are
scaled to the required units, or after recording, either to the entire
channel (and all subsequent recordings) or to particular blocks of data.
Each channel is set up independently.
To open the Units Conversion dialog box (Figure 3–7) directly, choose
Channel Function pop-up > Units Conversion… for a channel. You canFigure 3–7
The Units Conversion
dialog box.

VoltagevaluesNew units
valuesUnits pop-up
menu

Units decimal
place control

Calibration Type
pop-up menu
ValuebuttonDifference
buttonWhat isconvertedUnits(beforeconversion
is applied)

Channel title
Click to apply the conversion

46

Amplitude axis

Maximum, mean and minimum values in selection

Chart Software

also click the Units… button in the Input Amplifier dialog box or click
the Units column in the Channel Settings dialog box.
After you choose the Units Conversion… menu command directly, theselection in the Chart window is shown in the data display area of the
dialog box. That area appears blank, or may contain a message, if
there is no selection or a discontinuous one (over two or more blocks). If
there is a selection point or area, you can choose to convert the units ofthe selected block or blocks of data; else the Selected Blocks radio
button is dimmed and can’t be chosen. If the dialog box is opened fromthe Input Amplifier or Channel Settings dialog boxes, you can convert
only the units of subsequently recorded signals: you can’t convert blocksof data or the whole channel, and the dialog box appears with noradio buttons.

▼ Refer
Signal Display, p. 41

Using the Units… button in the Input Amplifier dialog box transfers thedata shown there to the units conversion data display area (Figure3–8). This has a slightly different aspect ratio to the original display
area, but the signal is also drawn differently. Lines are drawn
connecting the minimum values and connecting the maximum values,
and the area between them is shaded. This gives a truer representationof the signal envelope than is possible in the Input Amplifier dialog box.

Figure 3–8
A signal transferred fromthe Input Amplifier dialog
box to the units
conversion data display
area.

Converting Quantities
The dialog box has four text entry boxes: actual voltages go in the leftboxes, and what those readings are equivalent to goes in the rightboxes. Each box requires an entry, so that there are two sets of values
to calculate the scaling between volts and the new unit. (It must be a
linear relationship to work. Note that if the slope is negative, theAmplitude axis will be inverted.) You can type in some or all values in
Chapter 3 — Setting Up Chart47

the boxes directly, or use some readings from the data display area inthe left boxes and type in known conversion values in the right boxes.
Click the Apply button to see what the converted data look like. Clickthe OK button to convert the data into the chosen units, or Cancel toclose the dialog box without making changes.

Entering Values
If you know the relationship between what is measured and thedisplayed voltage, then you can directly type in values in the four boxes(you can press Tab to move between the fields, left to right, top tobottom). If you are using a temperature transducer and calibrationshows that a temperature of 10 °C gives a reading of 1 volt, and 30°C gives 3 V, say, then you can key in the values (left to right, top tobottom: 1 V, 10; 3 V, 30), and choose °C from the Units pop-up menu.
ValuebuttonDifference
buttonYou can set up units conversion using values from data points,
averages, and changes in the waveform shown in the data display
area. The Data Use pop-up menu changes which buttons are available
for data transfer: either Point 1 and Point 2 or Point 1 and Difference.
This in turn fixes how displayed data are used: you can either use twodata points (or averages) or a point and a difference to fix the scaling
for the conversion. (At least one base value must be absolute.)
You can shift and stretch the vertical Amplitude axis to make the bestuse of the data display area. It is the same as the Amplitude axis in themain window, and the controls function identically. If you click in thedata display area, a vertical line indicates the active point, and an
indicator arrow at the right of the data display shows the point ofintersection with the waveform (Figure 3–9, ➊). If you make a selectionin the data display area, the indicator arrow at the right of the data
display shows the average amplitude of the waveform, and twomarkers above and below it indicate the maximum and minimum data
points in the selection (Figure 3–9, ➍).
If there is an active point or a selection in the data display area, thenclicking the Value button enters the voltage value (at the active point, orthe average of the selected data) in the left box in its row. Clicking theDifference button enters the difference between the maximum andminimum of the selection in the left box in its row. Differences areindicated by a delta prefix (∆). In each case, the right box of the row is
selected so that you can type in the known value in the new units. As a

48

Chart Software

Figure 3–9
Selections in the data
display area of the Units
Conversion dialog box.

➊

➌

➋

➍

shortcut, you can double-click in the data display area to transfer thedata at a point in one step (doing this a second time enters data in theunused row).
To calibrate a force transducer in a channel, say, start recording andapply two known forces to the transducer, to get two voltages. Stop
recording, select the area with the two readings, and choose Channel
Function pop-up > Units Conversion… for the channel. Choose Data
Use pop-up > 2 Point Calibration in the dialog box. Select a point or
area in the waveform corresponding to one force (Figure 3–9, ➋), clicka Value button to enter its value in a left box, and type the known force
in the right box beside it. Repeat the process for the other force (Figure
3–9, ➌), entering data in the unused row.
If you know the relationship between what is measured and thedisplayed voltage, but don’t have two sets of values, you might use thePoint and Difference option. For example, some temperaturetransducers produce a certain change in voltage for a given change intemperature (such as ∆20 mV giving ∆4 °C). Use an absolute readingin the top row (a calibration value, perhaps). Select an area in the data
display where a known change in temperature has been recorded(Figure 3–9, ➍). Use the Difference button to enter the difference invalues in the selected data in the left box of the bottom row, and typethe known change in the right box.

Chapter 3 — Setting Up Chart

49

Choosing Unit Names
The Unit pop-up menu lets you choose, define, or delete units. Units are
just names, and the conversions are set independently, so you could
have °C in two channels, say, with different conversions. Unit names
are stored in the e-corder Settings file in the Preferences folder of the
System folder, in common with those created in Scope, and areavailable to all Chart and Scope files once created (or unavailable
once deleted). Some frequently used ones are provided.

▼ ReferSuperscripts andSubscripts, p. 82

Choose Unit pop-up > Define Unit… to define new units. The Define
Unit Name dialog box appears, letting you type in up to ninecharacters for a unit, and add a prefix (there is a pop-up menu ofstandard prefixes in the dialog box; the default is none). Superscripts
and subscripts can be used, as with channel titles. Choose Unit pop-up> Delete Unit… to delete units: the Delete Unit Name dialog box
appears. Select the unit to be deleted from the scrolling field (Shift-click
or Command-click to select several) and click OK to close the dialog
box: the unit is then deleted. If you accidentally delete a unit, you must
redefine it. Double-click a unit to delete it and close the dialog box in
one step.
You can set the number of decimal places of the new units (from 0 to a
maximum of 6), by clicking the arrows at the top right of the Units
Conversion dialog box. You can turn units conversion off or on without
losing the values you have entered by clicking the Off or On buttons by
the title of the dialog box. Clicking the Apply button to see how theunits conversion will look, or the OK button to convert units and returnto the Chart window, will turn units conversion on.

Figure 3–10
Dialog boxes for defining
and deleting units.

50

Select a prefixfrom this pop-up
menuType the unit name in here —superscripts and subscripts are
possible

Chart SoftwareChannel Settings
The Channel Settings dialog box lets you set up multiple channels
conveniently: you can both see and specify recording and display
settings for each channel in the one place. To open the dialog box,
choose Setup > Channel Settings… or type Command-Y. Note thatwhen there is no e-corder connected, a smaller version with only
display settings visible will appear.

Figure 3–11
The Channel Settings
dialog box.

The functions of the dialog box and the dialog boxes it gives access toare described briefly below, and more fully elsewhere. (Most of therecording settings are discussed in detail in this chapter, and thedisplay settings in the next.) Click the OK button to apply the changes
and return to the Chart window.

Title
You can enter a title for each channel in its text entry box, replacing thedefault titles such as ‘Channel 1’.

Chapter 3 — Setting Up Chart

51

On
The checkbox lets you turn a channel off (unchecked) or on (checked). It
is equivalent to selecting the ‘Turn Channel Off’ or ‘Turn Channel On’
menu commands from the Channel Function pop-up menu for achannel. There is a shortcut for dealing with multiple channels: holddown the Command key while clicking the checkbox for a particularchannel to turn that channel and all those below it off or on. If achannel is off, its recording settings are blank and unusable.

Sampling
Sampling rates can be set using the pop-up menus in the Samplingcolumn. They let you choose any of the continuous sampling rates
available directly from the Rate pop-up menu. By default, the rate is thesame for all channels, and the Same Sampling Rate radio button at thebottom of the dialog box is turned on. Changing the rate in any pop-up
menu in the column changes it for all channels.
If the Different Sampling Rates radio button is turned on, then rates canbe set independently for each channel. You might want to do this whensome channels require high time-resolution (say, a vibration signal), butothers being recorded concurrently do not (say, temperature). Chart
samples on all channels at the maximum rate chosen for any of thechannels, but interpolates rather than records some data points inchannels with lower rates, enabling better data compression. Reducing
the sampling rate for some channels therefore will not solve problems
with the rate being too fast (you need to turn channels off for this); it justcreates smaller data files.
When some channels have different sampling rates, the Rate/Time
display in the Chart window shows the maximum rate. Clicking the Rate
button will not open the Rate pop-up menu in this case: rather, thebutton highlights, and when the mouse is released, the Channel Settings
dialog box appears. Clicking the Same Sampling Rate radio button will
set all channels to the maximum rate.
The pop-up menus in the Sampling column do not include the Slow
Sampling submenu from the Rate pop-up menu. If a slower or fastersampling rate is set from the Chart window using these submenus, thenthe radio buttons at the bottom of the dialog box will be dimmed andunusable, and the pop-up menus in the Sampling column will be blank
52

Chart Software▼ Refer
Channel Titles, p. 81
Turning Channels Off
and On, p. 38
Setting Sampling Rates,
p. 36

and also unusable: slow sampling rates must be the same for all
channels.

Range
The pop-up menus in the Range column let you select the input range orsensitivity of each input. Changing the range is equivalent to changing
it in the Chart window. For those channels with computed inputs, theranges will be the computed input ranges.

Input Settings
Click the Input Settings column to open the Input Amplifier dialog box
for an input, letting you change input settings, apply signal filtering,and so on, and see the effects without recording. This is the same aschoosing the Input Amplifier… command from a Channel Function popup menu. By default, Chart channels record data from thecorresponding e-corder inputs. The channel entry will change to show if
an eDAQ Amp such as the pH/mV Amp is connected; so this column isuseful to check to see if multiple eDAQ Amps are connected properly tothe e-corder and are on.

Computed Input▼ Refer
Channel Controls, p. 38
The Input Amplifier,p. 41
Computed Input, p. 153
Units Conversion, p. 46

Click the Computed Input column to open the Computed Input dialog
box. This is the same as choosing the Computed Input… command froma Channel Function pop-up menu. The dialog box lets you choose toprocess signals as they are recorded, converting the raw data from any
input into computed data. Raw Data means the sampled data with nocomputed function applied, and is the default setting. The channel entry
displays the computed function being applied, if any, and the input
from which the raw data came. The column is a useful way to check
what is going on in each channel.

Units
Click the Units column to open the Units Conversion dialog box for achannel, letting you change the standard voltage reading for a channel
into useful units, such as °C, µA, kPa, and so on. This is similar tochoosing units conversion through the Input Amplifier dialog box, andChapter 3 — Setting Up Chart

53

applies only to subsequent recording. If units conversion has not been
applied, the default units are shown in the column in italics.

Color
The pop-up dialog boxes in the Color column let you choose the colorof the data trace in a channel, and whether the data points are
displayed joined by lines or as unjoined dots. You can also set here thethickness of the data trace that appears in the Zoom window (datatraces are always drawn one pixel thick in the Chart window).

Calculation▼ Refer
Display Settings, p. 77
Channel Calculations,p. 167
Changing Channel Size,
p. 75

The pop-up menus in the Calculation column let you apply calculations
to channels of recorded data. The options are the same as those in thelower half of a Channel Function pop-up menu. No Calculation is thedefault setting, and means the displayed data in the channel arerecorded data (either raw data or computed data) with no extra
calculation applied. Chart has the Smoothing, Arithmetic, Cycle
Variables, Differential and Integral calculations available, and Chart
extensions such as Spirometry can add others. The calculations do not
replace the recorded data in a channel, and can be used in channels
that are turned off. They may be online (you see the results as you
sample) or offline (you see the results of the calculation only after
sampling finishes).

Separator
The checkbox lets you turn a channel separator off (unchecked) or on(checked). Turning off the channel separator between two channels
overlays them in the Chart window, allowing you to compare theirwaveforms directly: the line between channels in this dialog box also
disappears so that the setting is easy to see at a glance.

Number of Channels
This control, at the bottom of the dialog box, lets you choose thenumber of channels displayed in the Chart window. It both turns themoff, so that no data are recorded, and hides them, so that the data
display area is not cluttered with channel separators. Click the up or
down arrows to increment or decrement the number, or type a value in

54

Chart Softwarethe text box directly. The lower channels are turned off and hidden first:
their rows are blank and borders grayed out, so that they can be
distinguished from channels that are off.

Triggering
Triggering determines the way Chart starts and stops recording. A
trigger is an event such as clicking the Start button or a voltage abovesome preset threshold in an incoming waveform. To set up triggering,choose Setup > Trigger: the Trigger window appears. You can use thecontrols to set up the type of trigger event you want, the delay until
recording, the duration of recording, and so on.
The Trigger window is a normal window, and can be moved aroundthe screen or left in the background while the Chart window is active.
By default, the Source and Stop pop-up menus are set to User, and theother controls are dimmed. In this case there are no special trigger
conditions, and recording starts or stops when the Start or Stop buttonin the Chart window is clicked.

Choose the trigger state change
here: up for +ve, down for –ve

Figure 3–12
The Trigger window.

ChoosehowChartreacts to
the trigger
event here
Set thestopping
condition
hereEnter the number of blocks after which to stop
recording here (for multiply triggered events)

Chapter 3 — Setting Up Chart

Set the starting
condition here
Use theslider bar
or text
entry box
to settriggering
voltageUse thearrow
buttons ortext entry
boxes toset times

Use this pop-up menu to mark the event ina channel

55Setting the Controls
Source
You can choose the event that triggers recording from the Source popup menu, which gives you the choice of User, Ext Trigger, Internal
Timer, or one of the Chart channels. If you select User or Internal Timer,
Chart starts recording when you click the Start button.
If you choose one of the other options, clicking the Start button gets
Chart ready to record: the Recording Status indicator shows themessage ‘Waiting for trigger’, and the Record/Monitor button will bedimmed. The chosen trigger event then starts Chart recording.

▼ Refer
External Trigger, p. 190

If you select Ext Trigger, the event comes from an external source
connected via the Trigger connector on the front of the e-corder. When
External Trigger is selected in the Trigger dialog box, an Options...
button appears. Clicking this button allows you to choose between TTL
Voltage Level (a voltage pulse), and Contact Closure mode (when acontact is made between the two terminals of the input cable). An
external voltage pulse must be over about 3 V for 5 µs or longer toregister (see your e-corder Manual for details. Many instruments
provide either TTL or contact closure trigger signals and these settings
can be used to synchronize the Chart recording with such devices.
Note that the external trigger does not function at a sampling rate of
200 000 samples per second.
If you choose a channel, a voltage above some threshold in the signalof that channel starts Chart recording. The channel must be turned on
for its signal to be chosen as a triggering event.
The Source time controls are only active when Internal Timer is selectedin the Source pop-up menu, and are used to set the intervals at which
recording starts. Click the up or down arrows to increment ordecrement the numbers, or type values in the text boxes directly. Theinternal timer requires fixed-duration sampling. Chart records a block of
the set duration, then counts down until the time set with the Source time
controls has passed. After recording, the Recording Status indicatorshows the message ‘Int. Timer’ and the time remaining. Chart thenrecords another block, and so on until the number of blocks set in the
Stop Cycling control is reached or the Stop button is clicked, at which
stage recording stops.

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Chart Software

The internal timer is not intended for uses requiring very high accuracy.
It should be accurate to a quarter second, as a rule, but since it iscontrolled from the computer, its accuracy depends on how fast thecomputer is, and how busy. Holding down a menu may delay theinternal timer until the menu is released, for instance.

Slope and Level
When Ext Trigger or a channel is selected in the Source pop-up menu,
the slope of the triggering voltage can be set. The trigger level is anabsolute voltage: the slope determines whether triggering occurs whenthe voltage goes up (positive) or down (negative) through the trigger
level. The active Slope button is highlighted: click the inactive button tochange the slope.
The Level controls are used to set the trigger level voltage for a channel
when one is selected in the Source pop-up menu (else it is dimmed). The
range of voltages available depends on the range set for the trigger
channel. You can either use the slider bar, enter a value directly in the
text box or use the arrows beside it to change the trigger level.

Start
When Ext Trigger or a channel is selected in the Source pop-up menu,
the Start pop-up menu becomes active. It offers the choice of At Event,Post-Trigger, or Pre-Trigger, to determine how Chart reacts to the trigger
event, that is, whether there is a period of time between the triggering
event and the start of recording.
When At Event is selected, sampling starts as soon as the trigger event
occurs, and no Start time controls appear. When Post-Trigger isselected, sampling starts at the time set with the Start time controls after
the trigger event occurs. This is useful in cases of delayed response, if
the signals you want to record will occur some time after the trigger
event. When Pre-Trigger is selected, sampling starts before the trigger
event occurs. Anticipation is limited to 16 000 samples (at present),since it relies on data buffered in memory, so the available time range
for Pre-Trigger recording depends on the sampling rate. Pre-triggering isuseful to record the onset of an event before the trigger level voltage isreached. It may result in negative values in the Time axis for the timepreceding the trigger event (which takes place at zero time in sometime modes). Pre-triggering ignores trigger events that occur before theChapter 3 — Setting Up Chart57

pre-trigger time is up, rather than starting if a trigger event occurs withinthat time. If you set the pre-trigger time to 5 seconds, say, Chart will
sample for 5 seconds before even looking for a trigger.
The Start time controls are used to set the time before or after the trigger
event when recording starts, and are only visible when either PostTrigger or Pre-Trigger is selected in the Start pop-up menu. Click the up
or down arrows to increment or decrement the numbers, or type values
in the text boxes directly. If the time set exceeds the limit for pretriggering, then when sampling starts it will be reduced to a shorter time(and Chart will alert you to the fact).

Stop
You can determine how Chart stops recording using the Stop pop-up
menu: User, Fixed Duration, or End of Trigger. When User is chosen,
recording continues until you click the Stop button (or memory runs out),
and the Stop time controls are unavailable. When Fixed Duration is set,recording continues for a set period after the trigger event occurs.
When Internal Timer is set in the Source pop-up menu, the Fixed
Duration option is set automatically: if you change the option, you get
an alert when you try to sample. When End of Trigger is selected,
recording starts at the trigger event, and continues for a set period after
the end of the trigger event (when the voltage passes through thetrigger level again). If multiple trigger events occur during recording,recording continues until the set period after the end of the last one.
You might use this to record while a nerve was firing, for example, andfor some time afterwards: recording would start when the nerve
potential starts, and stop a set time after the nerve potential falls below
a certain value.
The Stop time controls are used to set the time for which recording
continues, and are only visible when either Fixed Duration or End of
Trigger is selected in the Stop pop-up menu. Click the up or downarrows to increment or decrement the numbers, or type a value in the
text boxes directly. You should check to see if there is enough memory
to record for the time entered (since Chart does not). The internal timer
requires the value set in the Stop time controls (the time for which torecord) to be less than the value in the Source time controls (the time
between each cycle). If you set the stop time to more than the timer
cycle, you get an alert when you try to sample. If you set it to zero,Chart still records two samples per cycle.

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Chart Software

Stop Cycling
The Stop Cycling control lets you set up triggering for repeated events.
The checkbox can be turned on or off when Fixed Duration is set in the
Stop pop-up menu, and User is not active in the Source pop-up menu.
Otherwise it is dimmed and unable to be used.
If the checkbox is off, then Chart just records a new block (of theduration fixed with the Stop controls) for each specified trigger event
until it reaches its recording limits. If used with the internal timer, Chart
starts recording a new block at each interval set in the Source time
controls. If the trigger event is the external trigger or a channel voltage,then Chart starts recording a new block at each such event (ignoring
those events that occur while already recording). This is obviously usefulto record a series of sporadic events, for example.
If the checkbox is on, then you can enter a number in the text entry box
to specify the number of blocks to record, from 1 to 16 000 (about the
maximum number of blocks in a Chart file). Chart will record that
number of blocks before it turns off.

External Trigger Marker
If you choose a channel from the External Trigger Marker pop-up menu,
then the point when an external trigger pulse occurs is marked by asmall data spike (this adds to any data in the channel). If you choose
Off, no mark is recorded. The external trigger marker does not work at
fast sampling rates (over 1000 samples per second).
You do not need to start sampling with the external trigger to use themark; you could note the beginning of some phase of an experiment, or
mark a particular event automatically at the instant it occurs by using asignal source connected to the external trigger. Unless you needed
extreme accuracy, though, you would usually use comments or
automatic comments for this purpose.

Making Changes in the Chart Window
If you have selected channel event triggering, you can change thetrigger level voltage and slope, and the event channel, from the Chart
window. If channel triggering is active, the Trigger Marker (an arrow, a
T, and a triangle) is shown in the (vertical) Amplitude axis of the event
Chapter 3 — Setting Up Chart

59

channel with the triangle pointing at the triggering voltage level. The
trigger slope is represented by the arrow: up for positive and down for
negative.
Double-clicking the Trigger Marker changes the slope. You can dragthe Trigger Marker up or down to change its settings — a gray box andline appear, to indicate where it will go. When the box and line are at
the desired voltage in the desired event channel, release the mousebutton to apply the new settings to the trigger.

Figure 3–13
The Trigger Marker.

The Stimulator
The Stimulator lets you generate a stimulus (pulse or stepped
waveforms), through the e-corder analog outputs. Select Setup >Stimulator: the Stimulator window appears which controls set thestimulus type and properties. The stimulus (output waveform) is
generated via the sockets marked ‘Output’ on the front of the e-corder.
The stimulator settings are independent of the sampling rate, butvariable stimuli can only be generated while the e-corder is sampling,or while the Computed Input dialog box is open.

▼ Refer
The Stimulator Panel,
p. 65

60

The Stimulator window is a normal window, and can be moved aroundthe screen or left in the background while the Chart window is active.
Parameters can be changed while sampling occurs. By default, thestimulator is off: Off is selected in the Mode pop-up menu, and thecontrols are inactive. The active controls in the window change with thechosen mode. You can turn stimulation off or on without losing theChart Software

Figure 3–14
The Stimulator window.

Select the stimulus Click these radio buttons totype from thischoose continuous stimulation or
pop-up menu
a fixed number of pulses

ChooseSelect to use youre-corder’s built-in isolated channel instimulator (if there is one) which tomarkstimulus
Set thenumber ofpulses withthe arrows
or text box
Click to start
the stimulus(when
Manually
start mode ischosen)Set stimulus time parameters withthe slider bars or text boxes

Set stimulus amplitude parameterswith the slider bars or text boxes

values you enter. Stimulation parameters can also be controlled using
the Stimulator Panel.

Mode
The Stimulator Mode pop-up menu lets you choose the stimulus type —pulse, step, ramp, triangle, or sine, Figure 3–14. Once the stimulus
type is chosen, you can use the window controls to define its
characteristics precisely.

Figure 3–15
Types of stimulus
waveform.

Pulse

Step

Step

Ramp

Triangle

Sine

Chapter 3 — Setting Up Chart

61

Pulse. This setting generates a rectangular pulse stimulus that starts at abaseline voltage, is raised or lowered to the set amplitude for the pulse
duration, and then falls or rises to the baseline voltage again.
Step. This setting generates a stepped stimulus that starts at a baseline
voltage, is raised or lowered to the set amplitude in a series of steps,
and then falls or rises to the baseline voltage again. Each step can fallor rise to the baseline voltage if required.
Ramp. This setting generates a sloping (ramp-shaped) stimulus thatstarts at the start voltage, is smoothly raised or lowered to the end
voltage, and then falls or rises to the start voltage again.
Triangle. This setting generates a triangular wave stimulus that issymmetrical about a baseline voltage, and rises and falls for the set
amplitude from the baseline.
Sine. This setting generates a sine wave stimulus that is symmetricalabout a baseline voltage, and rises and falls for the set amplitude fromthe baseline.

Setting the Controls
The slider bars for various stimulation parameters can be used to set thevalue in the normal way, by dragging the sliding handle. The value isdisplayed in the text entry box beside the slider bar. You can alsochange the value by clicking the up and down arrows at the right of thetext entry box, or by entering a value directly.

Continuous Waveforms
By default, the stimulator gives a continuous stimulus waveform, and the
top Output radio button (at the top left of the window) will be on(Continuously for Pulse, Triangle, or Sine modes; Repetitive otherwise).
If you choose Step mode, you can specify how many steps, from 1 to
2000, you want in your stepped waveform. In Ramp mode, the control
is disabled.

62

Chart SoftwareDiscrete Waveforms
If the lower of the two Output radio buttons (at the top left of thewindow) is selected (Fixed Number of Pulses for Pulse, Once Only for
Step and Ramp, or Fixed Number of Cycles for Triangle and Sinemodes), then the stimulator will produce a set number of pulses orcycles of a waveform; or for Step and Ramp modes, a single stimulus ofvarying intensity.
If you choose Pulse, Triangle, or Sine from the Mode pop-up menu, you
can specify the number of pulses or cycles to be produced by thestimulator, from 1 to 2000, using the Number of Pulses (or Cycles)
control at the right of the window. If you choose Step mode, you canspecify how many steps, from 1 to 2000, you want in your stepped
waveform (but note that only one stimulus is produced). In Ramp mode,the control is disabled.

Marker Channel
If you choose a channel from the Marker Channel pop-up menu, thenthe point when a stimulus starts is marked by a small data spike (thisadds to any data in the channel). If you choose Off, no mark is added.
The stimulus marker marks the start of each pulse, step, or ramp, or thestart of each cycle for triangle or sine modes. It works at any sampling
rate, up to a stimulus frequency of about 10 Hz.

Start Mode
Click When recording starts to start the stimulator when the Start button
is clicked. If the stimulus waveform is continuous, the Stimulator Panel
controls will then include Off and On buttons to allow you to turn thecontinuous stimulation off and back on again.
Click Manually to start the stimulator either when the Stimulate button isclicked, either in the Stimulator window or in the Stimulator Panel. (Ifthe waveform is continuous, there will be Off and On buttons in the
Stimulator Panel.)

Chapter 3 — Setting Up Chart

63

DelayIf you wish the delivery of the stimulus waveform to be delayed after
you click Start in the Chart View, or Stimulate in the Stimulator windowor the Stimulator Panel, enter a delay time (from 0 to 1 000 000
milliseconds) into the text box.

Range, Frequency, and Pulse Duration
For Pulse, Triangle, and Sine modes, the (frequency) Range pop-up
menu lets you select the range for the Frequency control, from 2 Hz,
20 Hz, or 200 Hz. You can also choose PPM (pulses per minute), since
it can sometimes be more convenient to have frequency stated in termsof minutes. The Frequency control is used to set the pulse or cycle
frequency within these ranges, from 0.1 Hz to the maximum in eachhertz range, and from 2 to 200 pulses (or cycles) per minute in the PPM
range (about 0.033 Hz to 3.3 Hz).
For Pulse mode, the Pulse Duration control sets the time for which thepulse lasts. The time is dependent on the frequency set, since the pulse
must be less than the period of the stimulus waveform. The smallest
increment is 0.05 ms.

Range, Step Width, Ramp Duration, and Pulse Duration
For Step and Ramp modes, the (time) Range pop-up menu lets you
select the range for the Step Width or Ramp Duration controls, from 20
ms, 200 ms, 2 s, or 20 s. The Step Width or Ramp Duration controls
set the exact duration for these parameters within these ranges.
The Pulse Duration control (for Step mode) sets the time for which thepulse lasts within the step width — the pulse cannot exceed the step
width. If the pulse duration is less than the step width, then the voltage
step returns to the baseline voltage before increasing (or decreasing) to
the next step. If the pulse duration is equal to the step width, then thevoltage steps increase (or decrease), and do not return to the baseline
voltage until the whole stimulus waveform is finished.

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Chart Software

Range, Amplitude, and Baseline▼ Refer
Constant Output Voltage,
p. 66

For Pulse, Triangle, and Sine modes, the (amplitude) Range pop-up
menu lets you select the range for the Amplitude and Baseline controls.
Ranges of 200 mV, to 10 V are available. The Amplitude control sets
the exact voltage, either positive or negative, within these ranges: anegative amplitude starts triangle and sine waveforms at the negative
parts of their cycle. The Baseline control sets the exact baseline voltage
within the range: triangle and sine waveforms are symmetrical about
the baseline, and the pulse waveform just adds the (positive or
negative) pulse to it. The baseline voltage is the same output as in the
Stimulator Constant Output dialog box, and changing it in either placechanges it in both.

Range, End Level, and Start Level
For Step and Ramp modes, the (amplitude) Range pop-up menu lets you
select the range for the End Level and Start Level controls. Ranges of
200 mV, to 10 V are available. The End Level and Start Level controls
set the exact voltage level, for the starting and ending voltages of thestep or ramp, within these ranges. The start level voltage is the same
output as in the Stimulator Constant Output dialog box, and changing it
in either place changes it in both.

The Stimulator Panel
Once you have set up stimulation using the Stimulator window, you caneasily start or stop stimulation or change settings while sampling, byusing the Stimulator Panel miniwindow (see Figure 3–16). Choose
Setup > Stimulator Panel to open it.

Figure 3–16
The Stimulator Panelminiwindow.

These buttons appear
for continuous
stimulation — click tostart or stop
stimulatingThis button appears
for discrete
stimulation — click tostimulate

Chapter 3 — Setting Up Chart

65

The Stimulator Panel miniwindow ‘floats’ in front of the active window,
can be moved around with its title bar, and can only be dismissed byclicking its close button. If continuous stimulation was chosen, then the
Panel will have Off and On buttons, so you can turn stimulation off or
on at will. If you have chosen discrete stimulation, then the Panel will
have a Stimulate button: click it to deliver a set number of pulses orcycles of a waveform; or for Step and Ramp modes, a single stimulus ofvarying intensity. As a shortcut, you can type Option-space bar toactivate the panel button or buttons, to start a stimulus or turn one on or
off.
Click the up or down arrows to increment or decrement the stimulus
parameters during sampling — the set value is shown beside thecontrol (the controls appearing depend on the stimulus mode).
Changing parameters here changes them in the Stimulator window,
and vice versa.

Constant Output Voltage
Stimulation voltages are generated by the e-corder via the outputs on its
front panel. Choose Setup > Output Voltage… to set up a constant
output. The Stimulator Constant Output dialog box will appear. You can
use the controls to set continuous voltages.
The (amplitude) Range pop-up menu lets you select the range for the
Amplitude control, from 200 mV to 10 V. The Amplitude control is used
to set the exact voltage, either positive or negative, within these ranges.
The slider bars can be used to set the value in the normal way, by
dragging the sliding handle, or clicking the arrows or the slider bar
area. The value is displayed in a text box to the right of the slider bar— you can enter a value directly here. The dialog box can be broughtup during recording, so that the voltage can be adjusted, without
stopping.

Figure 3–17
The Stimulator Constant
Output dialog box.

66

Chart Software

The voltage is generated as soon as a value is set (the e-corder does
not need to be sampling to produce constant voltages, as opposed tovariable stimuli). The constant DC output voltage continues until Chart isquit or another application, such as Scope, uses the e-corder. (If you
switch out of Chart to Scope and then switch in to Chart again, Chart
will restore its set constant output voltage.)

The Stimulator Output
Output voltage signals are generated by the e-corder via the front panel
output sockets. The outputs are bipolar, thus a 1 V setting produces+1 V at the Output + connector, and –1 V at the Output – connector,(Figure 3–18). Thus you could generate up to a 20 V output by
connecting to both the Output + and Output – sockets and using a a
10 V setting.
The stimulator and constant output voltage work together: thestimulation voltage adds directly to the constant voltage, but the total of
the two cannot exceed ±10 V. The output from the Stimulator Constant
Output dialog box is the same as the Baseline voltage for Pulse,
Triangle, and Sine modes or the Start Level voltage for Step and Ramp
modes set in the Stimulator, and changing it in either place changes itin both.)Figure 3–18
A pulse with constant
output voltage setting on
the stimulator.

Output +Chapter 3 — Setting Up Chart

Output –67

68

Chart SoftwareC H A P T E R

4 Data Display

F O U R

Chart allows you great flexibility in displaying data. You can change
the lines, patterns, and colors of the data display. You can resize theChart window, expand or reduce the horizontal scaling, split thescreen, and change the size of each channel’s display, overlay
adjacent channels, or even hide them. You can look at the overall
trends in the recording, or look at a small section of data in great
detail.

This chapter describes the display options available in Chart, from thebasic settings through to Amplitude axis manipulation, channel titles,
the Zoom window and displaying digital read-outs.

Chart Software

69

The Chart Window
As well as the essential controls for recording data, many controls to set
the display format directly are provided within the Chart window.

Time Format
Click the Time & Date button, the clock at the top right of the Chart
window, to open a dialog box letting you set the time scale mode, andwhether to display the date and time when data were recorded.
Display in Chart window

Figure 4–1
The Time Format dialog
box.

Time Scale
The Time Scale controls let you choose the form and units of the Timeaxis. This applies to the whole axis, and can be changed at will just bybringing up the dialog box, since all time information about arecording is stored. The time at the pointer position along the Time axis
shown in the Rate/Time display will be in the form chosen here. These
controls are duplicated in the Display Settings dialog box, andchanging them in either place changes them in both.
From Start of Block. Time is measured relative to the start of each new
block of data (this is the default setting). Time is reset to zero at the startof each block of newly recorded data, that is, whenever Start is clicked
or recording is started by triggering or the internal timer.
From Start of File. Time is measured relative to the start of the file. Thisis useful if you want to know the amount of time lost between sampling
being stopped and started again.

70

Chart SoftwareNote
If you record new data in
old files, and choose‘From Start of File’, you
might end up with verylarge numbers towards
the right of the Time axis.
If you append data fromdifferent files, you could
even get negative times.
Check the Time display
for the dates and times ofrecordings.

Time of Day. Time is displayed as the time of day the sample was taken— it uses either 12-hour or 24-hour display depending on the settings
in the system’s Date & Time control panel. This is useful if you want toknow at what time of day an event occurred.
Always Seconds. When the time gets large enough, it is displayed inhours, minutes, and seconds unless the Always Seconds checkbox ischecked, in which case the time will be shown in decimal seconds (athigh sampling rates, measurements will be shown in milliseconds). This
checkbox is dimmed and cannot be chosen when the Time of Day radio
button is selected.

Cursor Clock
The Cursor Clock checkboxes (see Figure 4–1) control the display of thetime and date in the Chart window. If neither is selected, only the Time& Date button (the clock icon) is shown, with no text display. If one orboth is selected, the Time & Date button displays beside it the date ortime or both at which the samples at the Waveform Cursor positions
were recorded, if the pointer is over the data display or Time axis areas(otherwise the text area is left blank). This is handy for checking whendata were recorded. The formats used are those set in the Mac OS X
Date & Time System Preferences.

Split BarYou can split the data display area of the Chart window vertically, into
two sections or panes, to compare different sections of recorded data,or to compare recorded data with newly sampled data. Whenrecording, the new data are shown in the right section of the window.
You can perform most normal operations in the left-hand pane of thewindow: make selections, use the Zoom and X–Y windows, add
comments and exclusions, add data to the Data Pad, copy data toother files, change data compression, and so on.
To split the window, position the pointer on the split bar (anywhere
along its height), so that it changes into the split pointer. The vertical
split bar is at the left side of the data display area. Drag the split bar tothe desired position, so that the two panes of the window are the sizes
you want them — a gray line appears, to indicate where it will go —then release the mouse button. You can do this while recording. You

Chapter 4 — Data Display

71

Figure 4–2
Splitting the data display
area: drag the split bar
to the desired position
and release the mousebutton.

can use the scroll bars of the two panes to scroll through the two viewsof recorded data independently; keyboard scrolling commands control
the right-hand pane. Double-clicking the split bar or dragging it as far
left as it will go returns it to the ‘off’ position at the left of the data
display area, and leaves you with a single pane once more.

Waveform Color
To set the channel’s data trace color directly from the Chart window,
click the Color pop-up menu, the colored box beneath the Range popup menu, and choose one of the fifteen display colors. The pop-up
menu also lets you choose whether the data points are displayed joinedby lines (the default for Chart) or as unjoined dots. Choose Color popup > Dots to show a dot for each sampled data point in the waveform.
The menu command then changes to Line: choosing this gives you acontinuous waveform.
Lines

Figure 4–3
The Color pop-up menu.

Click here to choose
how the waveform
appears

72

➠

Dots

Chart Software▼ Refer
Color, p. 82

This Color pop-up menu is a simple version of the one that appears in
the Color column of the Channel Settings dialog box; changing thesettings in either place changes them in both.

The Amplitude Axis
The scale of the (vertical) Amplitude axis of each channel can be
independently dragged, stretched, or set through a dialog box for
optimum data display. Scale appearance options can be selected fromthe Scale pop-up menu, the button for which is located at the top left ofeach channel’s Amplitude axis. The Bipolar and Single Sided options
are disabled if units conversion is applied, or if the channel has nodata. (The Scale pop-up menu for overlaid channels shows the overlaid
channels as well, so you can see or set the active one.)Single Sided. This option can be used to view only positive voltage
signals. It shifts the vertical axis so that zero volts is located at thebottom of the display area. Any readings below zero volts will be off
the screen (to see them, select the Bipolar option or drag the scale).
Bipolar. This is the default mode for each channel in Chart. It shows
both positive and negative signals, with zero volts at the center of thevertical scale if no shifting or stretching has been applied.
Set Scale. This option allows you to adjust the Amplitude axis directly toshow the range of values you want. It works whether units conversion is
on or off. When you choose Set Scale…, the Set Scale dialog box forthat channel appears, Figure 4–4, allowing you to type in directly theupper and lower limits of the scale to be displayed.
Auto Scale. This option scales the waveform currently visible in thechannel to fit it vertically to the display area: the upper limit of the scale

Figure 4–4
The Set Scale dialog
box.

Channel title

Units of channel (orleftmost visible block)

Chapter 4 — Data Display73

is set to the value of the highest peak and the lower limit to the value ofthe lowest trough. (This applies even if the signal is very small, such as
background electrical noise.)
The Scaling buttons are at the bottom left of each channel’s Amplitude
axis. Click the up button to enlarge or down button to reduce thevertical scale, halving or doubling what is shown each time.

Figure 4–5
Pointer changes in the
Amplitude axis.
Normal pointerDragging pointerStretching
pointers

The scale of the Amplitude axis can be shifted or stretched or both. This
would allow you to enlarge the signal viewed on the screen, forinstance, or move it to fit better in the display area. The pointerchanges, Figure 4–5, as it is moved over the Amplitude axis area. At
the left of the area, it is a normal, leftward-pointing arrow. To the rightof the area, though, the pointer points to the right, and a small marker
appears beside it, indicating its function. Between numbers on thescale, a double-headed arrow indicates that dragging will move thescale. If the pointer is opposite a number on the scale, two triangles
point away from the mid-point on the axis, indicating that dragging will
stretch the scale in the direction they point — and dragging in the
opposite direction will compress it (when you press the mouse button
down, the number beside the pointer is outlined by a gray box toindicate that it is the dragging point).
The Amplitude axis can be indefinitely expanded and contracted bystretching or compressing the scale, or using the Scaling buttons or the
Set Scale dialog box. Whenever the scale of a channel is altered, thenumbers for the scale in the Amplitude axis are changed to suit.
Double-clicking in the Amplitude axis area returns a shifted or stretchedscale to its normal, unstretched position, with zero at the mid-point of
the axis (the Bipolar display). Double-clicking in the Amplitude axis
area repeatedly cycles an unshifted, unstretched waveform throughSingle Sided display, Bipolar display, and Auto Scale display, in order,
from its current state.

Auto Scale All Channels
You can auto-scale the Amplitude axis in all channels simultaneously bychoosing Commands > Auto Scale Data or clicking the Auto Scale
button in the Tool bar. This scales the data currently visible in eachchannel so that the upper limit of the scale is set to the value of thehighest peak and the lower limit to the value of the lowest trough. If the74

Chart Software

Zoom window is open, the Auto Scale Data command scales the datain each channel shown there too.

Changing Channel Size
To change the size of a channel’s display, position the pointer over oneof the channel separators (anywhere along its length), so that itchanges into the separator pointer. Drag the channel separator to thedesired position — a gray line appears, to indicate where it will go —then release the mouse button. (See Figure 4–6.) You can do this while
recording, if you need to change the data display.
When a channel is thin, the title that appears in the Amplitude axis
disappears, so that only the data trace color and units are displayed.
When a channel is very thin (a quarter inch, 5 mm, or less at 72 dpi),
then there is little point displaying the data, so its data display area
appears gray (as does a channel that is turned off while recording).
Turning on or off multiple channels (by holding down the Command key
and selecting the top command from a Channel Function pop-up menu)
will turn off channels in this state, but won’t turn them on.

▼ ReferNumber of Channels,
p. 83

If you drag a channel separator past others, it will pick them up — for
instance, if you drag the separator of a channel up, you will drag up all
those of the channels above it as well (a gray line appears for eachchannel). Double-clicking a channel separator also divides the data
display area evenly into the number of visible channels.
Note that the resolution of the recorded data is independent of theresolution of the display. Unless a channel is turned off, data will be
logged in it at full fidelity during recording, even if the channel
separators have been adjusted so that the channel is very thin (with agray data display area), or not visible on the screen.

Figure 4–6
Changing a channel’ssize: drag the channel
separator until the grayline is where you want it
to be, and release themouse button.

Chapter 4 — Data Display

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Overlaying Channels
You can overlay adjacent channels in the Chart window to compare
their waveforms directly. From two to all of the channels can beoverlaid, in one or more sets. For instance, you could overlay Channels
2 and 3, and Channels 6, 7 and 8, in two separate sets.

▼ Refer
Channel Separation,p. 83

To overlay channels from the Chart window, Option-click the channel
separators between them. The channel separators vanish, and the onceseparate channels are overlaid. You can also use the Channel Settings
dialog box, which lets you both turn off channel separators to overlay
channels, and turn them on to separate the overlaid channels again(you can’t separate overlaid channels from the Chart window).
The area used by the overlay is the sum of the areas used by channels
individually. Waveforms in the data display area are kept at the sameratio of amplitude to full scale as they were individually. The channel
controls of overlaid channels are fitted into the minimum space at the
top of the channel control area at the right, and there is only one Scale
pop-up menu in common in the Amplitude axis at the left.

Figure 4–7
Overlaying channels:
top, separate; bottom,
overlaid.

The active channel, by default the top channel in a set, has its title,
scale, and so on shown in the Amplitude axis. Shifting, stretching, andscaling operations affect only the active channel. The colored square
beside the title, the same color as its data trace, helps to identify it. To
adjust a waveform’s position and scale, choose its channel from thebottom half of the Scale pop-up menu, which lists the titles of the76

Chart Software▼ Refer
Measuring from the
Waveform, p. 130

channels in the overlaid set: the chosen channel becomes the active
one. The active channel has a tick beside it.
Waveforms are drawn from the top channel first, so the lowest channel
in a set will be in front of the rest. Each waveform is tracked by a
Waveform Cursor when the pointer is over the data display area, andthe read-out shown in the Range/Amplitude display at the right.
Overlaying in the Chart and Zoom windows is independent.

Display Settings
The Display Settings dialog box lets you choose the form and units of
the Time axis, the way that Chart displays data as it records and how
and whether blocks, comments and exclusions are shown. You can also
use it to change the color and form of the graticule (the display grid) inall windows, and choose the line pattern or color of the X–Y plot.
Choose Setup > Display Settings… to open the Display Settings dialog
box.

Figure 4–8
The Display Settings
dialog box.

Chapter 4 — Data Display

77

Time Scale▼ Refer
Time Format, p. 70

The Time Scale controls let you choose the form and units of the Timeaxis. This applies to the whole axis, and can be changed at will in the
dialog box, since all time information about a recording is stored. The
time at the pointer position along the Time axis shown in the Rate/Time
display will be in the form chosen here. These controls are duplicated in
the Time Format dialog box, and changing them in either placechanges them in both.

Sampling▼ Refer
Slow and Fast Sampling
Rates, p. 37

When the Scroll Right to Left option is chosen (the default), recorded
data scroll across the data display area from the right of the Chart
window as if the display area were a roll of paper in a mechanicalchart recorder. New data are drawn at the right and old data are
moved towards the left. You don’t have to live with an old chart
recorder’s way of doing things, though. When the Sweep Mode option
is selected, data are drawn on the screen from left to right, and when
the right edge is reached, drawing starts again at the left (a vertical line
precedes the newly drawn data as they cross the screen). Data areeasier to view while being recorded if they are not moving quickly at
the same time.
At the fastest sampling rates, recorded data is drawn as if in Sweep
Mode, even if Scroll Right to Left is chosen.

DisplayLines Between Blocks. If this control is on, Chart draws a solid black
vertical line between user-defined blocks of data to indicate some formof discontinuity, such as sampling being stopped and then restarted, achannel being turned off, or sampling rate being altered. A new scaleis drawn in the channel if its range is changed. If you turn off thiscontrol, no separation line or new scale is shown between blocks. Thisis useful when you are recording for limited durations at very fastsampling rates, and so getting very short blocks.
Show Block Numbers. If this control is on, block numbers are shown at
the start of blocks as white-on-black tags in the Time axis. They mark78

Chart Software

Figure 4–9
A recording of shortsegments: left, with blocklines; right, without.

blocks even if lines and scales are not being drawn between blocks.
Turn off this control to hide them.

▼ Refer
The X–Y Window,
p. 145

X–Y Plot. The Color pop-up dialog box for the X–Y plot is identical tothose for the various channels in the Color column of the Channel
Settings dialog box, but applies only to the plot of data from one
channel against data from another in the X–Y window. There are fifteen
colors and three thicknesses; click on colors and thicknesses to selectthem. Select Join Points with Line to show a continuous data trace, or
select Show Points as Dots to show the waveform with a dot at eachsampled data point. The waveform on the right of the dialog box gives
you an idea of how the data will look.

Figure 4–10
The Color pop-up dialog
box.

Figure 4–11
The Graticule Color popup menu.

Line Graticule and Dot Graticule. Choose the Line Graticule radio button
to show a grid of dotted lines, or Dot Graticule to show a dot graticuleof the chosen color.
Graticule Color. The graticule (or display grid) chosen from theGraticule pop-up menu (see Figure 4–13) affects the Chart, Zoom, and
X–Y windows. The pop-up menu lets you choose the color of thegraticule from the fifteen colors available; choosing Off hides thegraticule. The graticule lines up with the unit divisions in the Time andAmplitude axes (divisions in the Time axis are always 20 pixels wide).

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Comments
The Comments controls cover both normal comments and exclusions, a
special category of comment. The checkboxes affect both.

▼ Refer
Printing Comments,
p. 123Show. If this control is on, comments are marked in the recording by
numbered comment boxes. They can be hidden by turning this control
off (this also inactivates the checkboxes below it). This may be useful for
printing, if you don’t want data obscured by comment boxes, lines,
areas, and text. (Comments can be printed independently from theComments & Exclusions window, if you don’t want to see them on theChart data printout.)
Draw Lines & Areas. Comments can be associated with points or areas.
If this control is on, a dotted vertical line is drawn through the point, ora light shading is applied to the area, to make location easier. Turning
this control off may again be useful for printing, if you don’t want data
obscured.

Figure 4–12
Effect of comment
checkbox settings.

All Comments
checkboxes on

Figure 4–13
The Comment andExclusion Shading popup menu.

Text Label off

Draw Lines &Areas off

All Comments
checkboxes off

Text Label. If this control is on, as much of the text of a comment as will
fit is shown vertically beside a comment line, or horizontally across anarea to the right of the comment box. The comment text appears in thechannel of a channel-specific comment, or in the top channel of one
applying to multiple channels. Vertical text dims the waveform beneathit.
Comment & Exclusion Shading. When an area rather than a point iscommented or excluded, it is marked by a shaded region. The pop-up
menus let you choose the color of the region from the fifteen light andpastel hues available (see Figure 4–13); obviously different shades
should be chosen for comments and exclusions. Choosing Off hides thecolor, but leaves areas marked with a dotted line around theirboundaries (if the Draw Lines & Areas checkbox is on).

80

Chart SoftwareChannel Settings
The Channel Settings dialog box lets you set up multiple channels
conveniently: you can both see and specify recording and display
settings for each channel in the one place. To open the dialog box,
choose Setup > Channel Settings… or type Command-Y. Note thatwhen there is no e-corder connected, a smaller version with only
display settings visible will appear. The columns in the dialog box aresummarized in the Chapter 3, and most of the recording settings are
discussed in detail. Most of the display settings are discussed in detailin this chapter.

Figure 4–14
The Channel Settings
dialog box.

Channel Titles
Normally the titles for each channel displayed at the right of the Chart
window are ‘Channel 1’, ‘Channel 2’, and so on, down from the top.
You can change the titles, if you wish, to indicate what you arerecording. To do this, select the text entry box for a channel in the Title
column of the Channel Settings dialog box, and type in a new title tooverwrite the default one. Tab down the column to select each title inturn, to change many titles at once. Text in the text entry boxes can be

Chapter 4 — Data Display

81

edited normally. If entries are left blank, the default titles (‘Channel 1’
and so on) will reappear when the dialog box is closed.
Most of the characters found in the system fonts should be available:
use Key Caps to remind you how to get unusual characters, such as Ω
(Option-Z), the degree sign, ° (Option-Shift-8), or ∆ (Option-J).

Superscripts and Subscripts
Superscripted and subscripted characters, such as those occurring in
Na+ or C2H5OH, can be used in a channel title (and unit definitions).
•••

To superscript a character or characters, type Shift-6 (^), the caretcharacter, before it or them.
To subscript a character or characters, type Option-6 (§), thesection character, before it or them.
To return to normal characters after superscripting or subscripting,type Shift-hyphen (_), the underscore character.

The caret, section, and underscore characters appear in the text entry
boxes, but not in the channel title. Ten characters at most, including
those used to superscript and so on, can be entered for a title.
Once you have changed the titles of the channels you wish to affect,
click OK to close the dialog box and apply these (and other) changes
to the Chart window. If the title is too wide to fit in the title area of the
Channel Function pop-up menu, it is truncated and an ellipsis (…)
replaces the extra characters in the display.

Color▼ Refer
Waveform Color, p. 72

82

The Color pop-up menus for the channels, in the Color column of the
Channel Settings dialog box, let you set the color and thickness of thedata trace in a channel, and whether the data points are displayedjoined by lines or as unjoined dots. Click the Color buttons to open the
Color pop-up dialog (see Figure 4–10). There are fifteen colors andthree thicknesses; click on colors and thicknesses to select them. SelectJoin Points with Line to show a continuous data trace, or select Show
Points as Dots to show the waveform with a dot at each sampled data
point. The waveform on the right of the dialog box gives you an idea of
how the data will look (see also the waveforms in Figure 4–3).

Chart Software

While the color applies to the waveform anywhere, the thickness
applies only in the Zoom window, and not in the Chart window (orOverview miniwindow for that matter), where waveforms are always
drawn as one-pixel-thick lines or single-pixel dots. For this reason, theColor pop-up menu for a channel in the Chart window is a simple
version of the one here, and does not affect the thickness of the
waveform.

Channel Separation
The Separator checkbox lets you turn a channel separator off (when it isunchecked) or on (checked). Channels that are not separated areoverlaid in the Chart window, letting you compare their waveforms
directly: the line between channels in this dialog box also disappears
when the channel separator is turned off so that the setting is easy to
see at a glance. You can overlay adjacent channels from the Chart
window (by Option-clicking the channel separators), but you can only
turn overlaying off using these checkboxes.

Figure 4–15
The Separator control in
the Channel Settings
dialog box.

Number of Channels
The Number of Channels control, at the bottom of the dialog box, lets
you choose the number of channels displayed in the Chart window.
Use the up or down arrows to increment or decrement the number, ortype a value in the text entry box directly. The control’s text entry box ishighlighted when the dialog box is first opened, so that you can quickly
change the number of channels used by Chart just by typing a number
and pressing Return or Enter.
This control both turns channels off, so that no data are recorded (justas the checkbox in the On column does), and hides them, so that thedata display area is not cluttered with channel separators. The data
display area in the Chart window is divided evenly into the number ofchannels set. The lower channels are turned off and hidden first: theirrows in the dialog box are blank and their borders grayed out. Thisfeature is very useful: not everyone needs all possible channels all the
Chapter 4 — Data Display

83

time, and it is handy to get them out of the way, and not have bunchedup channel separators using space in the data display area.

The Overview Miniwindow
The Overview miniwindow allows you to see all of a channel’s data atonce, to make locating particular events easier. It is useful for large
recordings where you don’t want to keep using the View buttons: you
can look at the data in the main Chart window at a view of 1:1, whilestill having an overview of a channel to see longer-term trends. To open
the Overview miniwindow, choose Window > Overview or typeCommand-M.

Figure 4–16
The Overview
miniwindow.
Area shown inChart window

Displayed channel

Channel Number buttons

The Overview miniwindow ‘floats’ in front of the active window, can be
moved around with its title bar, and can only be dismissed by clicking
its close button. It can be resized using the size box at its bottom rightcorner. The displayed channel can be changed by clicking the Channel
Number buttons at the bottom left of the miniwindow — theycorrespond to the numbers in the default channel titles. The number ofthe displayed channel is highlighted. Buttons for channels containing nodata are dimmed and unavailable.
The data currently displayed in the Chart window are highlighted(black on white) in the Overview miniwindow. You can scroll thecontents of the Chart window by dragging this highlighted rectangle. If
you click outside the highlighted area on a particular segment of therecording, the highlighted area is centered where you click, and theevent is also centered in the Chart window. This enables you to locate
events of interest quickly in large recordings. You can keep track ofwhere you are by shrinking the miniwindow to a small size and leaving
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Chart Software

it in an unused area of your screen. If you are using it on a huge file,the inverted area may be quite narrow: if so, drag the size box toenlarge the miniwindow and the area along with it (or use the View
buttons to increase the data shown in the Chart window).
If the data display area of the Chart window is split into two panes, thehighlighted area in the Overview miniwindow only shows the display
area of the right-hand pane. The Overview miniwindow might initiallytake a long time to draw on large files with many data points (although
it is optimized for most very large files). To interrupt its drawing, typeCommand-period: if you do this, the miniwindow will appear gray.
Click a Channel Number button or the display area to make theminiwindow draw an overview once more.

The Zoom Window▼ Refer
Selecting Data, p. 98

In the Zoom window, you can look at a small section of data in great
detail, either in one channel or in several channels over the same
period of the recording. To zoom in on a data selection, drag to selectan area of interest in the Chart window (in the Time axis for multiple
channels), and choose Window > Zoom Window or click the Zoom
Window button in the Tool bar: the Zoom window appears.
Time and amplitude readings

Figure 4–17
The Zoom window.

Overlay button
Stack button
Pointer

Waveform
Cursor
Selection
History
buttons
Marker

Chapter 4 — Data Display

ActivechannelChannel Number
buttons

Identification bars/Color popup dialog boxes

85

The Zoom window is a normal window, and can be moved around thescreen or left in the background while the Chart window is active. It
can be resized using the size box at its bottom right corner. By default,
the Overlay button is on, and if multiple channels are selected, theirwaveforms are superimposed. Waveforms are drawn from the top
channel first, so the lowest channel in a set will be in front of the rest.
Overlaying or lack of it in the Zoom window is independent of any
overlaying in the Chart window. The numbers of the Channel Number
buttons at the bottom left corner of the window correspond to channel
numbers, and buttons for channels with no selected data in the Chart
window appear dimmed.

The Stacked View
If the Stack button is clicked, then the Overlay button is turned off, andselected channels are displayed stacked one below the other in muchthe same way that they are displayed in the Chart window. The heightdevoted to each channel is in the same proportion as in the Chart
window, with channel titles and units shown at the left, or just units if
the channel is thin. Any overlaying in the Chart window is ignored.
Clicking the Overlay button turns off the Stack button and superimposeschannel waveforms again.

Figure 4–18
The Zoom window with
the Stack button on —this is the same selection
as shown in Figure
4–17.

86

Stack button
selected

Chart Software

Data Display▼ Refer
Measuring from the
Waveform, p. 130▼ Refer
Using the Marker,
p. 131▼ Refer
Color, p. 82▼ Refer
Display, p. 78

Chapter 4 — Data Display

The highlighted Channel Number button indicates the waveform that
the Waveform Cursor tracks (the active channel), whether the channels
are overlaid or stacked. The time (t) and amplitude (Y) readings at the
tracking point are indicated at the top of the window, in the forms oftime and units set using display settings and units conversion. The active
channel can be changed by clicking one of the (undimmed) numberedbuttons at the bottom left corner of the window, or clicking on adifferent waveform. In either case, the button of the selected channel
will be highlighted to indicate the channel now tracked.
The Marker from the Chart window is duplicated in the Zoom window— moving it onto a waveform in one will do the same in the other,double-clicking it will send it home, and so on. Its behaviour is alsosimilar in the Zoom window, although there is a slight difference
because the Waveform Cursor only tracks the active waveform, if there
are several. When the Marker rests on the active waveform, relative
measurements (preceded by ∆) are given in the readings for both timeand amplitude; when the Marker rests on one of the other waveforms,
the display is of relative times but absolute values.
A short bar of the color and thickness chosen for the channel waveform
is shown above the Channel Number button to aid identification. It also
doubles as a Color pop-up dialog box to let you choose settings for achannel’s data trace. It is the same as the Color pop-up menus in the
Channel Settings dialog box and for the X–Y plot in the Display Settings
dialog box (see Figure 4–10). There are fifteen colors and three
thicknesses; click on colors and thicknesses to select them. Select Join
Points with Line to show a continuous data trace, or select Show Points
as Dots to show the waveform with a dot at each sampled data point.
The waveform on the right of the dialog box gives you an idea of how
the data will look. The color applies to the channel waveform
anywhere; the thickness applies only in the Zoom window.
If the selection in the Chart window is discontinuous (straddling two or
more blocks), then the Zoom window displays a thin line to indicate ablock boundary, and a thicker line to indicate a scale change, unless
you have chosen to turn off the display of lines between blocks.

87Changing the Selection
You don’t have to return to the main window to change the selection in
the Zoom window. Instead you can move, scale, and zoom in on datafrom the Zoom window. All changes made to the selection are reflectedin the Chart window.
To zoom in further on data simply drag in the data display area tohighlight an area of interest (you cannot drag in the Zoom window’s
Time axis). When you let go the mouse button, the selection expands tofill the data display area. If channels are stacked, you can change thevertical extent of the selection in the channel in which you drag, but thefull height of the other channels is always selected. The horizontal
extent will be the same over all channels.

▼ Refer
The Amplitude Axis,
p. 73

The Amplitude axis in the Zoom window is the same as the one in theChart window, and the controls function identically. If the channels areoverlaid, then shifting, stretching, and scaling operations affect only theactive channel (except for the Auto Scale Data command, which scales
all channels), which has its title, scale, data trace color, and so on
shown in the Amplitude axis.
You can manually scroll data, as you can in the Chart window, by
holding down the Option key while the pointer is over the data display
area: this turns the pointer into a hand that can drag the data back andforth or up and down, to move the selection where you want it. (Youcannot ‘push’ the data in the Zoom window, though.)
Changes made to selections are noted, and can be recalled by the
Selection History buttons at the bottom right of the window. The up
button takes you back through the selection states, and the down button
takes you forward again. The selection history covers all states since theZoom window was last closed, including selections made in the Chart
window before the Zoom window was opened again. (It does not keep
track of whether the selection was overlaid or stacked.)

Miscellaneous
The Zoom window might take a long time if the selection has many
data points (millions). To interrupt its drawing, type Command- period:
if you do this, the data display area will appear gray. Click the display
area to make it draw the selection once more.
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Chart Software

Double-clicking in the Zoom window adds relevant data at the active
point to the Data Pad, just as it does in the Chart window: theexpansion of the waveform in the Zoom window display obviously
allows greater accuracy in selecting data points.
If you hold down the Command key when clicking a data point in theZoom window, that data point is located and centered (if possible) in
the Chart window. This is useful if you have selected a large area in theChart window to zoom in upon, so that the data in the Zoom window
ends up compressed. If you have zoomed in on a particular segment of
data, and then scrolled through the Chart window to somewhere else,then if the selection has not changed, you can Command-click in theZoom window to return to where you were.

Copying and Printing the Zoom Window
When the Zoom window is active, then the Print option in the File menuchanges to Print Zoom…, and if the command is selected, the contentsof the window are printed with the title ‘Zoom of’ and the file name.
The Zoom window can also be copied as a picture for pasting into
other applications, by choosing Copy Zoom… from the Edit menu.

Displaying Digital Read-outs
The DVM submenu of the Window menu provides a digital voltmeter foreach channel (hence the name), and read-outs of the sampling time, inthe form of resizable miniwindows. The miniwindows can let you keep
an eye on recorded values from the other side of the room, for instance.
To open one, choose a menu command from the DVM submenu, ordrag the Range/Amplitude display for a channel, or the Rate/Time
display, to tear it off.

Figure 4–19
DVM miniwindows — for
Rate/Time and Channel
1.

Chapter 4 — Data Display

Settings button

89

Click and drag here to tear off theTime miniwindow

Figure 4–20
Tearing off DVM
miniwindows.

Click and drag here to tear off achannel miniwindow

A DVM miniwindow ‘floats’ in front of the active window, and can be
moved around by dragging its border. It may be resized using the sizebox at its bottom right corner and can only be dismissed by clicking its
close button. The title bar displays ‘Time’ or the name of the channel towhich it applies. You can have one miniwindow for each channel, andanother for Time.
When sampling, the DVM miniwindow shows the current input value inthe units used for the channel. If the channel is off, the word ‘Off’
appears. When not sampling and with the pointer over the data
display area (or Time axis), the Waveform Cursor tracks the waveform,
and the DVM miniwindow displays the sample data or time values atthe Waveform Cursor position. When the miniwindow is resized, thetext also changes size for optimum fit. Thus, enlarging the window will
make the text easier to read. The text color for the Time miniwindow isblack. For channel data it is the same as the trace in the corresponding
channel.

DVM Settings
The DVM Settings dialog box (Figure 4–21) is displayed either byclicking the Settings button in a miniwindow, or by selecting Settings…
from the DVM submenu of the Window menu. The Settings dialog box
provides a means to enable or disable certain advanced features of
DVM used during sampling.

Simple Mode
With Simple selected, DVM updates its display whenever Chart has thetime to do so. This means that the updates are asynchronous, andrepresent whatever sample value happens to be present at the time
DVM requests it for display. This mode of operation has the advantage

90

Chart Software

Figure 4–21
The DVM Settings dialog
box.

of requiring minimum computational overhead, and thus does notinterfere with Chart sampling at high speeds.

Regular Updates Mode
With Regular Updates selected, DVM synchronizes itself with the data
stream and processes every sample. This makes possible simple
computations, such as data-point averaging, as well as periodic datalogging. It also adds a significant computational overhead, which may
interfere with high-speed sampling or other tasks. If this overhead turns
out to be too high, Chart will stop sampling and issue a warning.
When the Regular Updates mode of operation is chosen, data arecomputed periodically, the interval being the value entered in theUpdate Every text box. If the computer is busy, the updates may appear
at irregular intervals. If the update rate is higher than the sampling rate
in a channel, Chart will update at the lower rate. Where different
channels have different sampling rates, the channel with the highest
rate will be the one used to determine the update rate.
The horizontal arrows allow paging through the settings panels for Timeand all available channels. The settings panels are only enabled when

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91

the Regular Updates mode is selected. Since they don’t apply, some ofthe settings panel items for Time are always grayed out.
In the Regular Updates mode of operation, new display options also
become available. In addition to the default display, Digital Only, theuser may select to display either a Bar Graph or an Arrow Indicator. It
is also possible to keep a History of recent data points, which is a selfscaling graph of those points. The number of points displayed in thegraph depends on the time value entered in the Keep text box.
The values displayed and/or logged may be the Value of the last
sample in the interval, or the Average, Maximum, or Minimum valuesof all the samples in the last interval.
If the Log to DVM Window check box is selected, the data will be
logged to the DVM Log window, in the column entered in the text box.
Upon starting each sampling run, and to aid with the identification of
the columns, the title ‘Time’ or the name of the corresponding channel
will also be displayed in the same column. The DVM Log window canbe displayed by selecting it from the Window menu.
The data in the window may be copied to the clipboard and pasted
into other applications, such as word processors and spreadsheets.
They can also be saved to disk as a text file. If more than one channel
is set to display in a given column, the numbers from the highernumbered channel are displayed.

The DVM Log Window
The DVM Log window can be used for the periodic logging of data,
which can then be exported to other applications for further processing,or saved to disk as a text file. It is opened by selecting DVM Log
Window from Chart’ s Window menu, and only works when Regular
Updates mode has been selected in the DVM Settings dialog box.
Logged data are displayed in the window as columns. The appearanceof these columns is controlled by the DVM Log Window Settings dialog
box, which is displayed by clicking the Settings… button at the top of
the DVM Log window. Font types and sizes, as well as the column
width, can be adjusted by clicking on the Display… button.

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Chart Software

Figure 4–22
The DVM Log window.

Clicking the Copy button places a copy of the entire content of the
DVM Log window on the clipboard. Clicking the Clear button
permanently deletes all logged data.

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93

94

Chart SoftwareC H A P T E R

F I V E

5 Working With Files
Chart files can be easily accessed with the Experiments Gallery, andcan be edited, printed, and saved to disk in various formats. This
chapter describes these operations, and such features as creating asingle file summarizing results from many files, and saving settings toallow easy repetition of an experiment. Other topics covered include
the transfer of data to other applications, the use of comments andexclusions, and the Notebook, and finding particular Chart files
quickly.

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The Experiments Gallery
The Experiments Gallery is a framework that provides easy access toChart data and settings files, as well as any related material such as
documentation, text files or multimedia files.
It is particularly useful in a teaching environment as it allows teachers toorganize files for different experiments and make them easily accessible
to students. If you are a researcher you will also find it useful fororganizing and getting easy access to your recordings.

Using the Experiments Gallery
Before you can use the Experiments Gallery, it must have been created
and files or folders must have been added. This may have already been
done in your version of Chart, but if not, see Managing the Experiments
Gallery, p. 97.
Once the Experiments Gallery is in place, the Experiments Gallery
dialog box will be displayed when you choose Experiments Gallery…
from the File menu. If you select the Show at startup checkbox at thebottom of the dialog box, it will also be displayed when:•

You start Chart without a document (for example, when you doubleclick the Chart desktop shortcut•

You close the last open Chart document.

The left-hand pane of the dialog box contains a folder hierarchy of theExperiments Gallery contents. It is similar to the Macintosh Finder and isnavigated in the same way, clicking on the disclosure triangles toexpand branches of the folder structure, for example. In the right-handpane are shown the files in the folder selected in the left-hand pane.
The selected file is indicated by shading, and can be opened byclicking the Open button. Alternatively you can double-click files toopen them.
Depending on how the Experiments Gallery has been set up, there may
be an information area above the file list (as shown in Figure 5–1),
containing comments about the contents of the selected folders.

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Chart Software

Figure 5–1
The Experiments Gallery
dialog box.

Individual files may also have labels describing them, in addition totheir file name.

Managing the Experiments Gallery
If you are a teacher or a researcher, you will probably want to create
an Experiments Gallery tailored to your own needs.
First, create a folder called ‘Experiments Gallery’ in the same folder as
the Chart Application (Figure 5–2). Note that this folder may alreadyexist, depending on your version of Chart.

Figure 5–2
Creating the Experiments
Gallery folder.

Chapter 5 — Working With Files97Add folders and files to the Experiments Gallery folder you havecreated (if there are no folders or files in the Experiments Gallery folder,
the Experiments Gallery dialog box won’t appear in Chart). You canorganize the folders and files in a manner which suits the structure ofyour experiments. You can add shortcuts as well as files, to give accessto files stored on a network, for example. Remember that it can be
useful to add documentation, text files, multimedia files and so on to theGallery. The folders and files will be displayed with the same hierarchyin the Experiments Gallery dialog box.
To delete the Experiments Gallery, and stop the dialog box fromappearing in Chart, either remove all the folders and files from theExperiments Gallery folder, or delete the Experiments Gallery folder
entirely.
▼ Refer
Experiments Gallery
Configuration Files,
p. 263You can control the way the files in a folder contained in theExperiments Gallery appear by creating a ‘configuration file’ andincluding it in the folder. Details on creating configuration files, with an
example, can be found in Appendix D.

Selecting Data

Figure 5–3
An active point (top) anda selection rectangle in achannel of the Chart
window.

If you click in the Time axis, a blinking vertical line indicates the active
point over all channels; if you click in a channel, the blinking line andactive point are confined to one channel (Figure 5–3, top). An active
point is distinct from a selected area, and is used for adding comments,
transferring information to the Data Pad, and so on. Although you cancopy a single data point to the Data Pad, you cannot copy it to the
Clipboard, save it as a file, or zoom in on it.
To select an area of data in one channel, position the pointer and dragto highlight a rectangular area (Figure 5–3, bottom). Shift-click toextend the selection in the channel. The extent of vertical selection
affects display in the Zoom and X–Y windows, but will not affecttransfer of information to the Data Pad, printing the selection, or saving
the selection as a file: these operations will use the full array of data
points over the recording period of the selection. Command-drag toselect the full height of a channel.
To add channels to a selection, hold down the Shift key and drag in thedisplay area of the channels you want: the vertical extent of the98

Chart Software

selected rectangle in other channels can be varied, but the horizontal
extent will be the same as that in the first selected channel. (Therecording period over which selections are made in multiple channels
must always be the same.) Command-Shift-click in the display area of achannel you want to add to select its full height. Option-Shift-click to
select the same relative area of an added channel as in the firstchannel. This area takes into account any stretching or scaling of achannel’s Amplitude axis, making direct comparison of waveforms
overlaid in the Zoom window easy. It only deals with the recorded
data, though, and ignores any scaling due to units conversion.

Figure 5–4
Selecting data in multiple
channels: left, from theTime axis; right, Shiftdragging in the channel
you want to add.

To select an area of data in all channels, position the pointer in theTime axis area: the pointer will change to a double-headed arrow.
Drag in the Time axis area to highlight a rectangular area over all
channels: Shift-click along the Time axis to extend the selection from thepoint at which you started to drag. Shift-click in the display area of achannel to deselect it. Double-clicking in the Time axis selects an entire
block of recorded data (the whole file, if it is continuous).
If two or more channels are overlaid, simply drag to create a common
selection rectangle over both channels. If you overlay separate channels
with existing selections in one or more of them, you should reselect thearea to ensure a common selection rectangle.
Finally, you can select all data in the Chart window by choosing SelectAll from the Edit menu, or typing Command-A.
When there is a selection in the data display area, some of the menu
commands available change to reflect this. In the File menu, the basic

Chapter 5 — Working With Files99

Print command changes to Print Selection…, and Save Selection…
becomes undimmed. In the Edit menu, Copy Selection… and Delete
Selection become active as well.

Deleting Data
There are two sorts of data deletion available when the Chart window
is active: you can clear a selected area of data for all channels, or you
can clear all of the data recorded in a particular channel. (You cannot
just delete an area of data in one channel.) These operations cannot be
undone, so alert boxes ask you to confirm your decisions. If you do
accidentally delete vital data, and you have saved the file previously,
you should immediately close the file without saving the changes — thefile will revert to the last version saved. You may lose some changes,
but the data just deleted will be there on reopening the file. (Frequentsaves and backups are, of course, always good practice.)▼ Refer
Display, p. 78

To delete an area of data common to all channels, drag along the Timeaxis to select the area corresponding to the period between two points
on the axis. This would be useful to delete stretches of a recording
where nothing particularly interesting occurred. Choose Edit > Clear
Selection, or press the Delete key. In fact, if there is any selection in theChart window in one or more channels, then these actions will clear thedata block from all channels, subject to confirmation through the alert
box. Since you create a discontinuity in the record by deleting dataover a specified period, a new block is defined. It is marked by a solid
vertical line, unless display settings are otherwise set up. (If there is only
an active point rather than a selection in the Chart window, thenpressing the Delete key does nothing and the Clear Selection commandis dimmed.)
To delete all data from a particular channel, make a selection in thatchannel (an active point will do), and choose Edit > Clear Channel… toclear all data from a particular channel. An alert box will ask you to
confirm the deletion.

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Transferring Data
▼ Refer
Saving Options,p. 104It may be useful at times to transfer data from Chart to otherapplications, such as a spreadsheet or drawing program. A file, aselection, or the contents of the Data Pad can be saved as a standard
text file able to be opened by any application that can import text, suchas a word processor, spreadsheet, or statistics package. (Choose File >Save As… to do this.)
You can copy selected data from Chart and paste the data directly intoanother application. The Copy command in the Edit menu changes toshow available options when different windows are active, or under
different conditions. If the Data Pad is the active window, then you cancopy all of it, or selected rows, to the Clipboard as text. (The menu
command will be Copy, Copy All, or Copy Selection, depending on
what is selected.) If either the Zoom or X–Y window is active, then the
Copy command changes to Copy Zoom… or Copy X–Y… respectively.
These two commands copy the contents of the window to the Clipboard
as a QuickDraw picture. When chosen, the Copy as Picture dialog box
appears (with the name of the window in its title).

Figure 5–5
The Copy as Picture
dialog box.

There are three options for picture resolution when copying a picture: ineach case, a QuickDraw PICT is created at the specified resolution.
Screen copies the contents of the window at 72 dots per inch, theostensible screen resolution, so the picture you see on the monitor isexactly what is pasted into another program. Expanded copies the
picture at four times the visible size: when pasted into a program thatcan scale it, it can have an effective resolution of 288 dpi. High createsa 300 dpi picture, the same resolution as an older laser printer.
Click a radio button to choose the option appropriate to the program
where you intend to paste the picture. A drawing application would

Chapter 5 — Working With Files101

handle a high-resolution picture, and you could use the extra features
available to modify it for a report or for display. Some programs might
convert PICTs into bitmaps. The Expanded resolution option lets you
create a picture that if converted to a bitmap and scaled to a quarter of
its size, prints nearly as well as a high-resolution picture.

Copying a Selection
If the Chart window is active and you select an area of data, choose
Edit > Copy Selection… to copy the data as text: the Copy to
Clipboard dialog box appears.

Figure 5–6
The Copy to Clipboard
dialog box.

Channels. The Channel Number buttons let you choose the channels to
be saved (and correspond to the numbers in the default channel titles).
Those buttons whose channels have no data or are not selected will bedimmed. Highlighted buttons indicate the channels to be included in the
text (by default, all selected ones with data). Click the buttons to selector deselect channels. Channel data will appear as columns in the text,
in numerical order, left to right, separated by tabs.

▼ Refer
Time Scale, p. 70

102

Time. When the Time checkbox is selected, then the time at which eachsample was taken is listed in addition to the data points themselves,
preceding the channel data (as the first column of text). The time format
can be chosen using the controls at the right of the dialog box. The
options are the same as those for display settings.

Chart Software

Comments. When the Comments checkbox is selected, comments atany data point are included as the last column in the text. If there areno comments in the file or selection, this option will be dimmed. If theComments checkbox is the only thing selected, a numbered list ofcomments is copied. (Exclusion comments are ignored.)
Settings Info. If the Settings Info checkbox is selected, then sampling
rates, ranges, units conversion information, and recording dates andtimes are noted as data header lines for every block of data in the text.
Channel titles are also included, but other Chart display settings are
ignored. This information allows Chart (using a Chart extension, Read
Text) to reconstruct a Chart file from a text file, and match the originalChart file exactly. It is useful for transferring files between versions ofChart, retrieving files archived as text, and so on.
Reduction. By default, the text includes a data point for every sample in
the file. You might not want all this detail, say, if you have recorded
something at a high sampling rate, and there are too many data points
for your graphing application to cope with. By entering a number otherthan 1 (the default) in the Reduction box, you can use fewer samples. If
you enter 2, the text would include the data points for every second
sample, if you enter 3, the text would include those for every thirdsample, and so on. Comments are not lost, even if the particular data
points they were attached to are not included.
▼ Refer
Using Exclusions, p. 123

Exclusions (points or areas marked as excluded from analysis) aretreated as separate blocks containing no valid data, and are notcopied to the text. Exclusion comment text is also ignored.

The Clipboard
Whenever you cut or copy data from Chart, the information is stored
on the Clipboard. Choose Edit > Show Clipboard to see what has been
copied: the Clipboard window appears. It is a normal window and canbe moved around the screen or left in the background while the Chart
window is active. The Clipboard window can show a representation ofa picture (sized to fit the window), or in text format, data from the Chart
window or Data Pad.
If a large selection is made, then during copying a progress indicatorand the percentage of the file currently copied as text are shown in the

Chapter 5 — Working With Files

103

Figure 5–7
The Clipboard window
after copying: left, Chart
window/Data Pad; right,
Zoom window.

text box of the Tool bar (if it is visible), just as occurs with a file being
saved as text. To stop the process, type Command-period.

Saving Options
To save a file of recorded data, choose File > Save, type Command-S,
or click the Save button in the Tool bar. When this is done, an existing
file will have any changes made to it saved to disk. The first time thatyou save a file, or whenever you choose File > Save As…, the Save As
dialog box appears.

Figure 5–8
The Save As dialog box(see the Macintosh
system help for the many
shortcuts available).

Choose a file type
here

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The dialog box lets you navigate through the filing system of thecomputer to choose where your file will be saved. Once you choose afile format from the Format pop-up menu, and enter a name for the file,
you can then save the file by clicking the Save button. The main formats
are data file, settings file, text file and Chart for Windows data file. You
can also save the contents of the Data Pad, Spectrum window or DVM
Log window as a text file. Other formats can be added by Chart
extensions. You can save multiple copies of a file in any format orformats, if the copies have different names or are in different places.

Data File
The data file format, the default, saves both data and settings (including
macros). The file includes the entire recording, and is the usual way tosave data. Since Chart lets you have open only one data file at a time,
opening or creating another means you must close any currently open
file. If such a file has any unsaved changes, an alert box informs you
and lets you save or discard them, or cancel.

Settings File
The settings file format does not save any recorded data, but stores thecurrent settings. These include those that affect recording, such as the
sampling rate, channel ranges, triggering, and stimulation settings, andthose that affect the way the data looks, such as the window size,
channel areas, display settings, and menus. Macros are also stored as
settings. Using settings files, you can build up a library of settings formany different experiments, to enable quick and easy preparation forrecording.
Opening a settings file, if no Chart file is open, creates a new untitleddata file with the defined settings. If an existing Chart data file is open,
then an alert box gives you the choice of creating a new untitled data
file with those settings, or applying the settings to the current Chart file.
Applying settings to a file affects the display of existing data and therecording settings for subsequent sampling. It does not affect therecording settings of, or alter, existing data: sampling rates, ranges,
applied units, and so on are all left unchanged.

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105

Text File
This format saves data as a standard text file able to be opened by any
application that can import text, such as a spreadsheet, word
processor, or statistics package. Each sample recorded is stored as arow of data readings for each channel, separated by tabs and ending
in a return character (that is, taking up a single line). If you opt to savea Chart file as a text file, the Save As Text File dialog box appears
when you click Save. It is much the same as the Copy to Clipboard
dialog box (see Copying a Selection, p. 102, for details).

Figure 5–9
The Save As Text Filedialog box.

The size of a text file is much greater than the size of the Chart data filefrom which it is created. While a file is being saved as text, the text boxof the Tool bar (if it is visible) shows a progress indicator and thepercentage of the file currently saved. Type Command-period to stop
the process: you get a text file with as much data as had been dealt
with at the time you stop.
Chart allows you to record files with different sampling rates on
different channels. If you save such a file as a text file, Chart will
determine the smallest sampling interval (highest sampling rate) used
and will include data points separated by that interval for all channels.
For the channels that have longer sampling intervals, the extra data
values are generated by linear interpolation. For example, if you had
recorded on Channel 1 at 1000 /s, on Channel 2 at 200 /s and on
Channel 3 at 100 /s, the text file would include data values separated
by 0.001 s, for all three channels. In the case of Channel 2, every fifth
data value included in the file would be ‘real’, with four interpolated‘pseudo’ values in between. With Channel 3, every tenth data value
would be ‘real’ and there would be nine interpolated values between.

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Chart for Windows Data File
This format saves a file as a data file that can be read by Chart v4.2
for Windows or later. Choose Chart (Win) Data in the Format pop-up
menu: the ‘.edcht’ suffix will be appended to the name. Windows
needs this to identify the file type. The data and channel titles areexported. The settings for range, computed input, units conversion andmacros are not exported and need to be redefined if they are required
for new data. Most display settings, such as data trace colors, channelheights, and so on are ignored.
If you save a Chart file containing calculated data, a dialog box
appears that lets you choose to save the calculated data, or just theunderlying recorded data.

Figure 5–10
The Translation Options
dialog box.

Note that the Chart for Windows program reads all the data in an
exported file as recorded data — only the result of a calculation issaved, not the settings that generated the calculated data. For thisreason, if the calculation can be applied in Chart for Windows,
exporting the data and then applying the calculation in Chart for
Windows is preferable to applying the calculation in Chart for
Macintosh and then exporting.
Exclusions are treated as normal comments. Excluded data are treatedas valid, so they are included in the export. Commented and excluded
areas become commented points in Chart for Windows, positioned at
the start time of the area. If the extent of an area in a Chart for
Macintosh data file is important for the translation, it should be noted in
the comment text.

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Data Pad, Spectrum and DVM Log Window Text Files▼ Refer
The Data Pad, p. 136
The Spectrum Window,
p. 147
The DVM Log Window,
p. 92

The contents of the Data Pad, Spectrum window and DVM Log Window
can be saved as standard text files able to be opened by any
application that can import text, such as a word processor,
spreadsheet, or statistics package.
Data Pad text file. To save the Data Pad contents as a text file, choose
Text – Data Pad from the Format pop-up menu in the Save As dialog
box. Each row in the Data Pad becomes a line in the text file, with thecontents of the column cells in the row separated by tabs. Empty
columns are not included in the file. Titles can be added to the top ofeach column by using the Data Pad’s Add Titles command prior toadding the data.
Spectrum text file. To save the Spectrum window contents as a text file,choose Spectrum Text from the Format pop-up menu in the Save As
dialog box. The text file contains two columns separated by tabs, one
column for frequency and one column for the height of the spectrum atthat frequency.
DVM Log window text file. To save the DVM Log window contents as atext file, choose DVM Log Window from the Format pop-up menu in the
Save As dialog box. The text file contains columns for each channel
that has been set up to log to the DVM Log window, and one for time
too, if it is being logged.

Auto Save
Choose File > Auto Save… to set up Chart to automatically save whilesampling (you need to do this before you start sampling). The Auto
Save dialog box appears (Figure 5–11).
Select the Auto Save while sampling checkbox to turn on automaticsaving. You can choose the period between saves, from one to 1000 inunits of minutes or hours. Choosing the Append to current file option
simply means that your data will be saved to the same file each time an
autosave runs. Choosing the Use new file each time option means thatyour data is saved to a new file each time an autosave runs, with files
named file(001), file(002), and so on, where file is the name of yourChart file. This is useful for breaking up a very large file into smaller

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Chart Software

Figure 5–11
The Auto Save dialog
box.

pieces, to reduce the risk of losing everything in case of file corruption.
You can also specify whether you want a save to occur when samplingstops. Note that Chart stops sampling while the save occurs, so bear
this in mind when setting the autosave period and mode.

Saving a Selection
You can choose to save a selected area of data instead of the whole
file, letting you extract and place into a new file only the part of therecording that you need. You can save the data between any two
points on the Time axis for any combination of channels. If there is aselection in the Chart window, then File> Save Selection… is available;
otherwise it is dimmed and cannot be chosen. Choose the command toopen the Save Selection dialog box.

▼ Refer
Saving Options, p. 104

This dialog box is similar to the Save As dialog box, except that you
have a choice of only two file formats from the Format pop-up menu,
data file and text file: the other options are dimmed and unavailable.
Once you choose a file format from the Format pop-up menu, and entera name for the file, you can save the file by clicking the Save button.
Saving a selection does not save the contents of the Data Pad. If you
save the selection as a text file, the Save As Text File dialog box
appears when you click Save (Figure 5–9). If there are any commentsin the file, the Comments checkbox there will not be enabled. If,
however, none are in the selection, a created text file will have tabs atthe end of each line (since these would have preceded any recorded
comments), unless the checkbox is turned off. In conjunction with the
Append feature, you could use the ability to save a selection for quick

Chapter 5 — Working With Files

109

Figure 5–12
The Save Selection
dialog box.

creation of new files containing summarized results from much larger
recordings.

Appending Files
This feature allows any Chart file to be appended to the end of an open
Chart data file in order to produce a single file with the desired
contents. By combining this feature with Chart’s ability to save
selections of data as files, summary files can be created using only
those recording segments that have significance. Choose File >Append… to append a file to an open data file. The Append dialog
box will appear.
The Format pop-up menu lets you choose the sort of file to open: only
the chosen types will be visible in the scrolling list. Chart files areusually the only choice available, but others may be added throughChart extensions. Select the file to append to the currently open file andclick the Open button to append it. All comments will be copied acrossand renumbered, following on after the last comment in the original file.
Settings from the appended file are not copied across, so the Discard
Existing Macros checkbox is dimmed and unavailable. Recording
settings such as channel ranges and sampling rate will be the same forsubsequent recording as they were prior to appending the file. Eachappended file is treated as a new user-defined block or set of blocks.
The appended file’s Data Pad is appended to the current file’s Data
Pad (so it helps if you have titles to separate the data sets). You can
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Chart Software

Figure 5–13
The Append dialog box.

append files to the currently open file as long as there is enoughmemory to perform the operation.
Appending a settings file is the same as opening one with an existing
Chart data file open. An alert box gives you the choice of creating a
new untitled data file with those settings, or applying the settings to thecurrent Chart file. Applying settings to a file affects the display of
existing data and the recording settings for subsequent sampling. It
does not affect the recording settings of, or alter, existing data:
sampling rates, ranges, applied units, and so on are all left unchanged.

Printing
Printing a Chart file or part of it gives you a hard copy of data for use
in write-ups of experiments, reports, presentations, and so on. There are
two menu commands in the File menu to do with printing: Page Setup…
and the basic Print command (with a keyboard shortcut of Command-P),
which changes depending on what can be printed.

Page Setup
To print, you need to set up the document correctly for the printer being
used. Choose File > Page Setup… to open the Page Setup dialog box:

Chapter 5 — Working With Files111

its appearance depends on your printer and software (the printerdriver). The documentation that came with your printer and computer
should explain most of what is involved. Select the paper size that you
will print on (A4, Letter, and the like), page orientation (portrait orlandscape), and so on. Chart has its own specific options in the dialog
box: choose Chart from the pop-up menu to set them (Figure 5–14).

Figure 5–14
Chart’s Page Setup
options.

High-Resolution Printing
Selecting this option allows you to print the Chart, Zoom or X–Y
windows at the maximum resolution of the selected printer. If you areusing a 600-dpi laser printer, Chart will print with a resolution of 600
dots per inch. This will result in print of the best quality, but, since every
data point and connecting line is drawn at full resolution, printing may
be quite slow, especially for the Chart window.
Without high-resolution printing, the drawing resolution is limited to thenominal resolution of the computer screen (around 72 dots per inch).
This is, however, adequate for drafts and overviews, and will result inquicker printing — especially for overviews where the file ishorizontally compressed, since a lot of data must otherwise be drawn
unnecessarily. If your computer and printer are slow, we recommendthat in most cases you use high resolution only for the final copy.

Print Using Color▼ Refer
Display Settings, p. 77

112

Selecting this option enables color printing of your data. You can set up
data display colors using the Display Settings dialog box. Some colors
may not be supported by certain color printers, or the colors actually
printed may differ from those that appear on a color monitor. Try a few

Chart Software

samples with your setup to establish color compatibility. Colors will
print as grays on a grayscale printer.

The Print Command
If the Trigger, Stimulator, or Clipboard windows are active, the Print
command is dimmed and cannot be chosen. In other circumstances,though, the command will be available and will appear in various
forms depending on which window is active and whether any selection
has been made (Table 5–1). Clicking the Print button in the Tool bar isin all ways equivalent to choosing the basic Print command.

Table 5–1
Printing commands.

Print Command

Active Window

What Prints

Print All…

Chart

The whole file

Print Selection…

Chart

The selected area

Print Zoom…

Zoom

Zoom window contents

Print X–Y…

X–Y

X–Y window contents

Print Comments…

Comments & Exclusions

List of comments infile

Print Data Pad…

Data Pad

Data Pad contents

Print Notebook…

Notebook

Notebook contents

Print Spectrum…

Spectrum

Spectrum window
contents

Print All… can print the whole Chart file. When using a compatible
continuous-feed printer, this provides a continuous record just like thatobtained from a mechanical chart recorder. You can specify a more
limited printing range in the Print dialog box provided by the operating
system, but it is better to select the data you want printed. Print
Selection… prints the selected area or areas in the Chart window. If
there is no selected area in the Chart window (only an active point,say), then Print All… is the available command. If you have used theView buttons to compress a file horizontally (up to 2000:1), then thefile or selection will print at the chosen compression.
When printing the contents of the Zoom, X–Y or Spectrum windows, thePage Layout dialog box lets you adjust the size and location of theimage. The shaded rectangle shows the dimensions and orientation of
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113

image to reposition it on the page (the gray border shows where it willgo), and drag the gray box at the bottom right of the image to adjust its
size. You can double-click the image to scale it to the maximum sizethat will fit on the page. With the Zoom and X–Y windows, the Keep
Shape checkbox is present in the Page Layout dialog box. If this is
deselected, then the image can be reshaped at will. Otherwise theimage is scaled in proportion to its original dimensions (which arethose of the Zoom or X–Y window) or the dimensions set when the
checkbox was off.

Figure 5–15
The Page Layout dialog
box.

Picture size and pageorientation

Turn off this checkbox toreshape the image

The Data Pad and Spectrum windows are printed out looking much likethey do on screen, except that empty columns are not included in the
Data Pad printout. The Notebook pages are also printed out much as
they appear on screen (Chart will not print empty Notebook pages).
The Print dialog box that appears when you select the Print command
will depend on your printer and software (the printer driver). The Print
dialog box lets you select a page range when you choose the Print
All… command, but Chart works out the page breaks as it prints, so
you may not get what you want. It is better to select the data to print
and print that selection.

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When printing the contents of the Chart, Zoom or X–Y windows, Chart
includes a footer on each page consisting of a separating line, beneath
which are the date and time of printing, the computer owner’s name if
it is in the system already (for file sharing), and the page number of theprinted page. If the file has been saved, its title appears at the top of
the first page. The Marker is drawn if visible, but the pointer andWaveform Cursors are not. When printing a selection or the first pageof a file, channel titles and units are included at the left of the print-out,and the ranges of the channels are also drawn, much as things appear
in the Chart window. The date and time at the start of each block isshown along the top of the print-out, where the block is wide enough.
When printing the Spectrum window, Chart includes a title containing
the file name and channel from which the selection was taken.
Information on the data selection (start time and duration) and calculation
shown in the Spectrum window are also noted.

The Notebook
The Notebook is like a laboratory notebook attached to (and saved
along with) a Chart file. It can be used to explain experiment protocols,
macros, and expectations. It lets you make general notes about therecording as a whole, in contrast to comments, which are meant forbrief information specific to a particular time, channel, or data
selection. To use the Notebook, choose Window > Notebook. The
Notebook window appears. It is a normal window, and can be used
and moved while sampling, or left in the background while the Chart
window is active.
The Notebook has a total of eight numbered pages that can be used forjotting down general notes about a file. Each page can contain up to
32 000 characters, and you can autoscroll vertically through thecontents using the up and down arrow keys on your keyboard. (Only
about the first 1200 characters will print if the Notebook is printed,
though: transfer the text to a word processor if this is a problem.)
Clicking the ‘dog-ears’ at the lower left of the window turns the pages
back and forth. Click the Date or Time buttons at the bottom of thewindow to add the date or time to your notes at the insertion point (inthe format set for your computer in the Date & Time control panel). The
commands Cut, Copy, Paste, and Clear can be used to edit text
normally, although you cannot paste graphics into the Notebook.

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115

Figure 5–16
The Notebook window.

Write yournotes here

Click here to
move to next
page
Click here
to moveback apage▼ Refer
Appending Files, p. 110

Click here to
add the date

Click here to
add the time

The contents of the Notebook window are saved with both Chart data
and Chart settings files. However, if you append a settings filecontaining Notebook information to a data file that also contains
Notebook information, the data file’s Notebook contents will not be
replaced.

Printing the Notebook
When the Notebook window is active, then the Print option in the Filemenu changes to Print Notebook…, and if the command is selected, thecontents of this window are printed rather than those of the Chart
window. The Print dialog box allows you to print the contents of the
Notebook, or any selected page range (Chart will not print empty
Notebook pages). The pages are printed out as they appear on screen,
stretched to fit the text to some extent, but text in excess of 1200
characters or so will be truncated. You can copy the contents of the
Notebook, page by page, to the Clipboard for pasting into a word
processor if you want to use the text elsewhere.

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Comments and Exclusions
Comments are normally used to note brief information specific to aparticular time, channel, or data selection. (You can make moregeneral and extensive comments about the recording as a whole in the
Notebook.)
Comments let you annotate your recording, marking times, points, andareas of interest. They provide a quick and accurate method of locating
specific data and times in a file. Exclusions are a special category ofcomment marking points and areas to be excluded from data searches,
Data Pad calculations, saving as text, and so on. The mechanics ofadding, viewing, and editing comments and exclusions are much thesame, but the effects are different: comments merely mark a point orarea, but exclusions can change the way a point or area is treated. The
discussion here applies to both categories unless otherwise indicated.

Using the Comments Bar
The Comments bar is used to add comments to single data points while
recording (it does not appear when Chart is not sampling). It cannot
add exclusions or comment upon areas, but is useful for quickly noting
events as they occur. Type in the text entry area at the bottom of theChart window, and press the Enter or Return key to add the comment to
the file at the time the key is pressed.
By default, the comment applies for all channels, and the numberedcomment box is preceded by an asterisk. To comment on a specificchannel, select the asterisk by clicking it or pressing the Tab key, andtype the number of the channel, or click the channel in the data display
area: the channel number appears (for Channels 1 to 8; you can’t
make a specific comment for 9 to 16 here while recording). To apply acomment to all channels, select the comment channel number and typea character other than 1 to 8, or click the gray area at the bottom of
the Chart window (the Time axis area when not sampling).

Figure 5–17
Comment entry during
recording.

Channel the comment
applies to (* for all)

Chapter 5 — Working With Files

Comment
number box

You can add yourcomment text here117

▼ Refer
Automatic Comments,
p. 226The Automatic Comments feature lets you add predefined comments
while recording, at the press of a Function key. These are also single
commented points, not areas or exclusions. These comments areentered in the Automatic Comments dialog box. (You could also just hit
the Return key and edit the comment later, if you are unprepared.)

Adding Comments to Recorded Data
Comments and exclusions can be added to existing data once it has
been recorded. (This can be done while sampling if the Chart windowis split and recorded data are selected in the left-hand pane.) First
ensure there is a suitable active point or area selected. To add acomment, choose Commands > Add Comment…, type Command-K, or
click the New Comment button in the Tool bar. The Add Comment
dialog box appears. To add an exclusion, choose Commands > Add
Exclusion… or type Command-E. The Add Exclusion dialog box
appears.

Figure 5–18
The Add Comment and
Add Exclusion dialog
boxes.

A comment can be typed or pasted into the Comment text entry box.
For practical purposes, the text should not exceed 60 to 70 characters,
since more than that will neither be clearly visible in the pop-up
comment box nor print in full when a list of comments is printed.
You may choose at the outset to apply the comment to all channels, a
specific channel, or a set of channels, by clicking or making a suitableselection in the Time axis area or the channel of interest. When the118

Chart Softwaredialog box appears, the Channels text entry box shows your initial
selection, but you can change it. Enter ‘All’ for all channels (1–16), or
the numbers of channels to be affected, in one or more sets. Spaces are
ignored, commas separate, and hyphens indicate a range, so entering‘2, 4, 6–8’ would apply the comment to Channels 2, 4, 6, 7 and 8.
You can apply a comment to a channel currently hidden or off.
Click OK, or press the Enter or Return key, to add the comment to thefile at the active point or over the selected area, in the chosen channels.
If Chart cannot make sense of an entry (if a channel number was over
16, say), it will instead apply the comment to your initial selection.

Appearance▼ Refer
Display Settings, p. 77

The appearance of comments in the Chart and Zoom windows is set in
the Display Settings dialog box. They can be hidden altogether, shownas numbered boxes, marked by dotted lines or areas of a chosen
shade, and may have the comment text visible as well.
Comments are automatically numbered in the order in which they areadded to a file, regardless of category (comment or exclusion), and notnecessarily left to right across a file. Numbered comment boxes areshown in the Time axis for comments applying to all channels, in thechannel of a channel-specific comment, or in the top channel of acomment applying to several channels. The boxes are filled with theshade assigned to the comment category.
Commented points are marked by a dotted vertical line, and areas aremarked by a chosen shade (comments use a solid shade; exclusions
are striped). Comments apply to a time or time range, so they always
mark the full height of the channel or channels to which they apply. Asmuch of the comment text as will fit is shown vertically beside acomment line, or horizontally across an area to the right of thecomment box. The text appears in the channel of a channel-specificcomment, or in the top channel of one applying to multiple channels.
Vertical text dims the waveform or block boundary beneath it.
Text labels are obviously very useful, since one can immediately read
what the comment or exclusion marks, if the text is brief. If the commentis too long to be seen in the space available, you can read it bypositioning the pointer over the comment box and pressing the mousebutton (Figure 5–19). As well as the text of the comment, the pop-up

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Figure 5–19
General and channelspecific commented andexcluded points andareas, and the pop-up
comment box.

comment box shows its number, category, and time or time range. A
comment read like this in the Chart window is highlighted in theComments & Exclusions window, and scrolled to if it is not visible, if
that window is open.

Changing Times
Comments can be edited in various ways. Changing the time or time
range is done in the Chart window. To do this, click the comment box
for the comment to be changed. A commented point will show a single
control handle (a black box) at the top of its dotted line and an area
will show three control handles at the top of its area. The control
handles still appear even if lines and areas are not displayed. Drag the(middle) control handle to move the comment. Drag the outer control
handles of an area to increase or decrease the area’s extent, andhence the comment’s time range. A highlighted line or area showswhere things will end up when you release the mouse button. You can’t
move or extend comments beyond a block boundary. If you need finer
control of comment position, use the Zoom window to look at aselection in more detail: comments are duplicated there, and can moreeasily be assigned to particular data points or areas.

Figure 5–20
Changing a comment’s
time (left), and time
range (right) in the Chart
window.
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The Comments & Exclusions Window
The Comments & Exclusions window lets you look at comments in thefile together, locate or delete them, or edit their text. To use thewindow, choose Window > Comments & Exclusions or type CommandL. The Comments & Exclusions window can be moved around thescreen or left in the background while the Chart window is active.
ChannelNumberbuttons

Figure 5–21
The Comments &Exclusions window.

Commenttext
If text is entered
here, only
comments
containing thattext will be listed

The comments are listed down a scrolling field in the order that they
appear left to right across a file (and so not necessarily in numericalorder). The comment numbers appear in boxes, as they do in the Chart
window, with the box preceded by the number of a specific channel itapplies to, or an asterisk if it applies to more than one channel. The
category of the comment (comment or exclusion) is listed at the right.
Use the scroll bar to the right of the window to go through long lists ofcomments.
A number of features in this window help in searching large files forcomments by restricting which comments appear in the scrolling list.
The Channel Number buttons at the top of the window let you hidechannel-specific comments. Comments for channels with highlighted
buttons appear (by default, all of them): click to deselect or reselect achannel. Comments applying to all channels are not affected by thesebuttons. The Show Comments and Show Exclusions checkboxes let you
choose which categories of comment appear: by default, both are on,
but you can turn a checkbox off to hide all comments in that category(at least one must be on). Type text in the Filter text entry box to show
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only comments containing that text (ignoring case and context, so ‘new’also covers ‘New’ or ‘newer’).
The Show Times checkbox (on by default) precedes comments with thetimes at which, or time ranges over which, they appear. If you turn it
off, then times do not appear, either in this window or in the list ofcomments printed from it.
The Time column shows the times or time ranges in the form set bydisplay settings. Column widths can be changed, for instance to give
more room if comments in the list are truncated, or if the times are shortrather than time ranges or times of day. Position the pointer on thedividing line so that it changes into the resizing pointer, drag until thecolumn is the desired width — a gray line appears, to indicate position— then release the mouse button.
Once a comment in the list is selected (by clicking it), then it may beedited, deleted, or located (comments selected in the list will show
control handles in the Chart window). The pointer changes to an I-beamover text in a single selected row, and the text can be edited normally.
The channel identifier, comment number, time, and category cannot bealtered here. If the Delete button is clicked, a selected comment isdeleted. To choose multiple comments for deletion, drag or Shift-click to
select contiguous comments, or Command-click to select or deselectmultiple comments individually.
If a comment is selected and the Go To button is pressed, the Chart
window becomes active, the comment is located and centered in thedata display area, and a brief animation shows its position. Currently
hidden comment boxes are made visible again. Lines and areas, or text
labels, may also be made visible if their checkboxes are on in the
Display Settings dialog box. This is very useful for locating commented
features or excluded areas in the file. If you have multiple comments
selected, the comment at the top of the list is the one centered in thedata display area. If the data display area is split into two panes,
comments are located in the right pane.

Comment Numbering
When comments are deleted, the numbers for the remaining comments
in a file do not change (this helps to prevent confusion when editing
files). When a file is appended to another file, the comments in the122

Chart Software

appended file remain in the same order, but are renumbered following
on from the highest comment number in the file to which it wasappended.

Identifying a Data Point
If the Marker is dragged to a comment box in the Chart window, thebox will highlight. When released, the Marker locates itself on a data
point recorded at the time the comment was made (the start of acommented area). If the comment is channel-specific, the Marker islocated on the waveform of that channel, if it has data; else (if thecomment applies to all channels, say), the Marker is located on the
waveform of the top channel.

Printing Comments
If the ‘Text Label’ checkbox is on in the Display Settings dialog box,
comments are printed where they in the data print-out when you are
printing a whole file or a selection. When the Comments & Exclusions
window is active, then the Print option in the File menu changes to Print
Comments…, and if the command is selected, the contents of thiswindow are printed rather than those of the Chart window. Comments
are printed out as a numbered list, with the numbers boxed. Only thosecomments chosen for display using the Channel Number buttons in theComments & Exclusions window will print. If the Show Times checkbox
is on, then times (start times, not time ranges) will be printed; if it is off,times are not printed. Categories are not printed. This helps if you havelong comments, since comment text longer than one line will not be
printed — an ellipsis (…) in the print-out indicates truncated text.

Using Exclusions
Artifacts in a recorded signal can interfere with analysis. Large data
spikes can result from bumping laboratory equipment, adjustingmeasuring electrodes, and so on, especially with sensitive recordings.
Temporary loss of a signal can result from a loose connection. Whenrecordings are analyzed, such glitches, unrepresentative of the signals
being measured, can show up as serious anomalies in derived readingssuch as frequency, peak height, cyclic variables, and so on.

Chapter 5 — Working With Files123Exclusions are a way to mark invalid data without removing them fromthe file. If you just delete the data, the action creates a time
discontinuity (and hence a new block boundary). A selection must also
be deleted over all channels. An exclusion can apply to a single
channel, so otherwise unaffected data on other channels are not lost,and it doesn’t create a new block: excluded data are simply ignored
for most calculations and analysis, saving as text, and so on. The text ofthe exclusion can be used to indicate why the point or area was
excluded. Since exclusions are easily added and deleted, you can also
use them to exclude data temporarily to see what effect this has on
particular readings.

Finding Files
It is simple enough to organize a small number of data files with a very
basic filing system using a few folders. Once a large number of files
have been recorded, especially if there are many similar ones, the task
becomes harder. Chart’s file information feature helps you to keep trackof data files. Suitable information can be stored in a file, and then(along with any comments in the file) can be searched for, so that you
can quickly find a specific file when it is wanted.

File Information
Choose File > File Information… to prepare a file for later searches: theFile Information dialog box appears. Enter text in the various fields
according to some suitable system. The title can be a longer version of
the file title. The Other field lets you enter extra keywords, for instance,or descriptive text (perhaps transferred from the Notebook). The Ask for
Information pop-up menu determines when all this is asked for. By
default it is set to Manual, which means you must remember to choose
the menu command to add the information. You can make Chart
request file information by choosing one of the other options. If Before
Saving is chosen, then the File Information dialog box appears for you
to enter information when you save a file. If Before Sampling is chosen,
then the dialog box appears when you click the Start button. Click theCancel button to dismiss the dialog box without entering information, or
the OK button to accept any entered text. The text is not saved withsettings, but the state of the pop-up menu is.

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Chart Software

Figure 5–22
The File Information
dialog box.

Searching for Files
Choose File > Find File… to find a Chart file using its internal fileinformation: the Find File dialog box appears.
The Search in pop-up menu lets you choose where to search: local
disks, all currently available disks including mounted servers, or any
specific disk. The Search field pop-up menu lets you choose which of
the five fields Title, Author, Keyword, Other and Comments to search
in. The first four of these fields correspond to those in the File
Information dialog box, and the last lets you search the comment text offiles, which is useful for files that lack specific file information. Enter the
text to search for in the Contains text box (ignoring case and context,so ‘new’ also finds ‘New’ or ‘newer’), and click the Find button to lookfor files.

Figure 5–23
The Find File dialog box.

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125

While the search is under way, the Found Files dialog box appears.
The search criterion is shown under the dialog box title: as files
matching it are found, they are added to the File List in the top half ofthe dialog box. To halt the search at any time, click the Stop button.
Once the search is finished, the File List shows which files have beenfound, with the context of the found text shown at the right. Click to
select one of the found files: its location is shown in the File Location Listin the lower half of the dialog box. If the search proved unsatisfactory,
you can click the Find Again… button to open the Find File dialog box
once more, and try a different approach. Click the Open button to
open a selected Chart data file.

Figure 5–24
The Found Files dialog
box.

Backing Up Files
It is always good practice to back up computer files. Computers arereasonably reliable, but file corruption, disk failures, and accidental
deletion of data can still occur. If your Chart files are important, you
should back them up. You can get data backup software to do thisautomatically, or you can set up a backup schedule yourself. Off-site
and Internet-based backup services are available as well. It helps if
things are well organized, and your files and folders sensibly named
and arranged. (If it takes you as long to find the backup as it would torecord the data again, you haven’t saved yourself much work.)
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Chart data compression is very good, so you don’t save too muchspace by archiving data files. Simply copying them to another disk isenough (having copies on the same disk doesn’t help if the disk fails).
The most reliable backup media are recordable CDs, magneto-opticaldisks, or hard disks (including servers, especially if they also have tapebackup). Floppy disks are best treated as temporary media only.
If you back up files onto a computer using the Windows OS, becareful. Try to make sure the files are only handled from the Mac OS.
Windows systems typically do not understand Macintosh files, and may
discard information such as the file type or resource fork if the files aremanipulated by the OS or an archiving program. Chart files should still
be recoverable even if the file type and resource fork are lost. It may benecessary to add “.cfm” to the file name in the Finder to force Chart torecognize it as a Chart file.
Always test your backup procedures as fully as possible. Try backing
up and retrieving sample files to make sure things work before working
with critical files.

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127

128

Chart SoftwareC H A P T E R

6 Data Analysis

S I X

The whole purpose of recording data, of course, is to find things out
through analysis of the recording. Chart offers a wide range of online
and offline calculations and makes it easy to extract parameters andstatistics from your data.

This chapter discusses Chart’s many analysis options.You can measureabsolute or relative quantities with the Waveform Cursor, andcalculate, store and export further parameters with the Data Pad. You
can plot data from one channel against that from another using the X–Y
window. You can arithmetically combine data in different channels,smooth data, and analyze the cyclic components or the derivatives andintegrals of your signals. This can be done during sampling byapplying Computed Input functions, or after recording by using channel
calculations. You can also use the Spectrum window to analyze thefrequency components of your data.

Chart Software

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Measuring from the Waveform
When you have finished recording, you can scroll through your data
and make measurements directly from the recording — since everythingis digital, you are given a direct read-out, with no chance of themeasurement errors that could occur in analyzing a paper-and-ink
record. You can make direct or relative measurements.
When the pointer is over the data display area (or Time axis), theWaveform Cursor for each channel tracks the waveform at the time
position of the pointer. In this case, the Rate/Time display shows thetime at the pointer location, and the Range/Amplitude display for eachchannel shows the amplitude of the waveform at the Waveform Cursor
location. The Waveform Cursor only gives discrete measurements,
jumping from data point to data point (you can see this more clearly in
the Zoom window). It cannot provide a reading on the line that is
drawn between the points for display purposes.

Figure 6–1
Measuring waveform
data.

Time at pointer(and Waveform
Cursor) position
Pointer

Waveform▼ Refer
Cursor, p. 192

130

Amplitude at
Waveform
Cursor position

The pointer appears as a cross over the data display area (or a doubleheaded selection arrow along the Time axis). The Waveform Cursor’s
shape is a cross by default, but can be changed in the file preferences
to suit the waveform.

Chart Software

Using the Marker
The Marker can be found at the bottom left of the Chart window. It is
used to set a particular data point as a zero reference point, so that
relative measurements can be made with respect to that point.
To set the reference point, drag the Marker into the channel of interest;
it will lock onto the waveform there when you release the mouse button.
Watch the changing numbers in the Rate/Time and Range/Amplitudedisplays to help to select a data point. If you need finer control of
where the Marker ends up, use the Zoom window to look at a selection
in more detail: the Marker is duplicated there, and can more easily be
assigned to a particular data point.
If there is a selection in the Chart window, you can choose commands
from the Set Marker submenu of the Commands menu to locate theMarker where you want it: Minimum Point, Maximum Point, First Point,or Last Point. The Marker is then moved to the lowest, highest, left-most,or right-most points in the selection respectively, either in a specificchannel, or the top one of several. If there is an active point in theChart window, any of the commands moves the Marker to the positionof the active point.
Once the Marker is in position, measurements relative to it (precededby ∆) are given in the readings for time in the Rate/Time display as thepointer moves. The reading in the Range/Amplitude display for thechannel where the Marker is located is also relative to the Marker, but
the values at the Waveform Cursor positions for the waveforms in otherchannels are absolute. The ‘∆’ (delta) symbol before a value indicates it

Figure 6–2
Measuring relative
waveform data.

Time at pointer position
relative to Marker
Marker

Amplitude at
Waveform Cursor
position relative toMarkerAbsolute amplitude (indifferent channels toMarker)

Chapter 6 — Data Analysis

131is a difference, not a direct reading. Derived values (in the Data Pad
and so on) take the Marker into account when appropriate.
The Rate/Time display indicates if the pointer is not in the same blockas the Marker, and if the block has a different scale or different units tothe one the Marker is in, the Range/Amplitude display reads ‘∆ Range
Invalid’ as well.
If the Marker is dragged to a comment box in the Chart window andreleased, the comment box highlights and the Marker locates itself on
the data point recorded when the comment was made, either in thechannel of a channel-specific comment, or the top channel otherwise.
Double-clicking the Marker or clicking its box at the bottom left of theChart (or Zoom) window sends it back to its box.

Setting and Removing Baselines
The Set Baseline command is used for setting relative amplitude
measurements where the voltage (amplitude) baseline of a channel is
not zero. Once you have recorded a waveform, you may find that thebaseline value is not zero volts (or set units) when it should be — thatis, there is some slight offset. To remedy this, select an active point or
area along the waveform where the measurement should be zero, andchoose Commands > Set Baseline. The value at that point or the
average of the selection is set at zero, and scale units of the Amplitude
axis change to show this. The position and size of the waveform in thechannel display does not change: if you want it altered, simply drag or
stretch the scale.
The baseline is set for the particular block or blocks of data in achannel that the selection intersects. To set the baseline across thewhole channel for all blocks of data, hold down the Command key
while choosing Commands > Set Baseline. Remove Baseline removes abaseline previously set, and also affects the selected block or blocks ofdata in a channel. Holding down the Command key while choosing
Commands > Set Baseline removes any set baselines across the wholechannel.

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Finding Data
The Overview miniwindow gives an overview of a channel, where you
can see longer-term trends, and find particular events on a large scale.
The events you want to find may be of smaller scale, and may not be
obvious in overview. Chart therefore provides another method to findand select data of interest in a recording, according to criteria you
specify. It also helps in automating searching by macros. To find data,choose Commands > Find… or type Command-F: the Find and Selectdialog box appears (Figure 6–3).

Figure 6–3
The Find and Selectdialog box.

Channelto search
Generalsearchcriteria
Explanationof selected
optionSearchdirection
arrowsSpecific
searchcriteria

Selection
criteria

You can set up search and selection criteria as desired, to search any
channel for comments, peaks and troughs in the waveform, blockboundaries, and so on, and to set the active point at the position found,or select data for a period before, around, or after it, for the active
channel or all channels.

Search Criteria
You can search for an event in a specific channel or in the current
channel (the default), that is, the one with a current selection or active
point. If the active point or selection in the Chart window extends
across multiple channels, then the topmost one is searched. Use theChapter 6 — Data Analysis

133

Channel pop-up menu at the top left of the dialog box to choose thesearch channel from the list of channel titles. Two scrolling lists let you
select from the many forms of information that could be sought. The lefthand list gives the general type, and the right-hand one options
available in that set. The selected option is briefly explained in a box
beneath the two lists. The exact controls in the dialog box depend on
what is chosen in the scrolling lists.

Go
Go can find the start or end of the file or the current block within thefile, the start of the next block, or the end of the previous block. You
can also move forward or backward through a file by a set time inseconds. If you select the Move Forward or Move Backward options, atext entry box appears, in which you can type in a number from
0.00001 to 10 000 seconds, in increments of 0.00001 seconds (thetime between samples at 10 000 samples per second). This always
moves at least one data point, whatever the sampling rate.

Find Comment
Find Comment searches for text in comments (including exclusions).
There is only one option in the list; the search direction is set by the
direction arrows to the right of the Channel pop-up menu. Click theright one to search forward, the left one to search backward.
Two more controls appear beneath the scrolling lists: type text in the
text entry box to find only comments containing that text (ignoring caseand context, so ‘new’ also finds ‘New’ or ‘newer’). Turn on the Just thisChannel checkbox to find only comments that apply to the searchchannel (ignoring channel-specific comments in other channels).

Find Data▼ Refer
Using Exclusions,p. 123

Find Data can search for local maxima or minima, or data points
above or below a set value. The search direction is set by the direction
arrows to the right of the Channel pop-up menu. Click the right one tosearch forward, the left one to search backward. These searches ignore
excluded data (points and areas marked by exclusions).
If you select the Local Maxima or Local Minima options, Find Data
searches for peaks or troughs respectively. A text entry box appears, in

134

Chart Softwarewhich you can type in a number from 1 to 90 to set a noise thresholdfor the event, as a percentage of the range of the channel (the default
value is 5%, which is 1 V for a ±10 V range). For a data point to berecognized as a peak or trough, the data points that follow must
decrease (for a local maximum) or increase (for a local minimum) by atleast the noise threshold value. Local maxima and minima in the
waveform with smaller amplitudes than this value will be ignored. Raisethe value to get rid of unwanted small fluctuations (noise and so on);lower it to detect missed events.
If you select the Data Above or Data Below options, a text entry box
appears, in which you can type in a value from ±0.00001 to ±10 000
to set the value, in whatever units are assigned to the search channel.
The first matching data point above or below the set value is found.

Selection Criteria
Once an event is found, an active point or selected area is set in theChart window, using the controls at the bottom of the dialog box.
The Select All Channels checkbox is off by default, in which case theactive point or selected area set by the command is confined to thesearch channel. If the search channel is in a set of overlaid channels,
then all channels in that overlay will be selected. A selected area will
extend to the full height of the channel or channels. Click the checkbox
to turn it on and set an active point or selection area over all channels,
as if you had clicked or dragged in the Time axis.
Choose the Set Active Point radio button to set an active point at thetime of the event. Choose the Select to Previous Point radio button to set
a selection area from the time of the event to the nearest boundary of
the previous selected area, or the previous active point. If you choose
the Select radio button, a text entry box and pop-up menu appear.
Type in a time from 0.00001 to 32 000 seconds to set the horizontal
extent (duration) of the selected area. Choose one of the options in the
pop-up menu: After, Around, or Before. After selects an area from thetime of the event forwards; Before selects an area from the time of theevent backwards. Around selects an area of data symmetrically aroundthe time of the event.
The active point or selection area set is shown in the Chart window if it
is not visible already. You can choose from the Data View pop-up menu

Chapter 6 — Data Analysis

135whether the found data are merely visible, or shown at the left or rightof, or centered in, the Chart data display area. Setting a fixed position
is useful for repeatedly finding data, since you can keep looking at thesame area of the screen as you go through the file.

Repeatedly Finding Data

▼ Refer
Macros, p. 202

Once the criteria for finding and selecting an event have been set up,
you can choose Commands > Find Next or type Command-G to findand select the next such event. You can repeat this command asneeded to find multiple events (it will repeat at your keyboard’s autorepeat rate if you hold the keys down). This is easier than scrollingthrough manually to look for events, and is very useful in conjunction
with macros, for instance, to select events in a channel automaticallyand record information to the Data Pad.
If the Find… or Find Next commands fail to find an event (because theselection would move outside the file boundaries, for instance), thenChart will beep.

The Data Pad
The Data Pad is used to analyze waveform data. It is easy to set up anduse; you can record up to 32 columns of data in it, either direct
waveform values or calculated values from any channel, from active
points or over selected areas. The Data Pad can store large amounts ofdata — up to 32 000 rows, with each row having a maximum of 255

Figure 6–4
The Data Pad window.

RowbuttonCellbuttonColumnheadings

Data Pad
pop-upmenu
Data oncurrent
selection

Recordeddata

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Chart Software

characters per cell, and a total of 2000 characters per row over the 32
columns. Its contents can be saved as a text file or copied in whole orpart to the Clipboard for transfer elsewhere. To open the Data Pad,
choose Window > Data Pad.
The Data Pad is a normal window and can be moved around thescreen or left in the background while the Chart window is active.
Information on the current selection or active point is displayed justabove and beneath the column headings: the readings beneath thecolumn headings are separated from recorded data by a heavy line,
and are centered rather than left-justified to help to distinguish them. As
data are added to the Data Pad, new rows of values are created below
existing rows in the data area. Each cell contains only one entry, thevalue added to the Data Pad at the time the calculation for its column
was made. The column heading shows the title of the channel fromwhich the reading currently derives. Use the scroll bars to move downor across through rows and columns.
The two tools used to deal with data in the Data Pad are chosen using
buttons at the top left of the window. By default the Row tool is selected(and the leftmost button, with the pointer-like arrow, highlighted): in thiscase, the pointer changes to a heavy cross when over the data area.
Click to select a row, drag or Shift-click to select contiguous rows, orCommand-click to select or deselect rows individually; the data canthen be cleared, or cut or copied to the Clipboard as tab-separated
text, using the commands in the Edit menu (Cut, Copy, Paste, Clear). If
the Cell button (with the A) is clicked, the pointer changes to an I-beam
when over the data area, and text in each cell can be edited in thenormal way. Clicking the Cell button deselects all selected rows.
The pop-up menu to the right of the window lets you add to the Data
Pad either blank lines (rows), or the full current column headings as
three lines — useful to keep track of changed settings, or whentransferring data to other applications. (Superscripts and subscripts incolumn headings are converted to plain text when added to the Data
Pad.) You can also choose whether to keep or clear the Data Pad
contents when a new file is created: a tick appears beside the lowest
menu command when it is active (it applies only to the current file).
The width of columns can be changed to suit the displayed data andheadings. You might want to narrow columns to display more on
screen, for example, or have a wide column to the right in which to

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137add comments. Position the pointer on the heavy dividing line between
column headings, so that it changes into the resizing pointer, drag until
the column is the desired width — a gray line appears, to indicate
position — then release the mouse button.

Adding Data to the Data Pad
To add data on a selection or active point in the Chart window to the
Data Pad, choose Commands > Add to Data Pad or type Command-D.
As a shortcut, you can double-click in the data display area to transfer
data at a point (double-clicking in the Time axis selects a block, though,and transfers no data). If you need finer control of what is transferred,
use the Zoom window to look at a selection in more detail: a particular
data point can be double-clicked more easily.

▼ Refer
Using Exclusions,p. 123

If a selection straddles two or more blocks and the blocks have different
units, the selection will be noted as having multiple units rather than any
Data Pad calculation being attempted. Exclusions (points or areas
marked as excluded from analysis) are treated as separate blocks
containing no valid data, so no calculations based on that data areattempted. Exclusion comment text is also ignored. Time and selection
values for excluded data are returned, however.
The data recorded depends on the choices made in the Data Pad
Column Setup dialog box. By default, the first few columns are set torecord the mean of the selection in a channel (or, when there is anactive point, the waveform value at that point). Any column can record
data from any channel, though (so you could have any number ofvariables deriving from Channel 1, for instance).

Setting Up the Columns
The data recorded in the Data Pad depends on the choices made in the
Data Pad Column Setup dialog box: it appears on clicking a column
heading, and will have the column number (1–32) in its title.
Note
Other functions may be
added to the Data Pad
through Chart
extensions.

138

To move to the dialog boxes of adjacent columns (and set up manycolumns quickly), click the arrows by the dialog box title, or press theright or left arrow keys on the keyboard. Click OK to close the dialog
box after you have set up all the columns you need. Two scrolling lists
let you select from the many forms of information that could be

Chart Software

Figure 6–5
The Data Pad Column
Setup dialog box.

recorded, whether derived or direct. The left-hand list gives the general
information type, and the right-hand list options available in that set.
The selected option is briefly explained in a box beneath the two lists.
The channel from which data are taken is selected in the Channel popup menu at the right of the dialog box.
Off simply turns the column off: no data are recorded in it. This will
disable and dim the radio buttons and Channel pop-up menu.

General Statistics
Mean calculates the mean of the data points in the selection, or returns
the value at the active point. Standard Deviation calculates the standard
deviation of the data points in the selection. Standard Error calculates
the standard error of the mean of the data points in the selection.
Maximum Value returns the value of the largest data point in theselection. Time at Maximum returns the time at which the largest data
point in the selection was recorded. Minimum Value returns the value ofthe smallest data point in the selection. Time at Minimum returns thetime at which the smallest data point in the selection was recorded.
Max–Min calculates the difference between the largest and the smallest
data points in the selection (zero for an active point).

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Integral returns the integral of the selection, calculated as the sum of thedata points multiplied by the sample interval; ∑y ∆t. Integral from
Minimum returns the integral of the selection, calculated as the sum of
the data points minus the minimum value in the selection, multiplied by
the sample interval; ∑(y–ymin) ∆t. Integral from Start returns the integralof the selection, calculated as the sum of the data points minus the firstvalue in the selection, multiplied by the sample interval; ∑(y–yfirst) ∆t.
Integral from Baseline returns the integral of the selection, calculated as
the sum of the data points minus the value on a baseline (drawn fromfirst to last data points in the selection), multiplied by the sample
interval; ∑(y–ybaseline(t)) ∆t.
Number of Points returns the number of data points in the selection (onefor an active point). RMS calculates the RMS (root mean square) valueof the data points in the selection, or returns the value at the active
point. 1/3Max + 2/3Min calculates 1/3 of the maximum value plus
2/3 of the minimum value of the data points in a selection, or returns
the value at an active point.

Selection Information
Start returns the start time of a selection, or the time at the active point.
End returns the end time of a selection, or the time at the active point.
Duration returns the duration of a selection, or the sample interval foran active point. Number of Points returns the number of data points inthe selection (one for an active point).

Cursor & Comments
Time returns the start time of a selection, or the time at the active point.
Value returns the value at the start of a selection, or the value at theactive point. Comment Full extracts the full comment text. Comment
Numbers Only extracts the first number from comment text (e.g. ‘Add
100 mL of 2 mM’ would return ‘100’). Comment Number returns thenumber of a comment. Comment Time returns the start time of acommented area, or the time at a commented point. For comments, ineach case the Data Pad looks for the first comment to the left of anactive point or from the right edge of a selection. Comment Duration
returns the duration of a comment.

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SlopeAverage Slope returns the average slope (time derivative) of the data
points in a selection, or the slope at an active point. The average slope
is calculated from the least-squares line of best fit. Maximum Slope
returns the maximum slope of the data points in a selection, or the slope
at an active point. Minimum Slope returns the minimum slope of thedata points in a selection, or the slope at an active point. Time at Max
Slope returns the time at which the maximum slope in a selection
occurs, or the time at an active point. Time at Min Slope returns the timeat which the minimum slope in a selection occurs, or the time at an
active point.

Block Information
Range returns the range used when recording for the block containing
the active point or selection. Sample Interval returns the time between
samples for the block containing the active point or selection. Block
Number returns the block number for the block containing the active
point or selection. Block Duration returns the total time of the blockcontaining the active point or selection. Samples in Block returns thetotal number of samples in the block containing the active point. Start
Time returns the time of day at the start of the block containing theactive point or selection. Start Date returns the date at the start of blockcontaining the active point or selection. Sampling Rate returns the
sampling rate used when recording the block containing the active
point or selection. If a selection straddles two or more blocks, however,then it will be noted as discontinuous.

Cycle Variables▼ Refer
Cycle Variables, p. 176

Cycle Variables parameters are for analyzing periodic waveforms. The
calculation of each parameter is based on waveform cycles. When a
Cycle Variables parameter is selected in the Data Pad Column Setup
dialog box, an Options… button appears. Clicking this button allows
you to set up the way in which waveform cycles are detected, in thesame way as you do when using the Cycle Variables channel
calculation.
The way in which you set up cycle detection applies to the detection of
all cycle variables in the channel chosen in the Data Pad Column Setup

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dialog box’s Channel pop-up menu. This is handy when you havemultiple columns in the Data Pad showing various cyclic calculations fora single channel, since the detection parameters only need be set up orchanged once for the whole lot. Any changes made to the cycle
detection settings for a particular channel here will affect the Cycle
Variables calculations for that channel as well, and vice versa.
Cycle Variables parameters can only be calculated if there is a valid
selection. The Data Pad and Data Pad miniwindow displays show
certain messages when Cycle Variables cannot produce a useful result.
‘No Selection’ shows if there is no selection, but only an active point,
for example. ‘Invalid’ shows if the selection crosses a block boundaryor is in a channel with no data, or if no Cycle Variables or cycles aredetected (for instance, there is less than a full cycle from which to
calculate a peak-to-peak value).

▼ Refer
The Spectrum Window,
p. 147

Event Count counts the number of events in a selection. Cycle Countcounts the number of cycles in a selection. This will be zero if there is
only one event. Frequency calculates the average frequency of thecycles in the selection in cycles per second (Hz). Rate calculates theaverage frequency of the cycles in the selection in reciprocal minutes(BPM, beats per minute). Average Period calculates the average period
between the cycles in the selection. Minimum Period calculates theminimum period between the cycles in the selection. Maximum Period
calculates the maximum period between the cycles in the selection.
Average Minimum calculates the average of the cyclic minima in theselection. Average Maximum calculates the average of the cyclic
maxima in the selection. Average Peak-to-Peak calculates the averageof the cyclic peak-to-peak (maximum minus minimum) differences in theselection. Average 1/3Max+2/3Min calculates the average of thecyclic 1/3Max+2/3Min values in the selection. (1/3Max+2/3Min
calculates 1/3 of the maximum value plus 2/3 of the minimum value ofthe data points in a cycle.)

Spectrum Parameters
Spectrum parameters are based on spectra which are calculated
according to the settings in the Spectrum Settings window, anddisplayed in the Spectrum window. When a Spectrum parameter isselected in the Data Pad Column Setup dialog box, an Options…
button appears.

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Figure 6–6
The Spectrum Parameter
options dialog box.

If there is a selection of valid data in the Chart window, Spectrum canperform a range of calculations in the Data Pad to determine thespectral parameters. The Spectrum window does not need to be visible
in order for these parameters to be calculated. The Data Pad andminiwindow displays show ‘Invalid’ if there are no selected data. To
preset frequency limits, or choose whether or not to display (in the Data
Pad headers) the frequency limits within which the parameters arecalculated, click the Options… button at the bottom of the Data Pad
Column Setup dialog box. The Spectrum Parameter Options dialog box
appears.
If you know the range of frequencies in which you are interested, you
can turn on the Preset Frequency Limits checkbox and enter them in the
text entry boxes. Parameters are then calculated from between thosefrequency limits (or as close as possible, given the frequency
resolution). If the checkbox is off, then parameters are calculated overthe frequency limits of any selection in the Spectrum window, or else
the frequency range visible in the window if there is no selection.
Turn on the Show Frequency Range in Data Pad checkbox to display
the frequency range used by Spectrum in calculating parameters, in the
Data Pad column headers, and in the Data Pad miniwindows (itappears in brackets after the units).
Maximum Power displays the maximum power. Minimum Power
displays the minimum power. Maximum Amplitude displays the
maximum amplitude. Minimum Amplitude displays the minimum
amplitude. Frequency at Max displays the frequency at maximum
power/amplitude. Frequency at Min displays the frequency at minimum
power/amplitude. Power displays the power. % of total Power displays
the percentage of the total power. Mean Amplitude Freq displays themean amplitude frequency; ∑ Ai Fi / ∑Ai where A is amplitude, F is
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143frequency, and i is the ‘bin’ number. Mean Power Freq displays themean power frequency; ∑ Pi Fi / ∑Pi where P is power, F is frequency,
and i is the ‘bin’ number. These options are calculated over all thefrequency bins in the frequency range. The range used is set by either
the preset frequency limits, or failing that, the frequency limits of any
selection in the Spectrum window, or failing that, the frequency range
visible in the window.
Start of Selection displays the time at the beginning of the data
selection used to generate the spectrum. End of Selection displays thetime at the end of the data selection used to generate the spectrum.
These options refer to the selection in the Chart window.
The three radio buttons indicate when information is to be recorded. If
the top one is selected, then if there are any data selected in the Chart
window, information will be recorded about the channel selected in the
Channel pop-up menu (if you have selected an area in Channel 2,
information on Channel 3 would still be recorded, for instance). If the
middle radio button is selected, information is recorded about thecolumn channel only if that channel is included in the selection. If thebottom radio button is selected, information is recorded only about thelowest-numbered channel if more than one is selected (Channel 2 if
Channels 2 to 4 are selected, for example). Data transfer from theZoom window is always as if the top radio button were selected,
regardless of the settings.
The Compact Data checkbox works together with the middle radio
button: if you select data from different channels at different intervals
after the same stimulus, say, it will place all the data on the same line in
the Data Pad (if the checkbox is off, then each entry will be recorded
on a new line). It doesn’t work if you record times as well, so it is only
useful for simple data capture.
Its various functions make the Data Pad useful for quickly finding out
information about a file or blocks in it: you can leave the Data Pad
itself, set up to display the required information, as a slim visible
background window that will be constantly updated. In addition,
miniwindows can be created to display the current values of statistics or

Figure 6–7
Data Pad Value
miniwindows.
144

Chart Softwaremeasurements set up in particular columns from the Data Pad. To showor hide the miniwindow for a column, turn on or turn off the
Miniwindow checkbox in the Data Pad Column Setup dialog box, ordrag the column heading to tear it off. Drag the miniwindow by its title
bar to where you want it, click the close box to dismiss it, or click its
body to open the dialog box again. Its title bar contains its column
label and its body the heading, to indicate what it displays. Data Pad
miniwindows can be resized by dragging their bottom right corners.

Printing
When the Data Pad window is active, then the Print option in the Filemenu changes to Print Data Pad…, and if the command is selected, thecontents of the window are printed with the title ‘Data Pad from’ andthe file name. The Data Pad will print across two or more pages if it is
wide enough, but empty columns are not printed.

The X–Y Window
By using the X–Y window, you can plot data in one channel against
data in another over the same period of the recording. To open the X–Y
window, drag in the Time axis to select an area of interest (over two or
more channels) in the Chart window, and then choose Window > X–Y
Window.

X and Y values atthe pointer position

Figure 6–8
The X–Y window.

Y channel

Channel Number buttons

Pointer

The axes act like the
Amplitude axis in theChart window
X channel

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The X–Y window is useful to establish how two time-related variables
relate themselves, by eliminating time: you could measure pressure andtemperature versus time, say, then use the X–Y window to showpressure versus temperature. It would also show phase relationships,
such as the hysteresis loop of a changing external field versus its
induced ferromagnetism. The values along the x-axis (X) and y-axis (Y)at the pointer position are indicated at the top of the window, in theunits assigned to the channels. The waveform is not tracked: there is no
Waveform Cursor.
The Channel Number buttons at the bottom left (horizontal x-axis) andright side (vertical y-axis) of the window correspond to the numbers in
the default channel titles. Buttons for channels not included in theselection, or without data, appear dimmed. The highlighted Channel
Number buttons indicate which two channels are used in the plot: thebottom one provides the x-values, and the one on the right the y-values.
The channels plotted against each other can be changed by clicking the(undimmed) numbered buttons: the buttons of the newly selectedchannels will be highlighted.

▼ Refer
Display Settings, p. 77

Both X and Y axes in the X–Y window have the same controls as the
Amplitude axis in the Chart window, and function identically. Changing
the display in the X–Y window does not affect the selection in the Chart
window. The display will appear gray if no channels are selected in theChart window or if no Channel Number buttons are selected. The X–Y
window does not indicate if the selection in the Chart window is
discontinuous (crossing block boundaries), but the X–Y plot willprobably look strange if it is. The color for the waveform is chosen in
the Display Settings dialog box. Comments and exclusions are ignoredby the X–Y window, since they are time-based, and the X–Y plot
eliminates time.

Copying and Printing the X–Y Window
When the X–Y window is active, then the Print option in the File menuchanges to Print X–Y…, and if the command is selected, the contents of
the window are printed with the title ‘XY Plot of’ and the file name. The
X–Y window can also be copied as a picture for pasting into otherapplications, by choosing Copy X–Y… from the Edit menu.

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The Spectrum Window
The Spectrum window can calculate and display various power andamplitude spectra of selected data. Spectra indicate the strength of thevarious frequencies in a time-varying waveform. This may makeapparent significant frequencies in a waveform that would nototherwise be easily observed. Spectra (various forms of power oramplitude spectra) are calculated using the discrete Fast Fourier
Transform (FFT) to convert data from the time domain to the frequency
domain. Technical details of the FFT used by Spectrum are included inAppendix C.

Figure 6–9
The Spectrum window:
the type of spectrum(power or amplitude) andchannel name are shownin the title bar.

Settings
buttonScaling
buttons

Default Axes
buttonFrequency and amplitude readings

FFT
information

Waveform Cursor

To display spectra, select the area of interest in the Chart window andchoose the Spectrum command from the Window menu. The Spectrum
window appears. Only the horizontal extent of the selection affects thecomputation. If more than one channel has data selected, the top one ischosen. If a selection is made over two or more blocks, Spectrum uses
only the data in the left-most block. The data display area will appear

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gray if there is no selection (in which case the title of the window will
just be Spectrum), or if 32 or fewer data points are selected: the reason
will be noted in the selection information at the right of the window.
The Spectrum window displays information on the data selection. As
the pointer is moved over the Spectrum data display area, theWaveform Cursor tracks the data, and the frequency and amplitude
readings at its position are displayed at the top of the window. The
spectrum is drawn in the data trace color used for the channel, and canbe drawn as lines, bars, or connected points. The graticule is the sameas that used in the Chart window.
The two axes of the Spectrum window can be shifted, stretched, anddragged for optimum data display, just like the Amplitude axis of achannel in the Chart window. In addition, you can use the Scaling
buttons in the bottom left corner of the window: click the up arrow todouble or the down arrow to halve the current scale of the axis towhich they apply. If no units are present in the source channel the
Amplitude axis will show units as ‘unknown’.
You can drag within the data display area of the window to select anarea to examine in more detail: the area becomes highlighted, and theZoom button appears at the top left of the Spectrum window (replacing
the Default Axes button). Click the Zoom button or double-click theselected area: the selection expands to fill the data display area, andthe axes show the new scale.
A gray area may appear at the edge of the Spectrum window. This is adata limit area (as appears in the Chart window) that indicates the

Figure 6–10
Enlarging a selection in
the Spectrum window:
click the Zoom button or
double-click the selected
area.

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recorded or calculated limit of data in the window. To hide the data
limit area, drag the axes or use the Scaling buttons.
Altering the data displayed in the Spectrum window does not change
the selection in the Chart window. Once you have altered the axes,
zoomed in, and so on, the Default Axes button appears (replacing theZoom button if it was showing). Click it to revert to the default axes,
and show the full spectrum of the selection in the Chart window again.
The Default Axes button is dimmed and inactive when the default axes
are showing (since there’s nothing to revert) or when the data display
area is gray.

Spectrum Settings
Clicking the Settings button at the top left of the Spectrum window
opens the Spectrum Settings window, where parameters for calculationand display of the spectrum can be set. The Spectrum Settings window
can be moved around the screen or left in the background while theChart or Spectrum window is active. You can keep it active andchange the settings, and observe the changes in the Spectrum window
in the background, if that window is visible: the spectrum will berecalculated or redrawn as you change settings.
FFT Size. The Discrete Fourier Transform is computed using a Fast
Fourier Transform (FFT) method. The FFT works on a certain number ofdata points at a time over the selection to be analyzed. The larger that
number, the greater the frequency resolution (the number of frequency‘bins’ into which the signal is resolved). Smaller FFT sizes give a higher

Figure 6–11
The Spectrum Settings
window.

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amplitude accuracy, but a lower frequency resolution. The FFT sizes
available in the pop-up menu are various powers of two: 128, 256,
512, 1024, 2K (= 2048), 4K (= 4096), and so on, up to 128K (= 131
072 = 217) data points. This is indicated in the window above thegraph.
Data Window. Windowing functions reduce the importance of data at
the edges of the data segments used by the FFT, thus preventing
spurious peaks arising from edge-related effects. There are many suchfunctions, but they are all basically similar. By default, Cosine Bell ischosen in the Data Window pop-up menu, but you can choose Cosine
Bell, Hamming, Blackman, or Welch windowing functions. More details
on the windowing functions can be found in Appendix C. To turn off
the windowing functions, if none of them are suitable, choose Nonefrom the pop-up menu.
Method. If the number of selected data points is greater than the FFT
size, Spectrum determines the spectra of selected data for successive
segments of a particular FFT size and then calculates an average
spectrum from these FFTs. You can choose from the Method pop-up
menu whether successive segments follow one after another with nooverlap, or overlap by 50% of the FFT size (the default). If a windowing
function other than None is chosen, the Method of computing thespectrum changes to 50% Overlap.
If No Overlap were chosen from the Method pop-up menu, a data
selection of 1024 points with an FFT size of 512 points, for example,
would be divided into two segments: points 1–512 and points
513–1024. If 50% Overlap were chosen for the same data, thesegments would change to points 1–512, points 256–768, and points
513–1024. The 50% Overlap option (Welch’s method) better
approximates the moving average of the selected data, by doubling thenumber of computations and overlapping the segments from which
spectra are computed. On the other hand, the extra calculations takemore time, and may slow things down if your computer is an older
model.
Selection. There are two choices in this pop-up menu. The Use Current
option brings the total data points in a selection to a multiple of the FFT
size by padding the data with zeroes (adding points with a value ofzero) on the right-hand side.

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The Adjust to Best Fit option adjusts Spectrum’s ‘internal’ data selection
so that it is a multiple of the FFT size, by extending (symmetrically, if
possible) the data points selected for use within the same block. Notethat the visible selection in the Chart window is not altered, only
Spectrum’s internal data selection, so care must be taken when using
this feature.
Display. Spectrum can calculate various forms of power or amplitude
spectra: you can choose which is shown from the Display pop-up menu.
Details on how these are computed are given later. In each case, theheight of the spectrum at a particular frequency is representative of thepower or amplitude contained in the waveform at that frequency.
Appropriate units are shown in the axis labels.
Spectrum displays the results of the discrete Fourier transform in various
ways. The Power spectrum is basic; other forms are derived from it. The
power in a ‘bin’ of the spectrum is the modulus squared of the discrete
Fourier transform at that frequency. The amplitude in a bin is theamplitude of a sine wave whose average power is the same as thebin’s power. Power and amplitude values are always positive or zero;
they cannot be negative.
Power Density and Amplitude Density show the power or amplitude perunit frequency. Density is calculated by dividing the computed values
by the width of each horizontal frequency bin (this width narrows as thefrequency resolution increases and a greater number of discrete
frequencies are recognized). The units of power density are (y-axis
units)2/Hz, and the amplitude density units are (y-axis units)/√Hz.
The Log of Power and Log of Amplitude options show the power andamplitude spectra as log10 values. The logarithmic display makes
discernible smaller components that might otherwise be difficult to seein the graph because of the wide range of values.
The Power Attenuation and Amplitude Attenuation options give alogarithmic display showing the relative attenuation of spectral lines
with respect to a reference value (Pmax for a power spectrum, Amax for
an amplitude spectrum). The reference value is always taken as thelargest value in the spectrum and shows as 0 dB. Power attenuation is
calculated as dB = 10 log10(Pi /Pmax), and amplitude attenuation as dB= 20 log10(Ai /Amax), where Pi is the ith power component and Ai is
the ith amplitude component.

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Display As. FFTs are often drawn as bar graphs, with a vertical line orbar for each data point. You can use this pop-up menu to display the
FFT as lines, bars, or connected points, to suit the waveform or personal
taste. The Waveform Cursor will track the left edges of bars, whenthese are displayed.
Lines

Bars

Connected Points

Figure 6–12
A spectrum displayed aslines, bars andconnected points.

Remove Zero-Frequency Component. This option removes any zerofrequency value (that is, the DC offset, or the average value of theoriginal data) from the data before the spectrum is calculated. The
checkbox is on by default since the zero-frequency component often has
the largest amplitude of all components in a spectrum, and is usuallyunimportant. Click the checkbox to turn it off or on.

▼ Refer
Using Exclusions,p. 123

Exclusion Aware. Chart data can be marked with exclusions — points
or areas to be excluded from analysis for various reasons. By default
the Exclusion Aware checkbox is on and Spectrum takes exclusions into
account, ignoring excluded data. In this case, exclusions are treated as
separate blocks containing no valid data. Thus a spectrum will not becalculated for a selection lying wholly within an exclusion, and if a
selection intersects with an exclusion, only the left-most unexcluded data
will be used. If the checkbox is turned off, Spectrum ignores exclusions
and treats all data as valid.

Data Pad Functions▼ Refer
The Data Pad, p. 136

As well as calculating and displaying spectra in the Spectrum window,
you can also log parameters based on calculated spectra to the Data
Pad. Spectrum Data Pad functions are discussed in the Data Pad
section of this chapter.
Any changes made in the Spectrum Settings window will affect theSpectrum Data Pad functions.

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Chart SoftwareComputed Input
Often some computation based on raw signal data may be of moreuse, or may be required in addition to the original signal. For example,
if you have an oscillating signal it may be of use to show a trace of theperiod or frequency of the oscillations, or you may want an RMS
calculation of a vibration signal, or to plot the differential (rate ofchange of the signal. Chart has a number of powerful computed input
functions that allow the online processing of raw signals.

Figure 6–13
The Computed Input
dialog box — click OK
to apply the changes tothe channel in the Chart
window.

The Computed Input dialog box (Figure 6–13) lets you process signals
as they are recorded, converting the raw data from any e-corder input
into computed data. Both raw and computed data are displayed there,
for optimal settings adjustment. The dialog box appears if you choose
Channel Function pop-up > Computed Input… for a channel, or click
the Computed Input column in the Channel Settings dialog box. The
channel is indicated in the dialog box title. To set up many channels
quickly, click the arrows by the dialog box title, or press the right or left
arrow keys on the keyboard, to move to the dialog boxes for adjacentchannels. This skips channels that are turned off. Click OK to close thedialog box afterwards.

Choose the raw data input here after acomputed function has been chosen

Choose a computed function here

Sensitivity
controlThresholdcontrol

Signal tracking
controls (fortriggering
Ratemeter andso on)

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▼ Refer
Channel Settings, p. 81

The Computed Input… command from a Channel Function pop-up menu
is ticked if the channel has computed input applied. You can easily
check all the channels at once to see the computed function applied, if
any, by looking in the Computed Input column of the Channel Settings
dialog box.
The Computed Input dialog box has two main areas: the left side shows
the signal display for the raw data (similar to that in the Input Amplifier
dialog box), and the right shows the signal display for the computed
data. Initially the right display is gray, and few controls appear; if
something other than Raw Data is chosen from the Computed Function
pop-up menu, then computed input is active, the computed signal isshown in the right signal display area, and more controls are available.
Different functions may have different controls.

Sampling Rates
You might have to reduce the sampling rate or turn off channels tosample when using computed inputs, since they can use a lot of thee-corder’s processing power. Chart will give an alert if the sampling
rate is too high for your setup. All computations are done on raw datataken at 2000 samples per second or higher in the e-corder and thenprocessed to give derived values at the sampling rate set in Chart (thismeans that if you choose a sampling rate of 2000 /s or slower,
computations use raw data sampled at 2000 /s, and if you choose asampling rate above 2000 /s, computations use raw data sampled at
the set rate). The sampling rate you can set is limited by the number
and type of computed inputs chosen (since different functions use
different amounts of processing power), as well as the computer andthe connection.

Signal Displays
The raw and computed data are displayed so that you can see theeffect of changing the settings. No data are actually recorded whensetting up computed input, although stimuli can be generated while thedialog box is open (so that Stimulator output waveforms can beobserved). The current signal value is displayed at the top left of eachdisplay area. Slowly changing waveforms will be represented quite
accurately, whereas quickly changing signals will be displayed as asolid dark area showing only the envelope (shape) of the signal formed

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Figure 6–14
The computed data
display area with an
integral function selected.

by the minimum and maximum recorded values. You can shift andstretch the vertical Amplitude axis of each signal display to make thebest use of the available display areas. Apart from being at the right,
each is the same as the Amplitude axis in the Chart window, and thecontrols function identically.

Raw Data Controls
By default, Chart channels record the raw data for the corresponding
e-corder inputs. When first turned on, higher-numbered channels withno matching physical inputs record the Ratemeter computed function
based on the raw data of e-corder Input 1.
The Raw Data Input pop-up menu lets you choose any e-corder input as
the source signal upon which computations are performed. This meansthat raw data from any e-corder input can be processed and thecomputed results displayed on any channel. You can show raw data on
one channel and computed data on another, to compare them, or use
several channels to show various computations based on raw data fromthe same input. It is even possible to show the raw data from one input
on the channel corresponding to another input, although this could be
unnecessarily confusing in practice. Note that whenever you record
computed data in a channel, you replace any raw data that would
otherwise have been recorded there, so any original signal in thatchannel would be unavailable for further analysis.
Clicking the Input Amplifier… button opens the Input Amplifier dialog
box, allowing convenient access to filtering options, the display offset,
and so on for the raw data signal. The Range pop-up menu lets you
select the range of the input to get the best signal response. Changing
the range in this dialog box is equivalent in all respects to changing itin the Chart window: the pop-up menu is duplicated here forconvenience.
The Threshold and Sensitivity and the Baseline Tracking controls areavailable when one of the cyclic rate functions (Ratemeter, Period,
Frequency, and Counter) or cyclic amplitude functions (Cyclic Mean,
1/3Max+2/3Min, Cyclic Minimum, Cyclic Maximum and Cyclic
Height) is selected.

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Threshold and Sensitivity
Threshold control

Sensitivity control

The Threshold control sets the minimum level at which the signal will
trigger the computed input for a cyclic rate or cyclic amplitude function.
The incoming signal must cross through the threshold level in order toregister an event. The Sensitivity (or hysteresis) control allows you toadjust how sensitive the trigger is to small signal fluctuations.
The Threshold control is initially set to zero: if the signal has a lot ofnoise in this region, it is best to move the trigger away from zero. You
can drag the Threshold control up or down to change its settings — agray box and line appear, to indicate where it will go. When the box
and line are in the desired position, release the mouse button to apply
the new settings. The Sensitivity control is automatically moved with theThreshold control. It can itself be dragged up to adjust the sensitivity
bandwidth symmetrically above and below the threshold level —again, a gray box and line appear. When the box and line are in thedesired position, release the mouse button to apply the new settings. A
highlighted area indicates the hysteresis region. For a signal to trigger
the computed input function, it must go above the highlighted area andcross back through it: a signal remaining within the region will not
trigger the computed function.
Once the incoming signal is stabilized for cyclic rate and cyclic
amplitude functions, a threshold and hysteresis should be defined.
Because the signal is periodic for functions where this applies, it doesn’t
matter in many cases where the threshold is, because it will occur in thesame place in each cycle. It is best to move the threshold if there is a lotof noise around zero, though, or if the repeating waveform has multiple
peaks.

Figure 6–15
Using the Sensitivity
control to stop noise
triggering the computed
input.

Valid trigger pulse

Hysteresis region

Noise

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Baseline tracking is used to remove any constant or slowly changing
signal from the raw data before computed function triggering occurs. In
effect, it acts as a variable-frequency high-pass filter, ensuring that thethreshold and sensitivity settings follow the waveform. It works byapplying a suitable averaging technique to the raw data andsubtracting the result to modify the signal. The amount of averaging
depends on the position of the Baseline Tracking slider (Slow gives alittle, Fast gives a lot). Modified data are shown in the data display.

Figure 6–16
Applying a suddenchange to the input
signal at slow and fast
tracking speeds.

Data limit
area

Slow tracking

Fast tracking

Figure 6–16 shows the differences at slow and fast tracking speeds
when applying a sudden change to the input signal. The signal isoutside the trigger band for much longer with a slow tracking setting.
When using faster baseline tracking settings, the shape of the signal
may become distorted, but because data are only being used fortriggering when baseline tracking is available, the distortion does notaffect calculation accuracy. Figure 6–17 shows the distortion of asquare wave with a fast tracking setting.

Figure 6–17
A square wave (left)
distorted at fast tracking
speeds (right).

Data limit
area

The gray data limit area that can appear at the top and bottom of thedata display area indicates the full scale of the e-corder input at thecurrent range setting. If the gray area moves down and meets thesignal, the input amplifier is overloaded (this is the same as having thesignal go off scale in the Input Amplifier dialog box). If this occurs,
select a higher input range value. In general, the baseline tracking rate
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should be set as fast as is possible without decreasing the reliability oftriggering. Baseline tracking also has an Off setting, so it can be turned
off. This is useful where tracking the waveform could becounterproductive: say, when recording a digital pulse.

Computed Input Controls
Figure 6–18
The Computed Function
pop-up menu.

The Computed Function pop-up menu gives the range of available
functions. Raw Data means the sampled data with no computed
function applied, and is the default setting. The other functions are in
related groups: cyclic rate (Ratemeter, Period, Frequency and Counter);cyclic amplitude (Cyclic Mean, 1/3Max+2/3Min, Cyclic Min, Cyclic
Max and Cyclic Height); absolute value (Abs Smoothed and RMS
smoothed); envelope (Envelope Min and Envelope Max); and calculus(Differential and the five forms of Integral: normal Integral (∫), ∫Absolute Value, ∫ Positive Only, ∫ Negative Only, and ∫ Reset Each
Cycle). The functions are discussed in detail below.
The Units and Range controls are available when one of the cyclic rateor calculus functions is selected, and the Average control is available
when Ratemeter, Period, or Differential is selected. The Time controls
are available when one of the integral functions is selected, with the
exception of ∫ Reset Each Cycle, and the Reset control is available forall of the integral functions.
Clicking the Units… button opens the Units Conversion dialog box,
letting you change the given units for the computed channel to the unitsof your choice. The waveform in the right data display area istransferred to the data display area of the Units Conversion dialog box,
if you do this. The conversion will only apply to subsequently recorded
signals, so it is more limited than choosing units conversion directly,
since you cannot convert individual blocks of data. Units conversion is
performed on the computed data, not the raw data.
The Range pop-up menu lets you select the range for the computed
signal to get the best display. This range applies only to the computed
signal, and is independent of the range for the raw data signal from thee-corder input. The Range pop-up menu for a channel in the Chart
window duplicates this one when the computed function is applied tothe channel, and the range can be changed in either place.

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The Average control allows smoothing of the data when you want tosee a trend in a Ratemeter or Period waveform rather than sample-bysample changes. Click the up or down arrows to increase or decrease
the averaging: the sequence is 1, 2, 4, 8, with 1 being no averaging.
The Average control is also available for the Differential computed
function, with the sequence reaching 64. The control works byaveraging the values of the specified number of preceding samples,and so may give rise to a slight phase shift in the waveform, especiallywith the Differential function. If you need to know exact times, you
should record the raw data separately as well.
The Time controls let you choose how an integral function resets tozero. For periodic waves, resetting corrects for cumulative errors, suchas those due to DC offset. If No Reset is chosen in the pop-up menu, thetext box is dimmed and inactive; otherwise you can enter a value of up
to 3600 seconds for Timed Reset or 65 seconds for Time Const, inincrements of the sampling interval (0.1 seconds if you sample at 10
samples per second, say). Timed Reset resets the signal to zero after
each multiple of the entered time. Time Const introduces an exponential
decay, so that (given a zero input signal) the integral drops to 37% of
its initial value over the set time.
The Reset button resets the signal in the computed input data display
area to zero when clicked. It is only used for convenient zeroing of thedisplay signal while in the dialog box.

Computed Input Functions
Ratemeter
Frequency, or rate, is how often a given event occurs within a certain
time. The Ratemeter function measures lower-frequency periodic signals
and gives the output in reciprocal minutes (BPM, beats per minute) up
to 2000 BPM. The Ratemeter function first calculates the waveformperiod (see below) and then takes its reciprocal and scales it
appropriately.
Since the period is the difference between valid triggering signals, if
triggering is lost, then the period will get larger. In this case, the period
is constantly updated to show that it is currently at least a certain
length. The computed signal thereupon falls exponentially (since it is

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Figure 6–19
Ratemeter: left, the raw
data showing periodic
pulses; right, thecomputed ratemetersignal in BPM.

Figure 6–20
Loss of Ratemeter
triggering signal: left,
raw data; right,
computed input.

Figure 6–21
Period: left, raw data
(showing two thresholdsettings, either setting
would work well); right,
computed period signal.

PeriodPeriodThe Period shows the period variations clearlybased on the reciprocal of the period), which gives an indication thattriggering has been lost: if just a straight line were presented,
continuing to show the last valid rate, it might be assumed incorrectlythat things were still all right.

PeriodA period is the time taken to complete one cycle of a regularly
recurring waveform. The Period computed function is basically theRatemeter without the reciprocal, and gives information about the160

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periodic behavior of a waveform. Note that the measurement is
independent of where the trigger point is in the cycle.
The period is the difference between valid triggering signals, so if
triggering is lost, then the period will get larger. In this case, the period
is constantly updated to show that it is currently at least a certain
length, and will increase until the maximum period for the set range isreached. Period can be more a useful measure than frequency forwaveforms with very slow cycles, such as waves in water or tremors inearth.

Frequency
Frequency is how often a given event occurs within a certain time. The
Frequency function measures the frequency of the waveform in hertz(cycles per second) up to 2000 Hz, and is suitable for measuring
periodic signals of higher frequency than those for which the Ratemeteris used. The calculation is done differently to that for the Ratemeter, toensure accuracy. The Frequency function works by breaking eachsecond into 20 ‘bins’. Each time the threshold is crossed from lower tohigher, the count in the current bin is increased by one. (That is, itcounts the number of times the signal crosses the threshold in one
direction every 0.05 s.)Chart shows the sum from the last 20 bins. This gives a faster andsmoother result than if summing were just done for one second. For
example, if recording a 100 Hz signal that changed to 200 Hz over
one second, you would see the frequency gradually changing from 100
to 200 Hz. If results were summed over one second, you would just see
a jump from 100 to 200 Hz, with an intermediate value (the averageof the two signals).
Change from 100 to 200 Hz

Change from 100 to 200 Hz

Figure 6–22
Frequency: left, thegradual change used byChart, right, if summation
were coarser.
1 second

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1 second

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Counter
The Counter function just counts transitions from below to above thethreshold, displaying up to 20 000 registered events versus time. It
wraps back to zero when it gets to the maximum number of counts inthe current range. If you set the range to 200, for example, then after
the count reaches 199, the waveform will reset, so that the next, 200th,
count will be 0 again. This lets you quickly get a total count over a timeby looking at the number of resets, plus the last number shown for thecount. This function has a number of useful purposes, for instancetallying the radiation blips registered by a Geiger counter.

Cyclic Mean
A cyclic mean is the average amplitude of a waveform over a cycle.
Variations indicate some form of asymmetry. The Cyclic Mean function
sums the values of the data points between two successive threshold
transitions and divides by the number of points summed. Note that thiscalculation is only useful for truly cyclic (oscillating) signals, it should
not be used to try to determine the mean of a noisy signal. The
threshold controls where the summation starts and ends, but because
the input is a cyclic wave, the result should not depend on thresholdposition. Only when the waveform has some other periodic signal
superimposed on it does the actual threshold affect accuracy of
calculation. The results you get from the cyclic mean are the same as if
you selected an exact period of the raw data, integrated that selection,and divided the integral by the period.
Note that in Figure 6–23, summing starts and ends at different times
when the threshold is in different places, but the results are the same. It
would be much better in this case to leave the threshold in the center ofthe waveform, because it will still work even if the amplitude of thesignal changes slightly. In the right-hand example, if the amplitude weremuch smaller, the triggering would be lost.

Figure 6–23
Cyclic Mean: summed
area for different
thresholds (shown
shaded).

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1/3Max+2/3Min
The 1/3Max+2/3Min function adds, for each cycle, one third of the
maximum amplitude of the waveform to two thirds of the minimum, togive an approximate mean and is included for historical purposes. A
more accurate mean is obtained using the Cyclic Mean computed
function.

Cyclic Max, Min, and Height
In the Cyclic Max function, the trigger threshold identifies cycles. At theend of a cycle, the maximum data point found within that cycle isshown until another cycle has been measured. The Cyclic Min function
works similarly, save that the minimum value of a cycle is found, anddisplayed during the next cycle. The Cyclic Height function determines
the maximum minus the minimum value. These functions are useful forshowing the cycle-by-cycle minima or maxima or the difference
between the two.
Maximum from previous cycle

Figure 6–24
Cyclic Max: the largest
value obtained by the
waveform in the previous
cycle is retained.

perio

Abs and RMS Smoothed
Abs Smoothed smooths using the absolute values of the preceding data
points over the time set in the Smooth pop-up menu. RMS Smoothed(root-mean-square) smooths using the square root of the average of thesquared values of the preceding data points over the time set in the
Smooth pop-up menu. (In each case, the data points are sampled at2000 samples per second or faster.) These two functions provide
similar ways of getting the same thing, a modified moving average, set
by time, not by number of samples, and ignoring whether peaks are
positive or negative (that is, regardless of whether the waveforms are

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163biphasic). They are useful in electromyography and studies of
spontaneous neural activity, to provide an indication of the averageamount of activity.

Envelope Max and Min
Envelope Max finds the maximum value of the data points over the time
between samples at the sampling rate set by the user, and displays it
during the next time period. Remember that the e-corder always
samples data for computed input at least 2000 samples per second,even if the apparent rate is much less. If you set a sampling rate of one
sample per second in Chart, then the maximum value of the samples in
the previous second would be shown each second in the display.
Information is not required about cycles or periods in the incoming
data, so the triggering controls don’t appear.
Maximum from time between previous e-corder samples

Figure 6–25
Envelope Max: sample
times are independent of
the waveform period —note that the raw
sampled data, shown as
open circles, could bequite misleading in thiscase.
sample times

Time between samples

The Envelope Min function works similarly except that the minimum
value over a time is found, and displayed during the next time period.
These functions are useful if the specifics of the signal are of no interest,
but the maxima or minima are important, since they let you record at amuch lower sampling rate than would otherwise be the case. As you
can see from Figure 6–25, you would need to record at a far higher
rate to get an accurate depiction of the waveform. These functions
could be used, for instance, to record the maximum and minimum
amplitudes of a oscillating signal: no additional information is gainedby sampling these more than once per oscillation.

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Chart SoftwareDifferential
The Differential function gives the first derivative with respect to time ofa selected channel’s waveform. It is useful when the slope, or rate ofchange, of a signal is more informative than the raw signal itself. For
example, the volume of fluid in a container could be weighed as it iscollected, using a force transducer. The differential of this plot would
give the rate of change of volume, that is, the flow rate.

Figure 6–26
Differential: thederivative of a triangularwave (left) is simply asquare wave (right).

This function is particularly sensitive to noise, so the data smoothing
provided by the Average control has been extended beyond thatoffered for Ratemeter or Period functions, with your choice of 1, 2, 4,
8, 16, 32 or 64 preceding samples being averaged. (Note that thismay give rise to a slight phase shift in the waveform.)

Integral
The Integral measures the area under a waveform, calculated as thesum of the data points multiplied by the sample interval. You could
integrate the signal from an instrument that measures flow rate tocalculate volume, for instance.
Figure 6–27
Integral: the integral of asquare wave (left) is
simply a triangular wave
(right).

Five types of integral function are available, each useful for a different
purpose.
∫ (Integral). This, the normal integral, is simply calculated as the sum of
the data points multiplied by the sample interval. The integral over timeof a signal with equal positive and negative summed values would be
zero.

Chapter 6 — Data Analysis

165∫ Absolute Value is calculated as the sum of the absolute values of thedata points multiplied by the sample interval. The integral over time of asignal with equal positive and negative summed values would be
double the summed values of either.
∫ Positive Only is calculated as the sum of the positive values of thedata points multiplied by the sample interval. The integral over time of asignal with positive and negative data points would only include thesummed values of the positive data points.
∫ Negative Only is calculated as the sum of the negative values of thedata points multiplied by the sample interval. The integral over time of asignal with positive and negative data points would only include thesummed values of the negative data points.
∫ Reset Each Cycle, like the normal integral, is calculated as the sum of
the data points multiplied by the sample interval. The integral over timeof a signal with equal positive and negative summed values would be
zero. This function also, however, resets the integral to zero every time
the original waveform passes from below to above zero, so it isparticularly useful for periodic waveforms subject to drift (with an
uncontrolled offset voltage).
Resetting helps to compensate for drift that might otherwise take an
integrated signal off the scale. All integrals reset to zero when theyreach the positive or negative limits set by the Range control. The∫ Reset Each Cycle resets the integral each time the original waveform
passes through zero from below; other forms of integral reset the
integral as specified in the Time controls. The reset effectively subtracts
the range whenever the range is exceeded, so you can count the
number of resets to get the total value.
Raw signal

Figure 6–28
A steady offset, and its
integral, using two formsof resetting.
Integral with timed reset

Integral with time constant

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Times entered in the text entry box smaller than the sampling interval
may round down to zero, in which case no resets occur. Values should
be longer than the interval over which integration is desired, in any
case. ∫ Timed Reset resets the signal to zero after each multiple of theentered time. This method copes with drift, and computes an accurate
integral before the reset. ∫ Time Const introduces an exponential decay,so that (given a zero input signal) the integral drops to 37% of its initialvalue over the set time (up to 65 seconds). This avoids drift and sudden
resets, but the resultant integral will be inaccurate: this inaccuracy
increases as the time constant gets smaller.

Channel Calculations
The options in the lower half of a Channel Function pop-up menu allow
you to apply calculations to channels of recorded data. No Calculationis the default setting, and means the displayed data in the channel arerecorded data (either raw data or computed data) with no extra
calculation applied. The Smoothing, Arithmetic, Cycle Variables,
Differential and Integral calculations are built into Chart, and aredescribed here. Other channel calculations may be added with Chart
extensions. Channel calculations may be online (you see the results as
you sample) or offline (you see the results of the calculation only after
sampling finishes).

▼ Refer
Channel Settings, p. 81

To turn on a channel calculation, choose its menu command from a
Channel Function pop-up menu. To revert to the data recorded in achannel (if any) choose No Calculation. A tick beside the option shows
which is active: only one can be at any time. Calculations apply to theentire length of the channel, and operate on the displayed data of thesource channel (Arithmetic can also operate on underlying recordeddata). You can turn off a channel calculation without losing the values
you enter in its dialog box. You can easily set up many calculations at
once, or check all channels at once to see if any calculations areapplied, by using the Calculation column of the Channel Settings dialog
box.
If a channel calculation is applied to a channel, an = sign appears in
the Channel Status indicator (the diamond at the right of the channel’s
Range/Amplitude display). Clicking the indicator pops up a list

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showing the sampling rate, range, what is to be recorded (raw data or
a computed function, and from which input), and any active channel
calculation.
Common to most channel calculation dialog boxes is a source pop-up
menu, which lets you choose the waveform in any Chart channel as thesource to be processed. You may want to use one channel to display
the source signal, and another to display the calculation, forcomparison between the two. To display only the calculated signal, you
would choose the same channel for the source as for the display.
The calculation for a channel calculation is generally done when its
dialog box is closed. Quite often, you might want to adjust somesettings (such as the degree of smoothing) repeatedly and observe theeffect on a waveform. This requires bringing up the dialog box eachtime you do it, so a keyboard shortcut has been provided to ease theprocess and avoid the stress of a long trip to the pop-up menu. The
latest calculation to be applied in the Chart window (Smoothing in
Channel 4, say) gains a keyboard shortcut, Command-=, whichappears beside it in its Channel Function pop-up menu: just typeCommand-= to recall the dialog box. If No Calculation is chosen, no
keyboard equivalent appears, and any existing one is dispelled.

Channel Calculations and Exclusions▼ Refer
Comments andExclusions, p. 117

Exclusions are a special type of comment that mark data to be excluded
from searches and analysis. All the channel calculations built into Chart(Smoothing, Arithmetic, Cycle Variables, Differential and Integral) do
not recognize exclusions, and make the same calculation whether or
not they are present. Channel calculations added by Chart extensions
vary in their handling of exclusions: check their accompanying
documentation for details.

Channel Calculations and Computed Functions
There is some overlap between computed functions and channel
calculations: which is best in a situation depends on the data and what
you want to do with them. Computed functions must be chosen before
sampling is started, and can apply to individual blocks of data.
Channel calculations can be turned on or off as required, and always
apply to the entire length of the channel in which they are active. They
can be applied before, during, or after sampling, and can be used to168

Chart Software

analyze data recorded at faster rates than possible using computed
inputs, which use some of the e-corder’s processing power. Channel
calculations do not replace the recorded data in a channel, and can beused in channels that are turned off. They are useful when you need toretain the raw data as well as manipulate it in some way, and don’t
have enough channels to do everything at once. Some calculations
work online and offline, but the more complex ones tend to be offline
only, so you can’t see results as you sample. Computed functions arealways online, so that you can see results as you record.

Table 6–1
Comparing computed
input with channel
calculations.

FeatureComputed Input

Channel Calculation

Results visible during
sampling

Yes

Simpler ones, yes;others, no

Raw data retained

Only if recorded onanother channel

Yes

Can be applied after
sampling

No

Yes

Channel can be off

No

Yes

Can record at thehighest sampling
rates

No

Yes

In addition to differences in the way computed inputs and channel
calculations are used, there may also be differences in the accuracy
and precision of the results of corresponding computed functions andchannel calculations, such as integral and rate computations. Details
are given in Appendix C, but the following general rules apply:•

When computations rely on a window of points, channel
calculations have a greater accuracy than the corresponding
computed input functions; otherwise accuracy will be the same.

•If the sampling rate is < 2000 Hz, computed input functions have agreater precision than the corresponding channel calculations;otherwise precision will be the same.

Hidden Data
If a channel contains recorded data and channel calculations for thatchannel are turned on, its displayed data will be the calculated data.

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The recorded data (either raw data or computed data) still remain
underneath, and can be seen simply by turning the calculation off.
If the display in a channel uses calculated data from other channels, awarning icon flashes in the channel control area to the right of theRange/Amplitude display, on top of the Channel Status indicator. Thisis a reminder that what you see in the channel is not necessarily what
you are recording on that channel. If you click the icon, an alert box
tells you the area of concern (in this case, that the channel has recorded
data hidden by calculated data from other channels). If the calculation
for a channel manipulates any data from the channel (even if data fromother channels are included), then there is no warning icon or alert,since the data must bear some direct connection to the recorded data.
The icon and an appropriate alert may appear at other times, such as
when a calculation in a file was set with a Chart extension no longer
present.
Channel calculations normally work on the displayed data in achannel, so you can use them in sequence. For instance, you could
smooth a waveform in one channel using the Smoothing calculationand then show the log of that smoothed waveform in another using theArithmetic calculation. Some calculations, such as Arithmetic, let you
choose to work on the underlying recorded data of a channel as analternative to the displayed data.

Applying Calculations Permanently
Channel calculations are usually temporary, and can be created anddiscarded at will. You can, however, apply a channel calculation
permanently to a channel, so that the calculated data become therecorded data for the channel. Beware! This replaces any recorded
data already in the channel. Once gone, such original data cannot be
retrieved, so an alert box will ask you to confirm your decision. When
applying calculations like this, it is a good idea to use channels with norecorded data in them or to work with a copy of the original file.
To apply a calculation to a channel, hold down the Command key
while opening the channel’s Channel Function pop-up menu, andchoose the Apply Calculation… menu command that replaces the No
Calculation menu command: the calculation is applied, subject toconfirmation through the alert box. The calculated values effectively
then become the recorded data. If no channel calculation is active in

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Chart Softwarethe channel, the Apply Calculation… menu command will be dimmed
and unavailable.

Smoothing
The Smoothing calculation lets you remove unwanted high frequencies,
noise, or clutter from a waveform. Smoothing always operates on thedisplayed data of the source channel. This in turn may have been
calculated by another channel calculation (such as Arithmetic). The
Smoothing channel calculation is offline, so you can see the smoothed
data only when Chart is not sampling (during sampling, you see any
recorded data).
Choosing the Smoothing… command from a Channel Function pop-up
menu opens the Smoothing dialog box for that channel.

Figure 6–29
The Smoothing dialogbox.

Any channel’s data can be chosen to be smoothed
Increasing the width of the averaging increases thenumber of points used to smooth the waveform

Figure 6–30
The effects of smoothing
on a waveform.

Original waveformwith no smoothing

Smoothingwidth of 3

Smoothingwidth of 5

Smoothingwidth of 9

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By default, the channel in the dialog box title is chosen in the Sourcechannel pop-up menu, but you can choose any channel as the source
signal to be processed. If you want to display both the smoothed andthe recorded data, to compare them, you could apply the function to anunused channel, leaving the source recorded data channel intact.
Smoothing works by taking a certain width of data, the sample point
and an equal number of points on either side, weighting the points
suitably, and averaging them to give the smoothed value for the sample
point. The points are weighted using a triangular (Bartlett) window, sothat the central point affects the result more strongly, with points further
out affecting the result less and less. (For 3-point smoothing, the central
point would be weighted by 1/2, and the two points beside it by 1/4;
for 5-point smoothing, the central point would be weighted by 1/3, thetwo points beside it by 2/9, and the two outlying points by 1/9; andso on.) This is a modified moving average that avoids phase shift, anddoesn’t smooth or smear the waveform as much as simply averaging
together a number of points.

Figure 6–31
The Arithmetic dialog box— click OK to show thefunction in the display
channel in the Chart
window.

The width is always an odd number. Click the up and down arrows toincrement or decrement the number, or type in the number of points,from 3 to 201, in the text entry box. At the start and end of the
waveform, fewer points can be taken on one side, so the number ofpoints used in the average decreases at the extremes.

Select afunction

Expression
text entry
box

Select achannelSet theAmplitude axis
scale manually

Set the scale
automatically172

Enter units for the calculated channel

Chart Software

Smoothing affects different waveforms in different ways: quickly
changing waveforms cannot be smoothed too much without distortion,
but those that change slowly can be smoothed a lot more.

Arithmetic
The Arithmetic calculation allows you to arithmetically combine
waveform data from different channels. It works online (during
recording) as well as offline. Choosing the Arithmetic… command froma Channel Function pop-up menu opens the Arithmetic dialog box. The
channel from which the command is chosen, and in which results will
be displayed, is indicated in the dialog box title.

Entering an Expression
To enter an expression, click in the expression text entry box and type,or click the various buttons and choose channels and functions from the
pop-up menus. For channel data, type ‘Channel1’ or ‘Ch1’ and so on(case is unimportant, but no spaces should be used), or choose achannel from the Channel pop-up menu. For functions, choose afunction from the Function pop-up menu, or type the text of the function
as it appears there (case is unimportant). Any combination of channels,
functions, and operations can be entered. The normal order ofoperations applies, and brackets should be used as appropriate:
4*9+6 gives 42; 4*(9+6) gives 60. If you enter a simple arithmetic
operation (say, 4*9+6) without references to channel data or time, youwill get a straight line in the channel logging the result.
By default, Arithmetic operates on the displayed data of the channels
you specify. The data in these channels may be calculated by otherchannel calculations (for instance, smoothing may have been applied).
You can choose to work on the recorded data of an input channel,
ignoring any other calculations that may be active, by typing ‘R’ before
the channel expression (‘RChannel1’ or ‘RCh1’), or choosing a channel
from the Recorded Data submenu in the Channel pop-up menu. The
recorded data is the signal that comes from the e-corder to Chart before
any channel calculations are applied, and can be either raw data orcomputed data.

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Checking the Expression Syntax
When you click OK, Arithmetic checks to see if it can understand theexpression. If it cannot, an error message will be displayed. Possible
causes of problems are missing brackets or having nothing at allentered. Also, note that most functions that includes brackets, such as
Abs(), require an argument (that is, something to operate on) within thebrackets.

Math Functions
Basic mathematics functions (+ add, – subtract, * multiply, / divide) canbe entered by typing, using the buttons, or choosing from the Mathsubmenu of the Functions pop-up menu.

Trigonometric Functions
Trigonometric functions can be chosen from the Trig submenu of the
Functions pop-up menu. Sin(), Cos(), and Tan() return the sine, cosine,and tangent. These functions expect an argument in radians.
ASin(), ACos(), and ATan() return the arc sine, arc cosine, and arc
tangent, that is, the angle whose sine, cosine, or tangent is equal to thegiven value. These functions are the inverse functions of sine, cosine,and tangent. The result is expressed in radians. ASin() and ACos() needarguments from 1 to –1 inclusive (since sine and cosine produce novalues outside those limits), so you may need to scale data to fit.
DegToRad() converts degrees to radians, and RadToDeg() converts
radians to degrees (2π radians is equal to 360 degrees).

Logarithmic Functions
Logarithmic functions can be chosen from the Logs submenu of the
Functions pop-up menu. Log10() returns the base 10 logarithm of anumber. Ln() returns the natural, base-e, logarithm of a number. The
constant e equals approximately 2.7182818. Exp() returns the
exponential of a number, that is, ex (e raised to the power of theargument). The exponential is the inverse function of the natural
logarithm.

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Noise Functions
Random() returns random numbers from a uniform distribution between–1.0 and 1.0 inclusive. Gaussian() returns random numbers from anormal distribution with a mean of 0.0 and a variance of 1.0.

Other Functions
The function Sign() returns the sign of a number, that is, Sign(x) = 1 if x
≥ 0, –1 if x < 0. Abs() returns the absolute value of a number, that is,
negative numbers are made positive. Sqrt() returns the square root of anumber (the square root of a negative number returns zero).
Pi returns the constant π, approximately 3.1415927, when used in an
expression. SampleTime returns the time in decimal seconds from thestart of the data block.
Round() rounds a number to the nearest whole number (0.5 rounds up).
Int() returns the integer part of a number, truncating any fractional part,
regardless of sign. For instance, Int(2.999) will return 2.

Units and Scaling
If units conversion is applied in a channel used in an expression,
Arithmetic ignores the units and just uses the displayed values in thatchannel for its calculations. Note, though, that the linear scaling
performed by units conversion may affect numeric values. For thisreason, you will be alerted if a channel used in an expression has
different units in different blocks. Units conversion does not work in achannel where the Arithmetic calculation is active. So that units can beprovided for a calculated channel where you want them, the Unit
Name text entry box lets you type in up to 10 characters for a unit
name. As with normal units, superscripts and subscripts can be used.
By default, the Auto Scale checkbox is selected, which causes
Arithmetic to estimate the most appropriate scale for the channel (whenthere is data to base a scale on). If channel data and operations are
unusual and the checkbox is deselected, a scale can be assigned
manually.

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You can type in directly the lower and upper limits of the scale to be
displayed, in the Top and Bottom text entry boxes. (This deselects theAuto Scale checkbox.) This option allows you to adjust the Amplitude
axis directly to display a desired range of values, just as you can with
the Set Scale dialog box, available from the Chart window. The scale
will affect the accuracy (in significant figures) of the displayed numbers.
Channel calculations in Chart use single-precision floating point
arithmetic, so results are accurate to six decimal places. The number ofdecimal places set in the dialog box, from 0 to 6, affects only thedisplay, not the internal accuracy of the calculation.

Using Unconverted Voltages
Data in volts, millivolts, or microvolts (with no units conversion applied),
are all dealt with by the Arithmetic calculation as volts. This means caremust be taken when using lower ranges, and when dealing with data
recorded at ranges with different orders of magnitude. Depending on
the data and the operations performed, the numbers calculated may bevery large or very small. They can be adjusted to be easier to use byusing a scaling factor in the expression.
If you recorded signals on the 10 mV range, for example, and used
Arithmetic to add a two such channels together, the results would be
expressed in volts, not in mV. To get a derived value in mV, you needboth to type ‘mV’ into the Unit Name text entry box, and to bracket thesum of the channels and multiply it by 1000: (Ch1+Ch2)*1000. This
scales the expression correctly.
In general, you have to work out what you want the results displayed inand apply an appropriate scaling factor to the expression: 1000 if thedata are to be in mV or 1 000 000 if the data are to be in µV. As
always, it is important to be sure about what you are looking at andcalculating.

Cycle Variables
Cycle Variables is a calculation for analyzing periodic waveforms.
Since it works offline, it can be used after recording, for analysis ofdata recorded at faster sampling rates than is possible using cyclic rateand cyclic amplitude computed input functions.

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Chart Software▼ Refer
Computed Input
Functions, p. 159

Choosing the Cycle Variables… command from a Channel Function
pop-up menu opens the Cycle Variables dialog box. The results will be
displayed in the channel indicated in the title bar.

Setting Up Cycle Variables
The signal display area in the dialog box shows the waveform for thesource channel. If a selection has been made in the Chart window,
data are shown over the approximate recording period of that selection(starting from the left edge of the selection, and using only the data in
the left-most block of a selection containing two or more blocks). If there
are too many trigger points in the selection, Cycle Variables limits thedisplay to show a sensible number. The duration of the displayed
waveform is shown in the bottom left of the signal display area. If there
is no selection, the data visible in the Chart window (or the largest
visible block if two or more blocks are visible) are shown. This
displayed waveform is used to set detection parameters, such as noise
threshold.
Whether the source signal is recorded or displayed data is shown inthe bottom right of the signal display area. Displayed data are simply
what is shown in the source channel, whether calculated, raw, orFigure 6–32
The Cycle Variables
dialog box — click OK to
apply the chosen function
to the display channel in
the Chart window.

Display channel

Choose the function to
be calculated here

Select thesourcechannelSignal display
area
Duration of
displayed
waveform

Chapter 6 — Data Analysis

TriggerpointsType of source
data, recorded ordisplayed

177computed. If Cycle Variables has been chosen as a channel calculationin the source channel, though, the dialog box will show recorded data
(raw or computed). This is because the detection parameter settings
apply to this underlying data and make no sense in relation to thecalculated waveform.
You can change the initial display by using the controls at the bottom of
the signal display area. The scroll bar lets you move through data in theChart window if the block used by Cycle Variables is not wholly
displayed. The box in the scroll bar shows where the display area is inrelation to the block. Drag the box to move left or right. Click the left or
right arrows to move left or right by 10% of the visible waveform; clickin the gray region to either side of the box to move left or right by 90%of the visible waveform. View buttons, like those in the Chart window,
let you compress or expand the data shown. To see more of the source
waveform, click the left (far mountains) button to compress it. To expand
the source waveform for a closer view, click the right (near mountains)button. Click the Reset button between the two to revert to the initialdisplay.

Cycle Detection▼ Refer
Find Data, p. 134

Cycle Variables detects cycles by finding local maxima and minima, in
a similar way to the Find command. Detected trigger points are marked
on the displayed waveform in the dialog box as small blobs. Whether
maxima or minima are used depends on which radio button in the
Trigger panel is chosen. This makes no difference to the method ofcycle detection, but may make a difference to the results, depending on
the waveform. (If, for instance, a waveform contains a well-defined
upwards spike and two similar downwards spikes in each cycle, itwould make more sense to trigger on the maximum.)
Detection parameters (noise threshold, triggering, tracking) apply to thedetection of all cycle variables in the same source channel. In otherwords, Cycle Variables will use the same parameters whenever it bases
calculations on that source channel. This is handy when you havemultiple channels showing various cyclic calculations for a single sourcechannel, since the detection parameters only need be set up or changed
once for the whole lot.

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Noise Threshold
The Noise Threshold control lets you adjust how sensitive the trigger isto small signal fluctuations. The noise threshold for the event is apercentage of the range of the channel (the default value is 5%, whichis 1 V for a ±10 V range). For a data point to be recognized as apeak, say, the data points that follow must decrease by at least thenoise threshold value. Peaks or troughs with smaller amplitudes than
this value will be ignored. Raise the value to get rid of unwanted small
peaks (noise and so on); lower it to detect missed peaks. The noise
threshold percentage can be set by using the text box or the slider bar.
When the noise threshold is changed, the trigger points, marked on thedisplayed waveform as small blobs, will shift after a short delay, so you
can see the effect of the change.

Tracking
In the case of a waveform with an amplitude that drifts significantly
over time, or a low signal-to-noise ratio, the usual triggering scheme
may run into difficulties. Tracking helps to solve these problems. The
Tracking pop-up menu in the Trigger panel is normally set to Off. You
can choose a tracking interval from this pop-up menu to turn tracking
on. The noise threshold is now taken to mean a percentage of the
maximum amplitude within the tracking interval rather than apercentage of full scale. (The noise threshold usually needs to be
increased relative to its normal settings when using tracking.) The
tracking interval is centered on the current data point, and moves alongas the detection algorithm is applied. This helps deal with changes in
the overall signal amplitude.
Even if the tracking interval has been set to less than or equal to thesampling interval, it will always be set wide enough to include at least

Figure 6–33
Adjusting tracking andnoise threshold to detectsignificant peaks in a
waveform of varying
amplitude.

Chapter 6 — Data Analysis

179three data points. Changes in amplitude of less than 5% of the current
data range are not tracked, so the range should be chosen so that data
are making reasonably good use of it. Note that tracking slows down
the Cycle Variables calculation a bit.

Functions▼ Refer
Computations with
Computed Input
Functions and Channel
Calculations, p. 261

The Function pop-up menu gives the list of cyclic variables that can becalculated. There are rate functions (Ratemeter, Period, and Frequency)
and amplitude functions (Cyclic Height, Cyclic Mean, Cyclic Maximum,
Cyclic Minimum, and 1/3Max+2/3Min). The functions are similar to
cyclic rate and cyclic amplitude computed input functions, but may giveslightly different results, for reasons explained in Appendix C.
The Default Scale pop-up menu lets you select the range of the channel
to get the best display of the calculated function. This menu is only
available when one of the rate functions (Ratemeter, Frequency, or
Period) is chosen in the Function pop-up menu. Changing the range inthis dialog box is equivalent to changing it in the Chart window. It isuseful if you know the approximate settings already; you cannot see theresultant waveform in the Cycle Variables dialog box as you can in theComputed Input dialog box.
Ratemeter. Frequency, or rate, is the number of times that a given event
occurs within a certain period. The Ratemeter function gives output inreciprocal minutes (BPM, beats per minute) up to 2000 BPM (about
33 Hz).
Period. A period is the time taken to complete one cycle of a regularly
recurring waveform. This function determines the period between
adjacent cycles in a waveform. The period is taken as the time between
two successive crossings of the threshold from higher to lower. Its
accuracy will depend on the number of samples taken during that time.
Period can be more a useful measure than rate or frequency forwaveforms with very slow cycles.
Frequency. Frequency is the number of times that a given event occurs
within a certain time. The Frequency function measures the frequency of
the waveform in hertz (cycles per second) up to 2000 Hz.
Cyclic Mean. A cyclic mean is the average amplitude of a waveformover a cycle. Variations indicate some form of asymmetry. The Cyclic

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Chart SoftwareMean function sums the data points between two successive peaks anddivides by the number of points. This is useful, say, for determining themean displacement of a vibrating object. The results you get from thecyclic mean are the same as if you selected an exact period of thesource, integrated that selection, and then divided by the period.

Figure 6–34
Source (top channel) andthe cyclic mean (bottom)
calculated from it, for a
block of data.

Calculations work fromthe first to last cycles ineach block

1/3Max+2/3Min. The 1/3Max+2/3Min function adds, for each cycle,
one third of the maximum amplitude of the waveform to two thirds ofthe minimum, to give an approximate weighted mean and is included
for historical puposes. A more accurate mean can be obtained using
the Cyclic Mean function.
Cyclic Maximum and Minimum. The Cyclic Maximum function displays
the maximum value found within a cycle. The Cyclic Minimum function
works similarly, except that the minimum value of a cycle is shown.
Cyclic Height. The Cyclic Height function calculates the difference
between the maximum value and the minimum value in a cycle.

Average
The Average control lets you set the number of cycles, from one to 50,
over which the chosen cycle variable is averaged. The average iscalculated over cycles after and including the current one, so if anaverage of four were chosen, the current cycle and the next three cycles
would be used. By default, the average is set to one. Click the up anddown arrows to increment or decrement the number, or type a value inthe text box directly. Averaging smooths fluctuations in the cyclic
variable, and is especially useful with erratic data. The number set in
the Average control must be substantially less than the number of cycles
in the data (perhaps less than half), or the values will not make sense.

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Display in the Chart Window
Once the controls in the Cycle Variables dialog box have beenadjusted, click OK to apply the calculation to the display channel in theChart window. The calculated variable applies to the whole channel,
but is calculated and drawn only as blocks become visible (else theprocess would take a long time for very large files). It draws from thefirst detected cycle to the last in a block. Where there is no sensible
value (such as at the very start and end of a block), the value of the plotis set to ‘Out of Range’.

Saving a Text File
A text file containing any or all of the cyclic variables associated with awaveform can be saved to disk. To save the text file, click the Save As
Text… button in the Cycle Variables dialog box. The Save Cycle
Variables as Text dialog box appears.
Select the checkboxes in the Include panel to include variables in the
text file to be produced. Just what part of the data is saved depends on
the radio button selected in the Save panel. Note that the Selection
option uses the selection as a guide only: Cycle Variables works fromthe left of the selected data, and may shift to the right to get a whole
number of cycles.
The standard text file created can be opened by any application that
can import text, such as a word processor, spreadsheet, or statistics

Figure 6–35
The Save Cycle Variables
as Text dialog box.

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package. The data for each cycle is stored as a row of numbers,
separated by tabs and ending in a return character. The first number ineach row is the time at which the cyclic transition was found. The timeis from the start of the block, and if you select the Always Seconds
checkbox, it will always be in seconds. The time is followed by one
result corresponding to each checkbox selected in the Save Cycle
Variables as Text checkbox. Because there is only one point per cycle
for the time and derived values, a text file of cycle variables data will
generally be a lot smaller than a text file of Chart data.
When you click OK, a standard Save As dialog box appears. Type ina file name as required and click the Save button to create the cycle
variables text file.

Data Pad Functions▼ Refer
The Data Pad, p. 136

Cycle Variables adds functions to the Data Pad. These functions are
similar to those available as channel calculations, and are based on thesame cycle detection settings. Cycle Variables Data Pad functions are
discussed in the Data Pad section of this chapter.
Any changes made to the cycle detection settings of the Cycle Variables
calculation for a particular channel will affect the Cycle Variables Data
Pad functions as well, and vice versa.

Differential
The Differential channel calculation calculates the first time derivative ofthe data in a channel. The calculation is offline, so you can see thederived data only when Chart is not sampling (during sampling, you
see any recorded data). Choosing the Differential… command from a
Channel Function pop-up menu displays the Differential dialog box forthat channel.
As with most channel calculations, you specify a source channel in the
Source channel pop-up menu.
The slider bars for the Smoothing and Multiplier controls can be used to
set values in the normal way, by dragging the sliding handle, or
clicking the slider bar area. The value is displayed below the slider bar.

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Figure 6–36
The Differential dialogbox.

By default, the Smoothing and Multiplier controls are set to No
Smoothing and ×1 respectively.
The Smoothing control lets you set the amount of smoothing used in the
differentiation, either none, or from 2 to 50 samples. The differential atany sample point is effectively the average of the slope of two lines.
One is from the sample point to a point n samples before it, and one isfrom the sample point to a point n samples after it, where n is thenumber of samples set using the Smoothing control.
The Multiplier control lets you amplify the differential waveform up to
1000 times. This is used to enlarge the differential waveform to make iteasier to deal with, since it can end up quite small if the signal changes
slowly.

Integral▼ Refer
Computed Input, p. 153

The Integral calculation provides the ability to calculate time-integrals
both online and offline. It is more versatile than the Computed Input
Integral functions, in that the integral can optionally be reset to zero by‘events’ (threshold crossings of a signal in any Chart channel).
Choosing the Integral… command from a Channel Function pop-up
menu opens the Integral dialog box for that channel, in which you
choose the source channel, the type of integral, the resetting mode andthe scale with which the integral is displayed.

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Figure 6–37
The Integral dialog box.

Auto puts ‘.s’ (forseconds) after existing
unit. Fixed lets you define
the unit.

Integral Type▼ Refer
Computations with
Computed Input
Functions and Channel
Calculations, p. 261

There are four types of integral that you can select from the Integral
type pop-up menu. They are similar to the computed input integrals, but
may give slightly different results, owing to the fact that computed input
functions always have a precision based on a sampling rate of 2000
Hz or higher, regardless of the sampling rate set in Chart.
∫ (Integral) calculates ∑y ∆t, where ∆t is the interval between samples. ∫Absolute Value calculates ∑|y| ∆t. ∫ Positive Only calculates ∑y+ ∆t,
where y+ = y if y > 0 and is zero otherwise. ∫ Negative Only calculates∑y– ∆t, where y– = y if y < 0 but is zero otherwise.

Resetting Mode
Every integral is set to zero at the start of a data block. The nature ofmost data integrals is to increase (or decrease) continuously. It is,therefore, usually necessary to introduce a resetting mechanism to keep
the integrated signal within bounds. Resetting modes are:

Chapter 6 — Data Analysis•

No Reset. The integral is not reset.

•

Timed Reset. Reset to zero occurs regularly at an interval entered ina text box.

185

Figure 6–38
The More Integral
Options dialog box.

•

Reset Each Cycle. The integral is reset each time the source signal
passes through zero to a positive value.

•

Time Constant Decay. The integral is not reset sharply, but tends todecline towards zero with a time constant as set in the text box.
With no input to the integral, its value decays to about 37% (1/e)
in each time constant. This is like a ‘leaky’ analog integrator.

•

Reset By Event is a generalization of Reset Each Cycle. The resetting
event can be on any channel or threshold level on a rising or falling
signal. You can also set a Skip time that locks out the event
detection for a specified time after an event occurs. The Skip time isuseful for preventing premature resetting by certain multi-peaked
repetitive waveforms. To set these options, click the More Options…
button in the Integral dialog box, which displays the More Integral
Options dialog box (Figure 6–38).

Integral displayed
as sawtooth
Integral displayed as
stepped waveform
Set whether resetting is
triggered by a rising or afalling signal
Set threshold level
for reset event
Further reset events
ignored during thistime

Select to calculate
integral overdefined time limits
Channel in which
reset event islooked for. Datachannel means thechannel chosen as
the source for the
integral

Other Integral Options
The More Integral Options dialog box (Figure 6–38) provides controls
for two further options, in addition to controls for resetting by event.
For integrals that have a timed reset, or are reset by cycle or event, you
can display the calculated integral as continuously increasing during
each cycle (giving a sawtooth-like appearance), or you can display it
as showing the value reached during the previous cycle, until the
integral is reset (giving a stepped appearance).
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Selecting the Partial Integral checkbox means that integrals arecalculated as definite integrals over the chosen limits. Before the firstlimit, the integral is zero. After the second limit, the integral holds its
value constant. This mode is most likely to be useful in a recording withmultiple data blocks.

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188

Chart SoftwareC H A P T E R

S E V E N

7 Customizing&
Automating Chart

Chart can be extensively customized and automated, to increase its
convenience and ease of use. It can be simplified or modified bylocking, hiding, or altering controls, menus, and menu commands.
Macros can be created to speed up and automate tasks, and added tomenus and the Tool bar; and new menus can be created. A timeschedule can be defined to control recording, voltage output, and soon. External devices can be controlled, and comments inserted
automatically in response to external events. Chart extensions (softwareplug-ins) are available to add extra features to Chart.

This chapter looks in detail at Chart preferences, customizing options,and recording automation and control functions.

Chart Software

189

Preferences▼ Refer
e-corder Startup, p. 229

The various options in the display settings and recording controls allow
basic customizing of Chart. You can also choose to lock, hide, or alter
controls, menus, and menu commands (and their keyboard equivalents).
This can be particularly useful in simplifying Chart for teaching
purposes. The commands in the Preferences submenu of the Edit menu
let you manage aspects of Chart behavior and display (Chart ande-corder startup, the external trigger, the Tool bar, cursors, menus,
controls, Chart extensions, memory allocation and data buffering).

External Trigger
On selecting Chart > Preferences > External Trigger…, the External
Trigger Options dialog box appears which lets you choose, whether a
TTL voltage level or a contact closure event will trigger recording.
Off

Figure 7–1
The External Trigger
Options dialog box.

On
External trigger
state indicator

The Current State indicator shows if the external trigger (Ex) is off (gray)or on (yellow), so that you can apply voltage levels or a contact closure
and observe the effects. The state indicator replicates the behavior of
the Trigger light on the front of the e-corder, and is useful if the e-corder
hardware can’t be clearly seen.

Tool BarOn selecting Chart > Preferences > Tool Bar…, the Tool Bar Settings
dialog box appears. It lets you choose whether the Tool bar is shown,and which buttons appear in it and how they are arranged. Initially, theVisible scrolling list displays all the standard buttons that appear, andthe Hidden scrolling list displays, for all available macros, the name of
the menu that the macro is in, a colon, and the name of the macro.

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Drag to place aseparator in the
Visible list

Figure 7–2
The Tool Bar Settings
dialog box.

Assign aFunction-key
equivalent fromthe pop-up
menu
Choose abutton icon fromthe Icon list

Names that are too wide are truncated: an ellipsis (…) replaces extra
characters. Once things are arranged, click the OK button to apply thesettings or the Cancel button to close the dialog box without making
changes.
Turning off the Show Tool Bar checkbox hides the Tool bar. This isuseful if you don’t have much room on your screen or don’t much carefor Tool bars. (The Tool bar can be moved by Shift-dragging it if you
just want it elsewhere.)
The order of items from top to bottom in the Visible scrolling list
indicates the order of buttons from left to right in the Tool bar. A
separator (dotted line) in the list adds a space between buttons, so that
buttons with similar functions can be logically grouped.
Items can be moved to alter the default arrangement. Just drag an itemby its title (to the left of the vertical bar) to move it. The pointer changes
to an arrow-headed cross, and as you drag, a gray outline indicateswhere the item will go. When items are moved to, or about in, theVisible scrolling list, a horizontal line and left-pointing triangle indicate
the insertion point. Items moved to the Hidden scrolling list are justadded to the bottom; separators are discarded, since new ones canalways be added to the Visible list by dragging from the (left side ofthe) permanent one at the top of the Hidden list.
The icon for a standard item cannot be changed, but a macro item canbe assigned an icon by dragging one from the Icon scrolling list. The
pointer changes to an arrow-headed cross, and a gray outline shows
Chapter 7 — Customizing & Automating Chart

191

where the icon will go. The item highlights if the pointer is over it: theicon appears at its left when dropped, replacing any icon alreadythere, and will appear on its button if it is in the Visible scrolling list.
Use an item’s pop-up menu, to the right of the vertical bar, to assign
one of the 15 Function keys (F1 to F15) to a button, for use with anextended keyboard (the default is none, a blank). Pressing the assigned
key activates the macro, even if the button or Tool Bar is hidden. Notethat Function keys assigned to a button on the Tool Bar override thosesame keys assigned for automatic comments.

CursorChoose Chart > Preferences > Cursor… to open the Waveform Cursor
dialog box (Figure 7–3). Click one of the radio buttons to choose a
Waveform Cursor shape that is easy to see when tracking the
waveform. The line cursor is a vertical line that crosses all channels,
with short bars where the waveforms are intersected. It is useful with alarge screen or noisy waveforms, when the other Waveform Cursors
might be harder to see. Click the OK button to apply your choice.
Figure 7–3
The Waveform Cursor
dialog box.

Menus
The six Chart menus (File, Edit, Setup, Commands, Macro, Window)
and their commands can be modified from the default settings by using
the Menus dialog box. Choose Chart > Preferences > Menus… to open
this dialog box. You can hide or lock any menu or menu command tocreate a very simple Chart setup, if you want to limit the actions thatcan be performed. This is particularly useful for teaching in a laboratoryenvironment, where you might want students to be able to use somefeatures of Chart, but not to edit, delete, or change the data in files.

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Chart Software

Figure 7–4
The Menus dialog box.
Click on a
keyboard shortcut
to change it

Deselect checkboxes to hidemenus and menu items

Click on a padlock todisable a menu item

The dialog box will initially display just the menu names in the left-handpane: to see the items for a particular menu, select the menu name.
By default, menu titles and all items within the menus will have selected
checkboxes to their left, and all menu commands will have open
padlocks beside them as well, indicating that everything is visible andunlocked. Items in submenus cannot be edited, but the submenus
themselves can be hidden. Locking or hiding a menu command will
have no effect on the equivalent Tool bar button.
Deselecting the checkbox beside a menu title will hide the menu: it will
not appear in the menu bar when you return to the Chart window, andany keyboard shortcuts in it will not work. Deselecting the checkbox
beside a menu command or a dividing line hides it: it will not appear
in the menu, and neither will any keyboard shortcut work. Selecting acheckbox again will show the previously hidden item beside it.
Clicking an open padlock (with a U for unlocked on it) changes it to aclosed padlock (with an L for locked on it), and locks the menu
command beside it. The command still appears in the menu, but if it ischosen or the keyboard shortcut typed, an alert notifies the user that it islocked and cannot be used. Clicking a closed padlock changes it to an
open one, and unlocks the previously locked menu command beside it.

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Keyboard Shortcuts
Keyboard shortcuts for menu commands can be added or changed.
Click the shortcut text next to a menu item to select it: the text highlights
and the letter key appears selected. You can either change it, or delete
it so that no keyboard shortcut is available. To assign a keyboard
shortcut, type a single lower-case letter or number in the text entry box(letters are automatically capitalized; invalid characters will berejected).

▼ Refer
Shortcuts and Tips,
p. 237

If you choose a character already in use, an alert box will warn you of
the fact and tell you where it is assigned. If you choose the character
anyway, your choice overrides the previous assignment, and the
keyboard shortcut (Command-S, or whatever) will only work for (andappear beside) the menu command that you have chosen.

Controls
On selecting Chart > Preferences > Controls…, the Controls dialog box
appears. By default, all the checkboxes are highlighted, and theirfunctions active. Click the checkbox or the function beside it to toggle
the function off or on. The dialog box allows you to remove Chart
functions that could be confusing or are unnecessary for a student or
new user, who might easily feel lost and bewildered by choice. Click
OK to apply your changes.
Allow Printing of Whole File. Turning this checkbox off disables the Print
All… command in the File menu — other printing commands such as
Print Selection… are still available, but the whole file cannot easily be

Figure 7–5
The Controls dialog box.

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printed. This is useful in student labs, where usually only a small portionof a file would need printing.
Record/Monitor Control. When this checkbox is turned off, theRecord/Monitor button is hidden. This can help prevent new users
losing data by accidentally clicking the button and switching fromrecording to monitoring. Even if the button was set to monitor before thecontrol was hidden, Chart will only record, not monitor.
Scroll/Review Control. When this checkbox is turned off, theScroll/Review button is hidden. This can help prevent new users
becoming confused, should they accidentally set the review option, andChart’s data stops scrolling, and so on.
Computed Inputs. When this checkbox is turned off, the Computed
Inputs… menu command disappears from the Channel Function pop-up
menu, so that the Computed Input dialog box is no longer accessible
from there.
Channel Calculations. When this checkbox is turned off, the options in
the lower half of a Channel Function pop-up menu that perform channel
calculations on data are removed (including those added by Chart
extensions). This helps to prevent new users confusing recorded data
(raw or computed) with calculated data.
Full Trigger Window. When this checkbox is turned off, the Start andStop Cycling controls do not appear in the Trigger window.
The Computed Inputs and Channel Calculations controls don’t stop
access to the functions through the columns in the Channel Settings
dialog box, so to stop access you should hide the Channel Settings…
menu command as well.
Note that the settings for Computed Inputs, Channel Calculations, andthe Trigger Window (such as pre-triggering or the number of blocks
after which to stop cycling) remain in effect, so make sure they are set
to what you want before you hide them.

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License Manager
The Chart License Manager allows you to view, add and delete licensecodes for Chart. Choose Chart > Preferences > License Manager… toopen the License Manager dialog box (Figure 7–6).
Existing license codes and their descriptions are shown in the lower halfof the dialog box. Note that the last four characters of the license code
are shown as ‘xxxx’ — you will have been provided with the full licensecode including the last four characters when you purchased thesoftware. To add a license code, enter it into the License Code text box
and click Add. The new code will appear in the dialog box.
To delete a license code, select it and then click Delete. You will be
asked to confirm the deletion. If you delete your Chart license code, thenext time you try and run Chart, you will be prompted to enter a valid
license code. Chart will not run until you have done this. If you delete
all the license codes shown in the License Manager dialog box, you
can edit the entries in the Name and Organization text boxes.

Figure 7–6
The License Manager
dialog box.

Chart Extensions
Chart extensions are additions to the Chart program that add extra
functionality, such as file translation capability, data analysis. For
example, the Export MATLAB extension allows you to save Chart files ina format readable by the data analysis application MATLAB. Extensions
are separate files that may be downloaded free from the eDAQ web

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Figure 7–7
The Extensions Manager
dialog box, showing
some extensions.

Click on a(it toggles to a

) to deactivate an extension

site (www.eDAQ.com), along with documentation that describes how to
use them.
When Chart is installed, the ‘Chart 5’ folder created in your
Applications folder includes an Extensions folder. This folder should not
be renamed or moved, or no Chart extensions will load. To install an
extension, quit Chart and place the extension file in this folder, or run
the installer if one was provided. Extensions in the Extensions folder will
be loaded when Chart starts up.
The Extensions Manager dialog box lists the Chart extensions within thefolder, explains what they do, and lets you choose which of them will
be loaded when Chart starts up. Choose Chart > Preferences >Extensions… to open the dialog box. Chart extensions in the Extensions
folder are shown in the scrolling list at the left. Click one to select it: itsversion number and a description appears to the right.
It is unlikely that you will want to use all the Chart extensions. Tochange the ones used, click the ticks or crosses in the list. Clicking atick will toggle it to a cross, and vice versa. Those Chart extensions
marked with a tick will be loaded when Chart starts up; changes takeeffect when Chart restarts. You can decide which Chart extensions
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should be loaded during startup, as well. Hold down the space bar as
Chart starts up to open the dialog box, and click the tick or crossbeside each Chart extension to change its status.

Memory Cache▼ Refer
Recording Length, p. 32

If your computer is taking a lot of time to perform actions on large files(such as redrawing windows), it may help to change the size of thememory cache. Choose Chart > Preferences > Memory Cache… toopen the Memory Cache dialog box (Figure 7–8). Then select the
Manual option and adjust the size of the memory cache by adjusting
the position of the slider bar (depending on the system and resources
being used, performance may be improved by either decreasing or
increasing the size of the cache, so you may need to experiment withboth).

Figure 7–8
The Memory Cache
dialog box.

Data Buffering▼ Refer
Recording Length, p. 32

198

Data buffering lets you choose where the data you record will be
stored, memory or disk. Files are stored on the system disk (the current
startup disk) by default. Recording data to RAM (physical memory) may
be faster than recording to disk when using a slower computer.
However, the benefits will be limited by the amount of RAM you have;
if you need more space for the file you are recording than there is
RAM, Chart will start using virtual memory, which accesses the harddisk anyway. Most systems have more disk space than RAM, and data
buffered to disk by Chart can survive a power failure or system crash,so recording to disk is a better choice unless the slowness of yourcomputer forces you to record to RAM. Data buffering settings can be
Chart Software

Click the appropriate
button to record tomemory or disk

Figure 7–9
Data Buffering dialog
box.

Select a different location
for disk buffering
Use the default disk
buffering location

changed only when Chart has open either no file or a new file with nodata. Close any open Chart file containing data and choose Chart >Preferences > Data Buffering… to choose where data will be buffered.
The dialog box in Figure 7–9 appears.
If recording to disk, you can select a different disk buffering location(on a different disk, perhaps) by clicking the Choose button. The
amount of free space on the disk containing the chosen folder isdisplayed. Note that this is a temporary location, different from thelocation you choose in the Save dialog box when you save a file. Data
can be recorded to an internal or external hard disk, removable media
such as magneto-optical disks or removable hard disks. Hard disks are
generally faster than the other options. Care should be taken thatremovable media are not removed in the middle of recording! When
Chart comes to write to a removed disk, it will open the standard
system dialog box asking you to insert the missing disk, and will cease
recording until the disk is inserted.
If Chart is set up to record to disk, it creates a buffer file as soon as it
starts up. This temporary file is called ‘…Chart Buffer File…’ in the
Finder and has a different icon from normal files. Blocks of data are
written to the file at set intervals when sampling. As a general rule, a
new block is written to disk every 16 000 samples or every two
minutes, whichever comes first. Once recording has finished, you stillmust save the file using the standard Save command. Quitting Chart or
opening a new file will prompt you to save the file first: if you abandon
it at this stage, the data will be lost. When a file is saved, all thebuffered data are written to it, and the buffer file is emptied, ready for

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the next bout of recording. When you quit Chart normally, the buffer
file is erased.
In the case of a problem that terminates sampling, Chart only loses a
maximum of the last block of data recorded, that is, 16 000 samples or
the last two minutes of recording. The rest is stored in the buffer file. The
next time Chart runs, it searches for a buffer file. If it finds one, an alert
box indicates that the file being recorded prior to the problem needs
recovery (since it will not have been saved properly). In most cases,
most of the buffered data should be recoverable. If you choose todelete the file, the data will be lost.

Startup
Settings are of two sorts: those that affect recording, such as sampling
rate, channel ranges, triggering, and stimulation functions; and thosethat affect the way the data looks, such as the menu configuration,
window size, channel areas, and display settings. To save or clear
customized settings, choose Chart > Preferences > Startup… to open
the Startup Settings dialog box.
Click the Save button to save all current settings in a preferences file
(Chart StartUp) in the user’s Preferences folder, so that they are usedeach time Chart starts up. Click the Clear button to clear any settingscurrently stored in the Chart StartUp file: when Chart next starts up, it
uses its default settings, taking the whole screen for its display, withvisible channels having a 10 V range, and so on. (Settings in use
remain until you quit and restart Chart.) To bypass the current startup
settings and use the default settings for a single session, hold down theCommand key as Chart starts up: release the key when the alert box
appears, and click the Yes button.

Figure 7–10
The Startup Settings
dialog box.

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Special Access
Because it is possible to change menu preferences so that vital menu
commands are locked or menus themselves hidden, it is necessary tohave a back door in. Access to dialog boxes often needed, but madeunavailable in order to safeguard files, is possible through the Special
Access dialog box, which appears on typing Command-\ (thebackslash character). If your keyboard does not have a \ character,type Control-Command-1 instead.
Clicking the Menu Editor… button opens the Menus dialog box, letting
you show hidden menus, unlock menu commands, and otherwise altersettings. This is obviously useful if by locking or hiding things you haveremoved access to that dialog box.
Clicking the Tool Bar… button opens the Tool Bar Settings dialog box,
letting you choose whether the Tool bar appears, and which buttons
appear in it and how they are arranged. This is useful, say, to change
keyboard shortcuts, which still apply if the Tool bar is hidden.
Clicking the Save As… button opens the Save As dialog box, whichallows you the complete range of options in saving a Chart file. It isuseful where you have disabled the ability to save a file, andparticularly to save the file as a Settings file with the hidden or locked
menu items remaining as specified when the file was saved.
Clicking the Controls… button opens the Controls dialog box, whichlets you remove Chart functions that could be confusing or are
unnecessary for a student or new user. This is useful to reinstatefunctions when they are required.

Figure 7–11
The Special Accessdialog box.

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Clicking the Startup… button opens the Startup Settings dialog box,
letting you save the current settings in the file (including menu layouts
and so on) as those Chart will use when it starts up. This is useful when
you use Chart for routine work requiring the same settings day afterday. It also means that quitting and restarting Chart will not face theuser with a Chart file that could have quite different settings, and noneof the safeguards you may have set up.

MacrosMacros are used to group sets of commands together conveniently,
letting you speed up repetitive and tedious tasks, such as changing thesettings for various parts of an experiment. They can help to automate
recording and analysis. They record the results of your actions step bystep, then reproduce them when played back. If you find yourself
regularly doing the same series of tasks in Chart, whether simple orcomplex, macros can ease things considerably. Macros can record
almost any Chart operation: setting dialog box and window controls;changing the display format; sampling; copying waveform data to the
Data Pad; saving data as a new file; printing the Zoom window displayof selected data; and so on. There are some differences between
recorded and real operations, but in general, dialog boxes will guide
you through your options.
Note that macros record the results of your actions, not individual
keystrokes and mouse clicks, and record the simplest possible
interpretation of those actions. Even if you spend some time fiddlingwith control settings during the recording of a macro, only the final
settings you obtain will be used. Macros cannot be edited, and may be
incompatible between versions of Chart.
You should keep a written record of the steps involved in your macros,and their purpose: it is easy to forget which macro does what when you
haven’t used them for a few weeks. Noting the steps down before
actually recording will help when constructing complex macros, since it
can prove easy to miss out a step or end a repeated sequence in thewrong place, with detrimental effects.
When a file is saved, all currently available macros are saved with it,
becoming part of the file. When you open a Chart data or settings file,
any macros in that file are loaded into memory. In the Open dialog box
there is a Discard Existing Macros checkbox. If this is on, macros
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Chart Softwarecurrently in memory are discarded when the file is opened, and any
macros in the opened file replace the previous set. If the checkbox isoff, macros accumulate in memory as you open files until you quit andrestart Chart, or delete the macros.

Recording a Macro
To record a macro, choose Macro > Start Recording or type CommandR (the menu command then changes to Stop Recording…). When amacro is being recorded, for the most part Chart remembers rather than
executes operations, but opening files, changing channel ranges, or
turning channels off, for example, are done as you record.
During the process, a progress indicator is shown in the text box of theTool bar, to remind you that your actions are being recorded, notnecessarily effected. Perform all actions to be recorded, then choose
Macro > Stop Recording… or type Command-R again to finish. The
New Macro dialog box appears (Figure 7–12).
The Menu pop-up menu lets you choose the menu in which your macro
will appear from a list of existing menus. By default, the macro will be
added as a new menu command to the Macro menu. You can create a
new menu by entering its title (up to 10 characters) in the Menu text
entry box: it will be added to the right of the Macro menu in the menubar. The name of the macro (up to 20 characters) should be entered in
the Item text entry box. Each name must be unique in its menu. To
create a menu divider, so that similar macros can be logically grouped,record a simple macro (playing a sound, say), and start the macroname with two hyphens (--). It will appear only as a divider in the menu,
and cannot be chosen (it is accessible through the Tool bar, though).

Figure 7–12
The New Macro dialog
box.

Type here to create a new menu
Click here to choose a menu towhich to add the macro
Type a name for the macro here
Assign a keyboard shortcut here

Chapter 7 — Customizing & Automating Chart203

▼ Refer
Shortcuts and Tips,
p. 237

An optional keyboard shortcut can be assigned to the macro as well:
type a single lower-case letter or number in the text entry box (letters
are automatically capitalized; invalid characters will be rejected). An
alert box will warn you if you choose a character already in use, andtell you where it is assigned. If you proceed anyway, your choice
overrides the previous assignment, and the keyboard shortcut will only
work for (and appear beside) the menu command just created.
The Size indicator tells you the number of steps recorded (useful if you
can’t remember which step you are up to in the middle of a complex
macro), and the memory used by the macro (which depends on theprocedure). Click the Discard button to discard the macro you have justrecorded. Click the Cancel button to leave the dialog box and record
more steps in the macro. Click the Add button to add the macro to thebottom of the selected menu; the button is only active and undimmed
when the macro is named and a menu is chosen.
Until you save the file, new macros exist only in memory and are notpermanently stored. If you open another file (without discarding
currently available macros) and save that file, the macros will become
part of the new file. When you quit Chart, you will not be asked to savechanges if the changes are only concerned with macros, so it is a goodidea to save the file each time you create a macro.

Playing a Macro
Once assigned a name and location, a macro acts much as if it were amenu command. To use one, select it from its menu or type its keyboard
shortcut (or click its button in the Tool bar). While a macro plays, thetitle of the menu in which it resides is highlighted, the message ‘Playing
Macro…’ is displayed in the text box of the Tool bar, and no otherfunctions can be performed within Chart. If you switch to anotherapplication and leave Chart in the background, the macro stops
playing at its current step. To stop a macro playing at any time, typeCommand-period (.): the macro stops at its current step.

Deleting a Macro
To delete existing macros, choose Macro > Delete Macro… to open the
Delete Macro dialog box. A scrolling list displays the name of the menu
that the macro is in, a colon, and the name of the macro, for all

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Figure 7–13
The Delete Macro dialog
box.

available macros. To delete a macro, select it and click the Delete
button. To choose multiple macros for deletion, Shift-click or Shift-dragto select contiguous macros, or Command-click to select or deselectmacros individually. Once the Delete button is clicked, the dialog box
closes and the macro or macros will be gone. As a shortcut, doubleclick a macro to delete it and close the dialog box in one step.
As was mentioned, macros are part of a particular file, and when a fileis saved, all currently available macros are saved with it. When you
delete a macro, you delete it from memory. If it has been assigned abutton in the Tool bar, the button disappears. If the macro is part of thecurrent file, it is permanently deleted from that file only when the file issaved (although it will not be available while the file remains open).
Copies of the macro attached to other files are not deleted.

Options When Recording Macros
Operations involving files and dialog boxes can be made to behave
differently when playing macros, depending on whether you want to do
the same thing all the time, allow user modification, and so on.

Changing Dialog Box Settings
Macros can be used to change dialog box settings to values specified
when you record, or to open a dialog box for the user to change
settings when the macro is played.
If you want a macro that changes the settings in a dialog box, thenselect the dialog box as you would normally while recording the macro.
Change the settings, and then click OK in the dialog box. (If you click
Cancel, changes made in the dialog box are ignored.) When playing
the macro, the settings are changed without displaying the dialog box.

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When changing control values in dialog boxes, absolute values arerecorded, not relative changes. For example, if you move a slider bar
that increases voltage from 2 V to 3 V, the new voltage (3 V) is
recorded, not the change in voltage (+1 V) or the percentage change involtage (+50%).
If you want a macro that lets the user change dialog box settings whenthe macro is played, then while recording the macro, hold down the
Option key when selecting the command that shows the dialog box,
then click the OK button. Do not make any setting changes. When themacro is played back, the dialog box is displayed so that its settings
can be changed by the user. At that stage, clicking the OK or Cancel
buttons in the dialog box lets the macro continue, with the user-definedsettings or the original settings respectively.

Starting Sampling▼ Refer
Wait While Sampling,p. 221

Macros can be used to control when sampling starts and stops. Should
you click the Start button when recording a macro, the Macro Sampling
dialog box will appear. In general, you would probably want to retain
the default setting in the upper part of the dialog box (that is, stop themacro while sampling), but in some cases you might want to perform
steps as sampling proceeds (adjusting some settings, for example).
Another macro command, Wait While Sampling, lets you suspend
sampling after a particular step, if you choose this option. The lower
part of the dialog box allows you to specify when sampling stops. This
could be useful to override, for a certain portion of an experiment, a
fixed duration set in the Trigger window.

Figure 7–14
The Macro Sampling
dialog box.

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Opening and Appending Files
A macro can be used to open or append the same file each time it isplayed, or to allow the user to choose a file. To open or append aparticular file with a macro, choose File > Open… or File > Append…
while recording a macro: in each case the Open File for Macro dialog
box is displayed. To append rather than open a file, turn on the
Append checkbox.
To let the user choose which file is to be opened or appended when themacro is played, press the Option key when selecting the command
while recording the macro. An alert box reminds you that you are
giving the user a choice. The Open dialog box will be displayed whenthe macro is played.
When opening the same file each time, if the file has been moved (ordeleted) since the macro was recorded, then Chart searches in the mostrecently used folder and in the same folder as Chart. If the file is inneither place, an alert box lets you know that Chart cannot find the file,and the Open dialog box is displayed to allow you to find it yourself. If
you choose a different file at this stage, that one will be opened
instead; if you click the Cancel button, the macro will stop.

Figure 7–15
The Open File for Macrodialog box.

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Saving Files
When playing a macro, you can save data in a file or in a series offiles. Choosing the plain Save command will save a current named file.
You might want to do this at specified intervals to minimize data loss incase of possible power loss. To let the user choose where and underwhat name the file is to be saved when the macro is played, press the
Option key when selecting the command while recording the macro.
An alert box reminds you that you are giving the user a choice, and theSave As dialog box will be displayed when the macro is played.
Data are not recorded during the time it takes to save a file to disk, solarge files might take a while to save. To minimize data loss during
automated recording, you can instead save a series of short files, andalso specify where and in what form you want the data to be saved, bychoosing File > Save As… or File > Save Selection… when recording
the macro. The Save File for Macro dialog box appears. The formats
are data file, settings file, and so on, as usual.
The three ‘Append filename with’ checkboxes let you specify unique filenames. If none are turned on, then each time you play the macro, theFigure 7–16
The Save File for Macrodialog box.

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Chart Softwarefile will be overwritten, just as it is when saved normally. If the Unique
number checkbox is selected, a different number is added to the end of
the given file name each time the file is saved during the playing of themacro. Numbers are added in numerical sequence starting with ‘1’. For
example, if the file name is CoolData, then the next files generated will
be CoolData(001) and CoolData(002). If the macro is played again,
numbering will follow on from the last such numbered file to give
CoolData(003) and so on. Selecting the Time checkbox appends thecurrent time to the file name. Selecting the Date checkbox appends thecurrent date to the file name. The two may be combined. Thesecheckboxes are dimmed and unavailable if the Unique number
checkbox is selected.

Macros That Call Other Macros
Once a macro has been created, it can be used by other macros (when
it is loaded in memory) as a step in the recording of the new macro.
This enables modular construction of complex procedures. Macros canonly be nested up to ten deep, however. An alert box will appear
during the playing of your macros if the combination becomes toorecursive, and the macro sequence will stop at that stage. If a macro iscalled by other macros, Chart warns you if you attempt to delete it. If amacro is deleted without being replaced, then if it is called, an alert
box tells you that it cannot be found, and the calling macro stops.

Macro Commands
Control structures for macros are provided in the Macro Commands
submenu; the menu commands are only available while recording amacro. They let you provide user feedback using dialog boxes andsounds, set up repeat sequences, wait for a certain time, and so on.

Update Screen
Normally, when a macro is played, the screen is updated after eachmacro step (a tick beside the Update Screen menu command indicatesthat it is active). Choosing the command from the menu as the first stepin a macro causes the macro to play without redrawing the screen eachtime the data display is altered in some way (the tick disappears).
Update Screen can be turned off or on at any stage of a macro. The

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settings toggle. If Update Screen is off, the screen will be redrawn only
when the macro is finished, or it is turned on again.
This may considerably speed up some macros, for example, those
involving multiple changes to view and display settings, or repetitive
selection and transfer of data to the Data Pad: in this case, the data on
screen will still be seen to be selected, but data off screen will not be
scrolled through before selection, as would occur if Update Screen
were on (it was ticked in the menu). Since you cannot edit macros, you
cannot change the Update Screen settings once the macro is finalized.
You can, however, record another macro that consists of two steps:
turning update screen off or on, then calling the original macro.

Wait…
Choosing the Wait… macro command opens the Wait dialog box. A
pop-up menu lets you choose from Wait For, Wait Until, and Wait Until
the Next, to wait for a set length of time (say, 55 seconds), wait until acertain time (say, 11:20 a.m.), or wait until the next time division (say,at the next hour) before the macro continues.

Figure 7–17
The Macro Wait dialog
box, showing the three
options selected.

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The checkbox lets you choose whether a dialog box with a progress
bar appears during the wait (generally a good idea). The dialog box
gives a visual indication of wait progress, and provides the options ofproceeding immediately to the next step of the macro by clicking theSkip the Wait button, or aborting the macro by clicking the Stop Macrobutton (equivalent to typing Command-period).
This feature is useful if you want to perform some steps of anexperiment at certain intervals, or to record multiple sampling
sequences with a specific interval between them.

Figure 7–18
The Macro Wait dialog
box during the playing of
the Wait step of amacro.

Play Sound…
Choosing the Play Sound… macro command opens the Macro PlaySound dialog box, which allows you to choose from the range ofsounds in your computer’s system to set audible alerts in macros. Clickthe name of a sound in the scrolling list to select it. If you wish to hear
the selected sound, click the Play button. To have it actually played in
the macro, click the OK button (which closes this dialog box). To
choose more than one sound option, Shift-click or Shift-drag to selectcontiguous sounds in the list, or Command-click to select or deselectmultiple sounds individually. Sounds appear in the list in the order they
were installed in the system, and are played back in that order. To savetime in creating multiple sounds, you can create a library of soundcombination macros, and simply incorporate one or more of them inthe macro that needs them.
You might wish to have three beeps signal when the e-corder starts
recording data, or a bell and a whistle when a trigger point has beenreached. You can even record short verbal cues, if your computer has a
microphone input, using the Sound System Preferences, and use thesein your macros.

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Figure 7–19
The Macro Play Sounddialog box.

If a macro attempts to play a sound not in the system (created on acomputer with a different setup, or since removed from the system), thenan ordinary system beep will be substituted for the sound originallyspecified.

Message…
If you select the Message… macro command, the Macro Message
dialog box appears. This allows you to cause alert boxes requiring user
response to appear at certain stages within the macro.
You can type in the message of your choice (up to 255 characters). The
dialog box produced will have an OK button, and if the checkbox at
the top is on, a ‘Cancel’ button as well (for exiting the macro). There
are four choices of icon: the default shape is highlighted. Click one of
the icon buttons to choose it. You can use the icons to indicate theurgency of an important message, and the Chart icon for generalmessages that indicate Chart’s state. Click the OK button when you

Figure 7–20
The Macro Message
dialog box.

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Chart Softwarehave chosen an icon and typed in the message. You could use
messages to remind you what the macro does.
It may help to notify a user that something is up if you precede an alert
box with an audible signal (using the Play Sound… macro command),since he or she may not be looking at the screen when an alert box
appears.

Speak Message…
If you choose the Speak Message… macro command, the Speak
Message dialog box appears. You can use it to give audible messages
in macros, if the computer playing the macro has speech available. You
can type in the message of your choice (up to 255 characters). If the
Use System Volume checkbox is on (it is by default), the volume atwhich the message is spoken is the system volume set in the Sound
System Preferences. If this checkbox is off, the volume can be set withthe slider bar.
Three radio buttons give a choice of actions when the macro step isreached, depending on whether you want to display an alert box, justas if the Macro message dialog box were used, and whether thecomputer on which the macro plays has speech enabled. If an alert box
appears, it will stop the macro until its OK button is clicked. If not, themacro carries on playing after this step.

Figure 7–21
The Speak Message
dialog box.

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If the Never radio button is on, then the message will be spoken if
speech is enabled, otherwise a standard system beep is used instead.
In either case no alert appears. If the Only if Speech is not Available
radio button is on, then the message is spoken if speech is enabled,
otherwise the alert appears. If the Always radio button is on, then an
alert box appears whether or not speech is enabled.

AppleScript…
This macro command allows you to insert an AppleScript as a macro
step. AppleScript is a scripting language for automating tasks, andcontrolling applications and their interactions through Apple events. It
should be installed on your computer. On selecting the AppleScript…
macro command, the AppleScript from Macro dialog box appears. You
can enter a script of 32 000 characters in the scrolling field. The dialog
box is a movable modal one, which means you can switch out ofChart, to get tested scripts from the Script Editor, say, and paste themin. You will lose text styles from a formatted script if you do this: scripts
are just left as unformatted text in the dialog box, even when compiled
there.
Click the Check Syntax button to check and compile the script — youare told if the script will not run. The AppleScript is checked andcompiled once you click the OK button, if you have not checked it
already. It will look for named applications at that stage. Click the Test
button to actually run the script (so that you can see how it works, while
you are recording the macro).

Figure 7–22
The AppleScript fromMacro dialog box.

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Once you click the OK button, the AppleScript is stored as one step of
the macro. It thus can’t be edited, but it is recommended that only
simple scripts will be used from within Chart: complex scripts that might
require adjustment are better left residing in the Finder, and then calledusing a simple AppleScript macro step within Chart.
For example, you could transfer data to an Apple event aware
spreadsheet as you worked through a Chart file, by running a macro to
cut a line from the Data Pad, and using an AppleScript step to switch tothe spreadsheet, paste the data into the next row, and switch back toChart.
Chart is Apple event aware, but not Apple event recordable, and has
no dictionary. It supports the required suite, and one more command.
The macro to be played by the ‘do script’ Apple event is identified by
the name of the menu that the macro is in, a colon, and the name of themacro (just as it is shown in the Delete Macro dialog box). You don’t
need to tell Chart to activate: it is automatically brought to the front
when this event occurs. If an AppleScript macro step both switches outof Chart to some other program and then switches back in, the macro
carries on and completes any remaining steps. If the AppleScript
switches out of Chart, but does not switch in again, then the macrofinishes at that step, and any remaining steps are ignored.
Learning AppleScript is left up to you — it is not trivial, but is worth it if
you want to do a lot of automation. Check the Mac OS X help or theAppleScript web site (www.apple.com/applescript/) for documentationand example scripts.

Table 7–1
Apple events understoodby Chart (it can also
send other Apple events
to programs thatrecognize them).

CommandFunction

Exampleopen

Open the specified Chart document

open file "Test Results"

print

Print the specified Chart document

print file "Test Results"

quit

Quit Chart application

quit application "Chart
v5.0"

run

Launch Chart application

run application "Chart
v5.0"

do script

Play the specified Chart macro

do script "Macro:Beep"

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215

Repeat While in Block▼ Refer
Finding Data, p. 133

This macro command allows you to perform some operation while theselection or active point remains within a block of data. You should
specify an End Repeat command after the instructions you want
performed in the repeated sequence. For instance, you may want tofind all the peaks from the start to the end of a block of data, andrecord their heights in the Data Pad. You would make use of the Find…
command for this:
1. Choose Macro > Start Recording.
2. Choose Commands > Find…, and set up the Find and Selectdialog box: Go, Start of This Block, Set Active Point.
3. Choose Macro > Macro Commands > Repeat While in Block.
4. Choose Find… again, and set up the Find and Select dialog box
for the search: Find Data, Next, Local Maxima, Set Active Point.
5. Choose Commands > Add to Data Pad.
6. Choose Macro > Macro Commands > End Repeat.
7. Choose Macro > Stop Recording.
8. Name the Macro and assign a keystroke if you wish.

Repeat While in Selection
This macro command works similarly to the Repeat While in Blockcommand except that it allows you to perform some action from thestart to the end of a selection rather than from start to end of a block.

Repeat Select Every…
This macro command allows you to select sequential periods of data ina Chart file and to perform some operation on them. When you choose
the Repeat Select Every… macro command, a dialog box appears,
allowing you to set a selection period (with a minimum selection of two
data points) and choose whether the command applies to the whole
file, the currently selected block or to a current selection. You could, forexample, transfer data to the Data Pad for every ten-second period
within a given block.

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Chart Software

Figure 7–23
The Repeat Select Everydialog box.

If the Allow partial selections checkbox is selected, and the recording
period is not an exact multiple of the selected time period, the last
selection will be a shorter time making up the balance — for example,
if the file were 45 seconds long and the selection period 10 seconds,
the last selection would be the remaining five seconds. If the checkbox
is off, the last selection in a block will not be included in the case where
the length of the block is not an exact multiple of the selected time
period.
Figure 7–24 shows a macro selecting a period of data (0.1 seconds)
sequentially through a Chart file: each selection of data is dealt with
before moving on to the next one. When this macro command plays, itwill scroll through the Chart file and highlight each new selection,
which may take a while unless the Update Screen command is turnedoff.

Figure 7–24
The Repeat SelectEvery… macro commandin action.

Chapter 7 — Customizing & Automating Chart

Period of selection(0.1 seconds here)217

You cannot nest this command within itself, but you could nest it within
the Repeat Select Each Block command, say, if you wanted to copy themean of a channel for each ten-second period in a block to the Data
Pad, and write the data of each block to a new file. You should specify
an End Repeat command after the instructions you want performed in
the repeated sequence.

Repeat Select Each BlockThis macro command allows you to perform some operation on eachblock of data in turn in the Chart file. For instance, you may want to get
the mean of a channel for each block and copy the information to the
Data Pad. When this macro command plays, it will scroll through theChart file and highlight each new block, which may take a while: turnoff the Update Screen command to avoid the visual feedback. As withall Repeat macro commands, you should specify an End Repeat after
the instructions you want performed in the repeated sequence.

Begin Repeat
The Begin Repeat macro command is used to repeat steps in a macro.
You can repeat any group of commands up to 100 000 times. This
could be used, for example, to set up fast sampling at staggeredintervals overnight. You should specify an End Repeat command after
the instructions you want performed in the repeated sequence.

Figure 7–25
The Begin Repeat dialog
box.

End Repeat
Each and every Repeat macro command step you specify should be
paired with an End Repeat. If you do not specify enough End Repeat
steps, Chart adds them when you choose Stop Recording…, but if you
have a complex macro, the repeated sequences might not end up in the

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right places. Writing down the macro before recording it will help toavoid such problems.

Set Units Conversion…

▼ ReferUnits Conversion, p. 46

The Set Units Conversion… macro command lets you automate units
conversion. It may be more convenient to use this command in a macrorather than the proper Units Conversion dialog box. On choosing thecommand, the Set Units Conversion dialog box (Figure 7–26) appears.
Select the Point 1 or Point 2 radio button to select the first or second
pair of values. You can choose the recorded data of a particularchannel, or the mean, maximum, or minimum values from a selection ofrecorded data, using the Channel and Selection pop-up menus. The
converted value should be typed into the Value text entry box. Choose
or define units from the Units pop-up menu.

Figure 7–26
The Set Units Conversion
dialog box.

To get a macro that converts the units of a channel into a percentage ofthe maximum reading, say, you should perform the following steps:
1. Select data containing the greatest and smallest data points in thechannel you want to affect.
2. Choose Macro > Start Recording.

Chapter 7 — Customizing & Automating Chart219

3. Choose Macro > Macro Commands > Set Units Conversion… toopen the Set Units Conversion dialog box.
• Click the Point 1 radio button in the dialog box (if it is notalready selected).
• Click the Selection radio button.
• Choose Minimum from the pop-up menu beside it.
• Enter ‘0’ in the ‘Value’ box.
4. Click ‘OK’.
5. Choose Macro > Macro Commands > Set Units Conversion… toopen the Set Units Conversion dialog box again.
• Click the Point 2 radio button in the dialog box.
• Click the Selection radio button.
• Choose Max from the pop-up menu beside it.
• Enter ‘100’ in the ‘To Value’ box.
6. Define units of ‘%’ using the Units pop-up menu.
7. Click ‘OK’.
8. Choose Macro > Stop Recording.
9. Name the Macro (‘Percent’, or whatever) and assign a keystroke
if you wish.
On finishing recording, you can apply this macro to any channel as
required. Remember that it only applies to the current selection, so you
will have to select a range of data including the largest and smallest
points recorded to have the scale set correctly. To select an entire
channel, Command-drag to select a rectangle the full height of achannel at its start of the record, scroll to its end, and Shift-click toextend the selection — this ensures that all data points are included.
This feature can also be used for automatic calibration of transducers
during setup. To do this, set up a macro with prompting messages. You
must select the channel you are going to use, which means you musthave started recording — simply start and stop, then click the channel
to which the transducer will be connected. For example, in the case ofa pressure transducer, the macro should be of the form:
1. Macro Message. (Remove weight from transducer and click OK.)
2. Macro Set Units Conversion. (Set to 0.)220

Chart Software3. Macro Message. (Put 100 g weight on transducer and click OK.)
4. Macro Set Units Conversion. (Set to 100, and set units to g.)
5. Macro Message. (The transducer is now calibrated.)Once the macro has been recorded and named, it can be invokedwhen starting to record. The message box will appear, at which time
the user should ensure the transducer has zero grams weight applied toit. When the second message box appears, the user should apply 100
grams weight to the transducer, after which it will be calibrated.

Wait While Sampling
The Wait While Sampling macro command is used to suspend somesteps in a macro until sampling stops. It can be used at any stage in amacro after sampling starts, just by choosing it from the submenu: later
macro steps are suspended until sampling stops, then continue.

▼ ReferStarting Sampling,p. 206The Macro Sampling dialog box lets you suspend all other macro steps
while sampling, or just continue with them while sampling. Sometimes
this all-or-none choice isn’t enough. For example, you might want tostart recording, apply some stimuli (which must be done whilesampling), record the results for a time, and give the user the choice tostart another cycle of stimulation or stop the macro, using a macro
message. You would need the alert box to appear only after sampling
had stopped, not straight after the stimulus, so macro steps would haveto be suspended at that stage. Choosing a Wait While Sampling step
before the Message step allows this refinement.

Stop Sampling
The Stop Sampling macro command is used to stop Chart sampling.
Choose it from the submenu, at any stage in a macro, to provide a user
stop (the Start button doesn’t actually start Chart sampling while you
record a macro, so the Stop button does not appear). In somecircumstances, if you switch back and forth between recording andmonitoring, or change multiple settings such as input ranges, this canresult in the recording of very short blocks between the steps of themacro. Stopping sampling using this macro command before such steps
prevents that problem.

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221

Timed Events
The Timed Events feature allows you to create a list of actions you want
to be performed at particular times from the start of recording, including
setting the analog output or (on specially configured e-corder units)
digital output: once the list is set up, Chart will perform the actions at
the times you have specified. Choose Setup > Timed Events… to set up
a list of timed events. The Timed Events dialog box will appear (Figure7–27).
Click the New button to create a new event row in the scrolling list. To
set the time from the start of recording at which you want the event tooccur, click in the cell of the row in the Time column, and enter the time,in either seconds (any numerical value) or hours, minutes, and seconds(the value in the format hh:mm:ss). The time will be rounded to thenearest second, and expressed as hours, minutes, and seconds. For
example, typing 10 will result in the time being set to 0:10. If you typein 120, the value is converted into 2:00, that is, two minutes from thestart of recording. To set an event to occur at two hours and forty fiveminutes from the start of recording, you would enter 2:45:00. Actions
can be scheduled for the start or end of recording by clicking the Start
or End buttons. Alternatively, you can type in the letter S, for start, or E,
for end, in the time entry field. This is useful for tidying-up tasks, such as
resetting the analog output.

Figure 7–27
The Timed Events dialog
box.

Choose an event from the
pop-up menus in the
Action column
Enter the time after the startof recording that the event
will occur here

Click here to add a newevent row

222

Click here to remove the highlighted row

Chart Software

The timed events list will automatically re-sort rows in chronologicalorder once you have finished a new row. This allows you to add new
events to the list at any time, while being able to view the list in order of
events. You can have two or more events scheduled at the same time:
Chart will execute one after the other as quickly as it can.

Timed Event Actions
Clicking the mouse button when the pointer is in a row in the Action
column opens the Action pop-up menu of events. Three types of event
can be chosen: setting an e-corder output voltage; adding a comment;and (on specially configured e-corder units) applying a digital output
configuration.

▼ Refer
Comments andExclusions, p. 117▼ Refer
Constant Output Voltage,p. 66

Choose Action pop-up > Add Comment… to add a comment to therecording at a specified time. The Add New Comment dialog box willappear. You can type in the comment you want to add, and choose to
apply it to all channels or to a specific channel through the Channel
pop-up menu.
Choose Action pop-up > Set Analog Output… to set the analog output
voltage level from the Output sockets at the front of the e-corder. The
Timed Event Stimulator Output dialog box appears, letting you adjust
the constant output voltage. The amplitude range within which theoutput voltage is set is taken from the Stimulator Constant Output dialog
box.

Figure 7–28
The Add Comment
dialog box.

Note that ‘Analog Output 2’ events are not available with current
e-corder models.
If you have previously defined a list of digital output configurations(only possible on specially configured e-corder units), they will be

Chapter 7 — Customizing & Automating Chart

223

Figure 7–29
The Timed Event
Stimulator Output dialog
box.

included as menu commands at the bottom of the Action pop-up menu,
and can be applied at scheduled times by selecting them as event
actions.
The ‘Repeat Sequence’ command can be used to make the timed events
sequence start from the beginning again. When Chart encounters the
Repeat Sequence action, it goes back to the beginning of the event list
and performs each event in order, starting the sequence from the time
for which the Repeat Sequence was set. This allows you to pause
between repeating events.
The example in Figure 7–30 shows how the Repeat Sequence can beused. It shows the sequence of list events on a time line. The event list in
the dialog box consists of two actions at the beginning of recording,
two actions at 1 minute 40 seconds, and two actions at 5 minutes, atwhich stage the event sequence finishes. By placing a Repeat Sequence
action at 10 minutes, we get the whole sequence repeated again 5
minutes after the end of the last one. Note that the sequence is repeated
immediately after the repeat sequence action.

Editing and Saving Timed Events
To add a new event, click the New button again, and create the new
event you need at the time you want. Once it is entered, Chart sorts theevent list in chronological order again. To change an existing event,select the time or action to change and enter the changes. To remove
an event, click a row to select it (it becomes highlighted) and click the
Delete button. Shift-click or Shift-drag to select contiguous rows, orCommand-click to select or deselect multiple rows singly, for massdeletion. If there are entries in the dialog box, timed events will occur
when you start recording. You have to delete all entries to turn timed
events off.
You can save timed events setups in settings files, or as macro steps. If
you open the Timed Events dialog box while recording a macro, its

224

Chart Softwarestate is recorded as one macro step when you click the OK button, andits timed events are made available and used when the macro isplayed, during a sampling step. If various sets of timed events wererecorded as steps before sampling steps, different lists of actions could
be applied during each macro sampling step.
▼ Refer
Automatic Comments,
p. 226

Figure 7–30
An example of a repeat
sequence and theassociated time line.

The Accuracy of Timed Events
The timed events feature is not intended for uses requiring very highaccuracy. Since it is controlled from the computer, its accuracy will
depend on how busy the computer is: very fast sampling, a slow
processor, or running intensive applications in the background may all
delay it. Holding down a menu while timed events are about to occur
forces a delay until the menu is released. In general, though, it should

0:00

Analog output 0.00 V; pump on
Analog output 2.5 V;
add comment ‘Pump Started’

5:00

Analog output 0.00 V; pump off

10:00

Analog output 0.00 V; pump on
Analog output 2.5 V;
add comment ‘Pump Started’

15:00

Analog output 0.00 V; pump off

20:00

Analog output 0.00 V; pump on

Sequences keep repeating
until recording stopped

Chapter 7 — Customizing & Automating Chart225

be accurate to the second entered. If greater accuracy is required, theautomatic comments feature might be more suitable.

Automatic Comments▼ Refer
Comments andExclusions, p. 117

The automatic comments feature lets you generate predefined comments
while sampling. By setting up a list of comments (in the AutomaticComments dialog box) that correspond to certain events, you can haveChart automatically insert the corresponding comment when the event
occurs. The events include certain states or changes of state of thee-corder digital inputs, external trigger, or stimulator, so that you cankeep notes of all such changes during automated recording. The timingof automatic comments is very accurate (unlike the timed events
feature), so it is particularly suitable for this. The events also include
using Function keys, so that a single keystroke can be used to enter along comment. If you have external equipment to monitor or routine
analyses to run, then automatic comments can save a lot of time.
Choose Setup > Auto Comments… to create a list of automaticcomments. The Automatic Comments dialog box appears. The dialog
box gives some feedback about the e-corder hardware. The state
indicators at the top of the dialog box show if the external trigger (Ex)is on (highlighted) or off (plain), so that you can observe the effects
while setting up automatic comments.
To create a new automatic comment, click the New button to add a
new row to the scrolling list. Type the comment text in the Comment
Text column of the row. The comment can be applied to any of theavailable channels or to all channels, by selecting the appropriate itemfrom the pop-up menu in the Chan column.
The pop-up menu in the Event column lets you choose what causes thecomment in a row to be added. As a shortcut, you can click one of thenumbered state indicators to apply that bit to a selected row. The popup menu also has an Any Bit option. When this option is selected,
Chart adds a comment when any digital bit changes.Those rows where
the comments are activated by digital input bits or the external trigger
will have a state change icon in the second column. Click the statechange icon to toggle it up or down, showing the input signal change
to cause the comment to be added to the recording: up for an off-to-on

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Figure 7–31
The Automatic Comments
dialog box.

State indicators, shows
red when on

Enter the comment here

Choose the event that adds the Click to togglecomment from this pop-up menu the state icon

Choose the channel in which the comment
will be recorded from this pop-up menu

transition (from a low to a high state), and down for an on-to-off
transition (from a high to a low state).

Function Keys

▼ Refer
Tool Bar, p. 190

You can choose one of the 15 Function keys (F1 to F15) in the Eventcolumn, for use with an extended keyboard. Then rather than typing incomments in the text entry area at the bottom of the Chart window
while recording, you can simply press the key to add the assigned
comment, saving both typing and time. This is useful if you are doing aroutine experiment or have typical things you note about recorded
data. Note that Function keys assigned to a button on the Tool bar
override those same keys assigned for automatic comments.

External Trigger, Stimulator▼ Refer
Triggering, p. 55

If you choose the external trigger (Ext Trigger) in the Event column, theevent comes from an external source connected via the Trigger
connector on the front of the e-corder. Chart adds the matchingcomment when a TTL voltage pulse (or contact closure) activates theexternal trigger, at the start or end of the event, depending on thewhether the state change icon is up or down (you could measure event
width by using both).

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227

▼ Refer
The Stimulator, p. 60

If you choose the stimulator (Stim Mark) in the Event column, Chart will
add the matching comment when it starts a stimulus. The comment is
added at the start of each step or ramp. If continuous (repetitive)
stimulation is chosen, the comment is added at the start of each pulse,or the start of each cycle for triangle or sine modes; otherwise it isadded at the beginning of the set number of pulses or cycles.
Stimulation starts when sampling starts, for repetitive stimulation, so acomment will be added at time zero. This feature helps to avoid having
both to enter a comment and apply stimulation manually at the sametime. It works at any sampling rate, up to a stimulus frequency of about
10 Hz. Unlike the stimulus marker, it won’t add a data spike to achannel’s waveform.

Repeating Automatic Comments
You can have more than one comment attached to the same event, inwhich case Chart simply cycles through them. You might want toindicate ‘first heating phase’, ‘second heating phase’ in monitoring a
digital input, say. Chart takes account of the state change icon in thesecond column of the dialog box, so that, for instance, the start andend of an external trigger pulse are treated as separate events.
Repeated automatic comments can also be numbered to help keep
track of them. If you set up an automatic comment that contains the #character, then when this comment is added, an incrementing number
replaces the #. An automatic comment ‘Pump on #’ would give ‘Pump
on 1’, ‘Pump on 2’, and so on in the recording. Up to ten independent
lists of numbered repeat comments can be generated, by adding a
number (0 to 9) immediately after the # (#0 is the same as just using #by itself). To set up a comment that gives the current digital input byte,
use #D in the comment text column.

Editing and Saving Automatic Comments
To create a new automatic comment, click the New button. To change
an existing comment, select the text and type over it; to change theevent, choose another from the Event column. To delete an automaticcomment, click a row to select it (it becomes highlighted) and click the
Delete button. Shift-click or Shift-drag to select contiguous rows, orCommand-click to select or deselect multiple rows individually, for massdeletion. If there are entries in the dialog box, automatic comments will

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be applied as set up when you start recording. You have to delete all
entries to turn automatic comments off.
You can save automatic comments setups in settings files, or as macro
steps. If you open the Automatic Comments dialog box while recording
a macro, its state is recorded as one macro step when you click the OK
button, and its comments list is made available and used when themacro is played, during a sampling step. If various sets of automaticcomments were recorded as steps before sampling steps, different listsof comments could be applied during each macro sampling step. Tochange the list, you must first stop recording.

Choosing a Connected e-corder
Usually a single e-corder is connected to a computer. It is possible, touse multiple copies of Chart, and connect multiple e-corders to one
computer. Each copy of Chart can be assigned to work with anindividual e-corder.

e-corder Startup
You control the way in which the software starts up by changing thedefault settings in the e-corder Startup dialog box. Choose Chart >Preferences > e-corder Startup… to open the dialog box.

▼ Refer
Figure 1–2, p. 4

If the top radio button in the dialog box is on, the software always
starts in analysis mode without even looking for an e-corder; this avoidsthe ‘e-corder Unavailable’ dialog box, and is useful if you are using
Chart on a computer without an e-corder attached (for example toreview and analyse existing data files).

Figure 7–32
The e-corder Startup
dialog box.

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229

Choosing and Naming an e-corderIf you have multiple e-corders connected to your computer then you canhold down the Option key as Chart starts up to open a dialog box thatlets you choose which one to use. This could be useful if you have thee-corders set up for particular tasks and don’t want to disconnect orreconnect them.

Figure 7–33
The Choose e-corderdialog box.

Figure 7–34
The Change e-corder
Name dialog box.

To choose a connected e-corder, click it in the scrolling list. Click the
OK button to start up Chart with the chosen e-corder. If you click
Cancel, a dialog box appears letting you choose to work in Analysis
mode.
You can also name an e-corder selected in the scrolling list by clicking
the Change Name… button. A dialog box appears: enter a name in
the text entry box to replace the default (model) name and click the OK
button to apply it.
Naming an e-corder is useful if you have several e-corders of the same
type. The e-corder stores the name and can be identified by it whenever
it is connected.

230

Chart SoftwareIf you do record on multiple copies of Chart simultaneously, you may
need to synchronize the recording. To do this, use the same triggering
setup in each Chart file, and use an external triggering device
connected in common to the trigger input at the front of each e-corderto start recording.

Chapter 7 — Customizing & Automating Chart

231

232

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A

P

P

E

N

D

I

X

A

A Menus & Shortcuts
Menus
The menus shown here are the default settings, and your copy of Chart
may be set up differently, since Chart menus can be extensively
customized. Chart has seven menus: Chart, File, Edit, Setup,
Commands, Macro and Window; macros, Chart extensions can add
more. Some of the menu commands shown will change or be disableddepending on the active window and what, if anything, is selected. An
ellipsis (…) after a menu command indicates that it opens a dialog box;
a tick to its left indicates that it is currently active; and a keyboard
equivalent, if there is one, is shown to its right.

Figure A–1
The Chart menu.

Display system and hardware configuration information
Customize Chart options (see submenu)
Use Mac OS X services
Hide the Chart Application
Hide other applicationsShow all applications
Quit Chart

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233

Choose how Chart looks for e-corderFigure A–2
The Preferences
submenu.

Choose trigger event: voltage level or contact closure
Set up the Tool bar
Choose shape of the Waveform Cursor
Modify Chart menus
Modify various Chart features and settings
View, add and remove Chart licenses
Choose which Chart extensions to use
Change the size of the memory cache
Choose to store data on disk or in memory
Save current settings as default settings

Figure A–3
The File menu.

View a list of your experiment and supporting files
Create a new Chart file
Open an existing file
Append an existing file to the current file
Close the current file
Save the current file
Save file with a new name, or location, or format
Save the current selection as a separate fileSet up Chart to save automatically
Set up file information to search for
Search for Chart files by file information or comments
Set up page size and so on to suit the printerPrint all data (or active window)

Figure A–4
The Edit menu.

Undo previous action (if possible)
Cut selected data to the Clipboard
Copy selected data to the Clipboard
Paste selection
Clear selection
Select all data
Clear all data in a channel
Show Clipboard

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Figure A–5
The Setup menu.

Modify display settings, grids, lines, etc.
Change channel display and input settings
Set up what triggers and stops sampling
Auto-zero any connected Bridge or GP Amp
Set up the stimulator
Display the stimulator control miniwindow
Set the stimulator constant output voltage
For future e-corder models
For future e-corder models
List actions to be performed at certain times
Add predefined comments with a shortcut key

Figure A–6
The Commands menu.

Comment on the selected point or area
Set Marker position (see submenu)
Add information on selected point or area to Data Pad
Set scale zero to active point, or average of selection
Revert to settings before baseline set up
Exclude the selected point or area
Auto scale the amplitude axis in all channels
Find and select data matching user criteria
Find and select next data matching user criteria

Figure A–7
The Set Marker submenu.

Appendix A — Menus & Shortcuts

Set Marker to lowest point in selection
Set Marker to highest point in selection
Set Marker to left-most point in selection
Set Marker to right-most point in selection

235

Figure A–8
The Window menu.

Display Notebook window, for general notes
Return to or open the Chart window
Display a selection in the Zoom window
Display the X–Y window
Display the Comments & Exclusions window
Display all data for a channel in a miniwindow
Display the Data Pad, for setup or analysis
Display a time/date/value miniwindow
Display data logged from DVM miniwindows
Display the Spectrum window

Figure A–9
The Macro menu.

Start or stop recording a macro
Choose macro control actions (see submenu)
Delete a macro from the current list of macros

Redraw the screen during playing of macro

Figure A–10
The Macro Commands
submenu.

Pause the macro for a set time
Set an audible alert using the System sounds
Display a message dialog box
Speak a written message
Add an AppleScript as a macro step
Repeat some action while selection is within a block
Repeat some action within a selection
Select regular periods of data to manipulate
Select each block of data to manipulate
Start a repeat sequence
Finish a repeat sequence or repeat select sequence
Change the scale units within a macro
Leave remaining macro steps until sampling finishes
Stop Chart sampling

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Shortcuts and Tips
Actions in general apply to the Chart window. Keyboard shortcuts formenu commands can be added, changed, or assigned to user-defined
actions (menu commands are listed alphabetically by shortcut so thatyou can see at a glance which keys have been used). Some of theshortcuts shown will change or be disabled depending on the active
window and what, if anything, is selected.

Menu Commands
Table A-1:

ActionShortcutChart keyboard andother shortcuts: thetable is divided into
named groups ofrelated shortcuts forconvenience.

Select all

Command + A

Clear selection

Command + B

Copy to Clipboard

Command + C

Add information to Data Pad

Command + D

Mark data to be excluded from analyses
and so on

Command + E

Find and select data matching user criteria

Command + F

Find and select next data matching user criteria

Command + G

Hide Chart

Command + H

Add comment

Command + K

Comments & Exclusions window

Command + L

Overview miniwindow

Command + M

New Chart data file

Command + N

Open file

Command + O

Print

Command + P

Quit Chart

Command + Q

Start/stop macro recording

Command + R

Save file

Command + S

PasteCommand + V

Close active window

Command + W

Cut selection

Command + X

Channel Settings dialog box

Command + Y

Undo/redo

Command + Z

Appendix A — Menus & Shortcuts

237

Navigation
ActionShortcut

Scroll left or right

Left or Right arrow

Go to previous or next block

Option + Left or Right arrow

Go to start or end of file

Command + Left or Right arrow

Manually scroll data display
area

Option + drag the area (Chart or
Zoom window)

Auto-scroll data display area

Option + drag the area, let go whiledragging

Go to a block

Click the block button

Go to a comment

Double-click comment in Comments& Exclusions window

Go to any section of data display area

Drag highlighted region in Overview miniwindow

Center off-screen selection

Command + click in Zoom window

Selecting Data

238

ActionShortcut

Set active point in a channel

Click in channel

Set active point over all channels

Click in Time axis

Select area in a channel

Drag in channel

Extend selection in a channel

Shift + click in channel

Select full height of a channel

Command + drag in channel

Select area of additional channel

Shift + drag in additional channel

Select full height of additional
channelCommand + Shift + click in additional channel

Select same relative height ofadditional channel

Option + Shift + click in additional
channelSelect area over all channels

Drag in Time axis

Extend selection over all channels

Shift + click in Time axis

Deselect selected channel

Shift + click in channel

Select a block

Press the block button and choose
Select Block, or double-click inTime axis
Chart Software

Starting up Chart
ActionShortcutChoose the extensions to load

Hold down Space Bar while Chart
starts up

Use the default settings for asession

Hold down Command key while
Chart starts up

Display
ActionShortcut

Revert shifted or stretched verticalscale

Double-click in Amplitude axis

Cycle through scale display
modes

Double-click repeatedly in Amplitude axis

Hide split bar (show Chart window with one pane)

Double-click split bar

Give each channel the samearea

Double-click any channel separator

Overlay adjacent channels

Option + click their channel separator

Separate overlaid channels

In Channel Settings dialog box,
turn on their Separator checkbox

Move Tool bar

Shift + drag Tool bar

GeneralActionShortcutSelect/deselect adjacent items in list

Shift + click in list

Select/deselect separate items in list

Command + click in list

Move between text entry fields in dialog
boxes

Tab

Accept (OK) dialog boxes

ReturnCancel dialog boxes

Esc key or Command + .
(period)

Appendix A — Menus & Shortcuts

239

Miscellaneous

240

ActionShortcutStart/stop sampling (on most systems)

Command + Space Bar

Stop process (sampling, macro playing,drawing, etc.)

Command + . (period)

Bring up last chosen channel calculation
dialog box

Command + =Special access to dialog boxes (Menu,
Save As, etc.)

Command + \ or Control + Command + 1

Delete selection

DeleteAdd information on a data point to Data
Pad

Double-click in channel

Show recording settings information for achannelClick Channel Status diamondShow block information summary for achannelClick in data display
area of channel

Make channel-specific comment whilesampling

Tab, type channel number, comment, thenReturnMake non-specific comment while sampling

Tab, type any letter,comment, then Return

Send Marker home

Double-click Marker, or
click Marker box

Transfer data from display to initial voltage values in Units Conversion dialog
box

Double-click in its data
display

Activate Stimulator Panel buttons to startor stop stimuli

Option + Space Bar

Maximize image in Page Layout dialog
box

Double-click image

Set/Remove baseline over whole channel

Command + choose
Commands >Set/Remove Baseline

Turn channel and all below it off or on

In Channel Settings dialog box, Command +click the On checkbox

Chart Software

Action

ShortcutTurn channel and all below it off, or thosewith visible data on

Command + choose
Channel Function pop-up> Turn Channels Off/On

Apply channel calculation permanently toa channel

Command + choose
Channel Function pop-up> Apply Calculation…

There are many other general Macintosh shortcuts, of course, such as
the set available in the Open and Save dialog boxes. See theMacintosh system help for details.

Appendix A — Menus & Shortcuts

241

242

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B Troubleshooting

B

Technical Support
Chart has been extensively tested to make sure that it runs smoothly andwithout difficulties. Occasionally, however, problems may arise orsomething unexpected may occur. The second part of this appendix
gives a list of possible problems and likely solutions: you should lookthere first to see if your needs are addressed specifically. (This can saveyou some money in telephone calls or faxes!)
If you are experiencing difficulties with Chart that are not covered inthis manual, or you need technical assistance with your e-corder system
in some form, then eDAQ and its authorized distributors are glad to
help. The About Chart dialog box gives access to contact addresses
and information on the system and hardware configuration. Choose
Chart > About Chart… to open it.

Figure B–1
The About Chart dialog
box.

Release date
Click these buttons for
information on contacts,
Chart extensions andhardware configuration

Chart Software243

Dealer and Distributor Information
If you need help or information from an eDAQ distributor, click the
Telephone button to open the eDAQ Contacts dialog box. Feel free to
get in touch with your local eDAQ distributor to discuss hardware andsoftware requirements generally, and find out more about the latest
releases, upgrades, and software maintenance information. You canalso visit the eDAQ web site for general information of this nature.

Click on links

Figure B–2
The eDAQ Contacts
dialog box.

The dialog box should have up-to-date contact information. Click in thescrolling list on the left of the dialog box to select your country, or thenearest one to it, and contact information will appear to the right. Click
the Copy button to copy the information to the Clipboard, to savetyping it out.
The Web and email addresses in this dialog box, and the Web
address are hyperlinks. Clicking a link will open your web browser andtake you to the web site, or open your email program and fill in themailing address for you.

System Configuration Information
In general, we will need quite specific information about your hardware
and software to help to isolate and to solve problems effectively. Since
this type of information can be tedious to collate, Chart does it all foryou. Click the computer button to open the About this Macintosh dialog
box.

244

Chart Software

Figure B–3
The About this Macintosh
dialog box.

The Chart tab lists detailsof the software version
and computer

The Hardware tab lists
details of the e-corder,
and any eDAQ Amps or
pods connected

The dialog box has four tabs. The Chart tab gives information on which
version of Chart is running, together with information about yourcomputer and operating system. The Licenses tab lists your current
license for Chart and you have installed (this information is alsoavailable in the License Manager dialog box). The Extensions tab lists
installed Chart extensions, if any. The e-corder tab contains details ofyour e-corder and how it is connected, as well as any connected eDAQ
Amps and pods. If the e-corder has any pod connections without podsconnected, they are listed as ‘Input Amplifier’. Click the Print… button
to print a tab, or the Copy to Clipboard button to copy the text for
pasting into an email, letter or fax to your eDAQ distributor.

Appendix A — Troubleshooting

245

General
We welcome customer comment. If you have comments or suggestions
you would like to make about the Chart Application or this manual,please feel free to write to us directly at info@eDAQ.com. We value
your responses, and they are taken into account when future releases
are being worked on.

Solutions to Common Problems
Chart has an extensive array of dialog boxes which appear in mostcases where problems arise. Very often they will suggest appropriate
courses of action. Otherwise this section of the manual may prove
useful.

Starting Up
Startup errors are mostly hardware problems, and are dealt with indetail in your e-corder Manual (supplied as a pdf format file) but arebriefly covered here.
The computer can’t find the e-corder• The e-corder is off or the power is switched off at the wall, thepower cable is not connected firmly, or a fuse has blown. Checkswitches, power connections, and fuses.
• A poor connection between e-corder and computer, or bad cable.
Ensure that the cable is firmly attached at both ends and try again. If
there is still a problem, try a new cable.
• The software preferences are set to start up in analysis mode or
only using a certain connection. (e-corder settings are common for
Chart and Scope, so this could have been set in either program.) If
the ‘e-corder Unavailable’ dialog box has appeared, click the
Options… button in it to open the e-corder Startup dialog box sothat you can change the settings. Otherwise choose Chart >Preferences > e-corder Startup… to open the dialog box.
Chart ‘hangs’ or gives an alert on start-up• It may be that the copy of Chart on your computer has become
damaged in some way. Try reinstalling Chart from the original CD.
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Chart Software

Chart starts up with strange settings and macros• If you started Chart by opening a settings file or a data file withcustom settings start up again from the Chart program itself.
• If the startup settings have been customized start up Chart with its
default settings, by hold down the Command key as you open thesoftware. Release the key when an alert box appears.
• To revert to the default startup settings, choose Chart >Preferences > Startup… and click Clear in the dialog box thatappears. The next time Chart starts up, it will open with the default
settings.

Interface Problems
Some data display areas show gray
• Chart channels show gray if they are turned off while recording,or if they are monitoring rather than recording, or if they are verythin. Most dialog boxes and windows require a selection of data in
the Chart window to display a waveform (not just an active point).
The X–Y window needs to have the x and y channels selected to plot
against each other. The Zoom window and Overview miniwindow
show gray if they were stopped while drawing.
• Turn the channel on, switch from monitoring to recording, or dragthe channel separator to widen it; select data in the Chart window if
there is no selection; click x and y numbered buttons in the X–Y
window to get an X–Y plot; click the display area in the Zoom
window for it to redraw; click the display or a numbered button in
the Overview miniwindow for that to redraw.
The Time axis shows very large or negative values• The file with which you are working is an old one with new data
recorded in it, or one created by appending files or selections, andthe time is displayed from the start of the record. Chart remembers,
but does not display, the date and time of all recordings. Hence a
section recorded before the one at the start of the file andsubsequently appended to it, say, will appear with a negative time
relative to the start of the record. Very large values to the right of theTime axis reflect a large lag between the time the record wascreated and the latest recording.

Appendix A — Troubleshooting247

• If the values are a problem, simply change the time mode display
to show time from the start of each block (the default setting).
Defined units display strangely• Chart will deal with a unit prefix correctly only if it is chosen fromthe Prefix pop-up menu in the dialog box for defining units: if
defined as part of a unit, it is ignored. Take a tesla (T), the standard
unit of magnetic flux density. If you type in mT as one word with noprefix, then Chart will display a waveform of a thousandth of a mT
with units of mmT. If the prefix m were chosen, Chart would scale
the unit prefix properly, to give measurements in µT.
▼ Refer
Choosing Unit Names,
p. 50• The indentation of defined units in the Unit pop-up menu in the
Units Conversion dialog box shows if a prefix has been usedproperly.
Commands seem to have no effect, or a strange one• If commands do not work in all circumstances, or if you have noselection or active point in the Chart window (for example, you
cannot use commands to do with selections or active points, such asadding data to the Data Pad or printing a selection) then make sure
you have a selection or active point in the Chart window, orotherwise have things appropriately set up.
• If Macro recording has been turned on, then you record what you
are doing rather than actually doing it. Choose Macro > Stop
Recording… and discard the macro.
Keyboard shortcuts don’t work, or do strange things• Menu commands may have been deleted, or keyboard shortcuts
reassigned to other menu commands or macros. Look at the menus
and compare them with the tables in Appendix A. See below for
resetting procedures.
Menus, controls, or settings don’t match those in this guide• If you started Chart by opening a settings file or a data file withcustom settings start up again from the Chart program itself.
• If the startup settings have been customized start up Chart with its
default settings, by hold down the Command key as you open thesoftware. Release the key when an alert box appears.

248

Chart Software• To revert to the default startup settings, choose Chart >Preferences > Startup… and click Clear in the dialog box thatappears. The next time Chart starts up, it will open with the default
settings.
• Chart extensions may also add menus and alter some options. To
start up Chart and choose which Chart extensions load, hold down
the space bar while Chart opens. Release the key when the
Extensions Manager dialog box appears. To stop particular Chart
extensions being loaded at all, move them from the Extensions folder
into the Extensions (Unused) folder (or make another such folder tosuit your needs).
I’ve altered menus and locked myself out, can’t save, and so on• Type Command-\ or Command-Shift-1 to open a dialog box thatallows special access to menu, Tool bar, control, startup settings andsaving options.
Dialog boxes don’t appear where I want themChart dialog boxes usually appear on the main monitor (the one withthe menu bar). There are times, however, when you want one toappear on a secondary monitor, for instance, if that monitor is color
and you are changing display colors.
• Chart usually opens dialog boxes on the monitor where thepointer is positioned. Move the pointer to a secondary monitor anduse a keyboard shortcut to open the dialog box there (if there is no
shortcut, add one or define a macro with one to do it).
I keep getting alerts saying the sampling rate is too fast
▼ Refer
Setting Sampling Rates,
p. 36
Performance, p. 31• Chart has a maximum continuous sampling rate of 200 000
samples per second on one channel, 80 000 rates on two, and
40 000 on three or four. The external trigger can’t be used at asampling rate of 200 000 /s. Turn off the external trigger whensampling at 200 000 /s, reduce the number of channels used at
fast rates, and so on.
• Faster computers allow better sampling rates on more channels,
slower computers may limit recording speed. A USB 1.1 computer
may not handle the very fastest sampling rates.

Appendix A — Troubleshooting249

• Turn off unused Chart extensions, channels, computed inputs, andfilters. This will decrease the workload for the computer.
• Channels do not need to be visible to record data, so check thatany bunched up in the Chart window are actually off.
• Change the size of the memory cache (choose Chart >Preferences > Memory Cache… to open the Memory Cache dialog
box.
• If the Chart window is large and the display is at a high color
depth, more processing power is needed to draw it. Shrink theChart window and reduce the color depth of the display.
• Miniwindows floating over the data display area will slow down
sampling rates, especially if they overlap multiple channels.
• Keep miniwindows away from the data display area, turn themoff, or make sure they keep to only one channel.
• Background activities (other programs and devices) can reduce
the ability of the computer and connection to cope with recorded
data. Turn off programs other than Chart that could slow down or(as in the case of electronic mail) interrupt data sampling, and don’t
use too many devices at once, especially on a USB chain.
• When recording to disk, ensure that your disk is not too full and is
not fragmented: this slows down the speed of writing to disk.
• Recording to RAM (if you have enough) may be better for slower
computers.
Nothing seems to be recording• The Record/Monitor button (bottom right of the Chart window, by
the Start button) may be set to monitor; there will be a cross throughit if this is so, the Recording Status indicator (above the Time axis)
will read ‘Not Recording’, and incoming channels will be grayed.
Click the Record/Monitor button to make the cross disappear, andthen data shown on screen will be recorded normally. If the button is
not visible, then use the Controls dialog box (Edit > Preferences >Controls…) to show it.
• Chart may be recording, with nothing visible going on. This
happens if Chart is reviewing rather than scrolling. If so, theScroll/Review button will be highlighted (depressed), the Recording
Status indicator will read ‘Recording’, and the scroll bar replaces

250

Chart Softwarethe Comments bar. Click the Scroll/Review button to change its state
and record normally.
• You may be sampling at a very slow rate with a highly
compressed horizontal scale, so that it takes a long time for data toappear. Check sampling rates and View buttons, and change asneeded.
• Chart may be waiting for a trigger event or its internal timer: inthis case the Recording Status indicator, above the Time axis, will
read ‘Waiting for trigger’ or ‘Int. Timer’ or something similar. Values
in the Range/Amplitude display may still change with the input
signals. The e-corder also indicates it is waiting for a trigger. Supply
the necessary trigger event, or choose Setup > Trigger and set the
Event in the Trigger dialog box to User.
The computer ‘hangs’ while recording, or there is data loss
• There may be a poor cable connection between the e-corder andthe computer, or a bad cable. Ensure that the cable is firmly
attached at both ends and try again. If there is still a problem, try a
new cable.
• Network connections or a strange system extension could also be
at fault.Check your network connections and system extensions. It
recommended to avoid using the intenet, email, or other network
connections whilst collecting data.
Running out of memory• You may be recording to RAM rather than to disk. Record to disk
instead — choose Chart > Preferences > Data Buffering…
• Chart extensions use up allocated memory and may slow downChart as well: only use those that you need. Turn off unnecessary
Chart extensions (choose Chart > Preferences > Extensions… to get
the dialog box), then quit and restart Chart.
• Chart uses a reasonable amount of memory for an off-screen
buffer: if the Chart window is large, more memory is used,especially at increased color depths. Shrink the Chart window andreduce the color depth of your display.

Appendix A — Troubleshooting

251Comments are truncated when printed• Turning off the Show Times checkbox in the Comments window
will allow a little extra space for printing comments either at the endof a Chart file or on their own.
• Comments are only designed for short notes, but if they are still
too long to print after trying the above remedies, then transfer themas text to a word-processing program.
Printing is very slow
• Reduce the color depth of your display, and compress your fileusing the View buttons to minimize the number of pages that must
be printed. Ensure that you are using the latest printer driver.
• The Page Setup options affect printing speed. Experiment withthem to see which give best results. For a PostScript laser printer,
Substitute Font should be on. In general, the Faster Printing option ismost useful for older, slower computer systems; new systems should
print Chart files more quickly with it off.
• When setting the Layout options in the Print dialog box leave theLayout option at printing one page per sheet, since the scaling canbe quite slow.
The quality of the hard copy using faster printing should be sufficient formost purposes except publication. Printing speed depends on hardware
as well: the faster the computer and printer, the faster that material canbe printed.
Macros behave unexpectedly• Make sure that you have the right macro, not a different one of
the same name (in the case of name conflicts, the latest macro
loaded into memory is used).
• Check that you have the steps and effects recorded somewhere,
and that you haven’t misremembered them — it is very easy to do.
• If the macro is a new one, it is possible that a step was notrecorded correctly, and in particular, that a repeated sequence wasended in the wrong place. Try recording it again.

252

Chart SoftwareI have macros in files where I don’t want them
• A macro, once created, floats around in memory until it isdiscarded or you save a file, whereupon a copy is saved with thefile. If you have opened many files containing macros, you may end
up with a lot in memory.
• Ensure that the Discard Existing Macros checkbox in the Opendialog box is on. This prevents accidental accumulation of unwanted
macros as you open files.
• Delete unwanted macros using the Macro > Delete Macro… (thisaction merely removes macros from memory) and then save the file
you want free of them (this removes them from the file).
I created a macro, but lost it on quitting Chart• Macros are saved when a file is saved. The macro may havebeen attached to another file, or lost if you didn’t save a file before
quitting Chart.
Chart can’t seem to recognize a Chart file
• You may be using an early version of Chart with a later version’s
file. File formats can change between versions, so software cannot
always read later files. Newer software updates files when it opens
them. Always use the latest version of Chart.
• The file may have become corrupted, possibly through disk
damage.Use disk-checking software to find and fix the problem.
• If you back up files onto a computer using the Windows OS, becareful. Try to make sure the files are only handled from the Mac
OS. Windows systems typically do not understand Macintosh files,
and may discard information such as the file type or resource fork if
the files are manipulated by the OS or an archiving program.
• Chart files should still be recoverable even if the file type andresource fork are lost. It may be necessary to add “.cfm” to the filename in the Finder to force Chart to recognize it as a Chart file.
Chart quits unexpectedly, crashes, or freezes• If Chart quits unexpectedly or crashes, or the pointer freezes, thenthere may be a Mac OS system problem. See the guide to the Mac
OS that came with your computer for details on this problem andhow to deal with it.
Appendix A — Troubleshooting253• The file you are using may have become corrupted, possibly
through disk damage. Use disk-checking software to find and fix the
problem.
• Try reinstalling Chart from the original CD.
• Check your disk with anti-viral software. If you find a virus, you
should check all potentially affected computers, disks, and backups,
and eliminate the infection.
• Check to see if the problem occurs again. If so, note down what
you were doing as fully as possible (use the About this Macintosh
dialog box, and add any relevant details, such as sampling rates
and the like) and notify eDAQ.

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Appendix A — Troubleshooting

255

Note
Chart checks itself on
startup for damage orvirus infection, and will
present an appropriate
alert box if it detects a
problem. (Files are notchecked, though.)256

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C Technical Notes

C

Calculation Details
Depending on your data it may be useful to know the mathematicaldetails behind some of Chart’s analysis functions, in order to get thebest use out of them. This appendix gives details of the algorithms usedby the Spectrum window. It also explains why the results of computed
input functions and corresponding channel calculations may differ.

The Spectrum Window FFT
Physical phenomena can be described in terms of time or its inverse,
frequency. The functions describing a phenomenon in the time domain
or frequency domain are effectively equivalent, and one can switch
between them using certain linear transforms. Spectrum uses a discrete
Fast Fourier Transform (FFT) algorithm to convert data from time tofrequency domains.
Spectrum divides the data into segments, with the number of data
points in each segment equal to a power of two (a requirement of thealgorithm): this is the FFT Size shown in the Spectrum Settings window.
Once a selection made in the Chart window is divided up into
segments of this size, the transform is applied to each segment tocalculate its spectrum. The spectrum plotted is the average of thesepartial spectra. Averaging improves the amplitude accuracy over alarge selection.

Chart Software257

If the number of data points selected does not divide up exactly into awhole number of FFTs, and the selection is unadjusted (‘Use Current’ ischosen in the settings), or if not enough points exist within a data block,the remainder is padded with zeroes, which are added to the right sideof the remaining data points of the selection before the transform isapplied. The Spectrum window shows selection information above thegraph area: the number of FFTs, the number of data points per FFT, andeither the number of padded points (if any), or whether the selection
was adjusted to give an integral number of unpadded FFTs. (Thisinformation changes with Spectrum’s settings.)

Selection = 968 data points

Figure C–1
A selection of 968 data
points with FFTs of 256(no overlap) divides into
3 FFTs with 200 left over,so Spectrum adds 56
zeroes at right to pad out
data for the fourth FFT.

256

256

256

200

FFT

FFT

FFT

FFT

Average+56 padded
zeroes

Display

Spectrum’s Implementation of the FFT
The treatment here is only a summary; see Press et al.1 for a more
complete discussion. Chart takes samples at discrete intervals set by the
sampling rate. If we look at a sequence of N consecutive samples,
where N is an even number (for simplicity), with a sampling interval ∆,we can define a function hk ≡ h(tk) where the time when sample k istaken, tk ≡ k∆, and k is the series 0, 1, 2, … N–1. It is assumed that thefunction that describes the sampled points is representative of the entire
waveform, that is, that there is some form of periodicity. The FFTtransforms these N discrete samples in time, with h voltage (or derived
units), to N discrete samples in frequency, with H frequency amplitude.
The frequencies can be assigned the discrete values fn = n/N∆, where

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n is the series –N/2, …, N/2–1. The discrete Fourier transform of the
N points hk is defined by:
N–1

H n ≡ ∑ h k e 2πikn ⁄ N
k=0This transform maps N complex numbers hk into N complex numbers
Hn (for data measured from physical phenomena, such as Chart deals
with, numbers hk are real with the imaginary part set to zero). Hn are in
the frequency domain, since the horizontal axis is measured in units of1/∆, which represents frequency. Zero frequency corresponds to n = 0;
positive frequencies correspond to values 1 ≤ n ≤ N/2–1. The function
can be seen to be periodic in n with period N, with H–n = HN–n forvalues of n other than zero. One can let the n in Hn range from 0 to
N–1 so the correspondence between k in the time domain and n in thefrequency domain is more obvious, but we don’t for this treatment.
If Re(Hn) and Im(Hn) are the real and imaginary parts of the nthfrequency component of the FFT, then the power (modulus squared) of
the nth frequency component of the spectrum may be expressed as:
2

2

Re ( H n ) + Im ( H n )P ( n ) = 2 -----------------------------------------------N

The amplitude (modulus) of the nth frequency component of thespectrum is then:A(n) =

2P ( n )where the factor 2 converts from RMS value to amplitude.
Note that the accuracy with which FFT can resolve frequencies depends
on the sampling rate 1/∆, and the number N of points sampled. If afrequency reading is not an integral multiple of 1/∆N Hz, then it will
be resolved into peaks above and below that value, distorting theresult. Keeping N at a large value minimizes these problems.

Windowing Functions
The FFT assumes that samples represent an integral number of cycles ofa periodic waveform. The assumption of perfect periodicity can lead toproblems. If, say, the first and last values of a waveform seen in thesampling window do not join smoothly together, then a spurious

Appendix A — Technical Notes

259

frequency reading will be detected at the edge of the sampling windowby the FFT: this is known as an edge effect. Windowing functions
reduce the importance of data at the edges of the window used by the
FFT, thus preventing spurious peaks arising from edge effects. If awindowing function is used, the original data are multiplied by thewindowing function w(k) to weight them:
N–1

1
H n ≡ ---------- ∑ w ( k )h k e 2πikn ⁄ N
w av
k=0

Four of the more useful windowing functions have been provided inSpectrum, as shown in Figure C–2 (there are many others, as discussed
in Reference 1). To compensate for the attenuation due to a windowing
function when one is in effect, all power values P(n), calculated asshown earlier, are multiplied by a factorN---------------------2∑ w(k)k

Cosine Bell window

Figure C–2
Windowing functions
used by Spectrum andtheir definitions: k is avalue between –N/2
and N/2–1, where N is
the number of sampled
points.

Hamming window

1

1

0

0.08
0

–N/2

0

N/2–1

2πk
w ( k ) = 0.50 1 + cos  ----------
 N 

–N/2

Welch window
1

–N/2

0

N/2–1

2πk
4πk
w ( k ) = 0.42 + 0.50 cos  ---------- + 0.08 cos  ----------
 N 
 N 

260

N/2–1

2πk
w ( k ) = 0.54 + 0.46 cos  ---------- N Blackman window
1

0

0

0

–N/2

0

N/2–1

(k – N ⁄ 2) 2
w ( k ) = 1 –  -------------------------- N⁄2 Chart SoftwareZero-padding
If Spectrum’s internal data selection is not a multiple of the chosen FFTsize, the data size is extended to the right by padding it with zero
values. Windowing functions are applied to the true data, before its
length is extended by zero-padding.

Computations with Computed Input
Functions and Channel Calculations
There is some overlap in functionality between computed inputs andchannel calculations. The cyclic rate and cyclic amplitude computed
input functions are duplicated as options in the Cycle Variables channel
calculation (except for Counter, which is represented by the Cycle
Variables Data Pad functions Event Count and Cycle Count); theDifferential computed input function is duplicated as the Differential
channel calculation; and the five integral computed input functions havecorresponding options in the Integral channel calculation. (Note,however, that the two smoothing computed input functions provide a
different computation to the Smoothing channel calculation.)
In addition to differences in the way computed inputs and channel
calculations are used (computed inputs are used online while channel
calculations are principally used offline, for instance), the results yieldedby the two may differ. There are three factors, which may or may notcontribute depending on the type of computed input/channel
calculation used. Which factor affects which type of computed
input/channel calculation is summarized in Table C–1.
1. The sampling rate used for computation may differ. Computed
inputs will always have a precision based on a sampling rate of2000 Hz or higher — the speed at which Chart samples internallyfor these computations, even if a lower sampling rate is chosen.
Since channel calculations operate offline, they are based on thesampling rate set for the channel. If the sampling rate is≥ 2000 Hz, the precision of results calculated using computed
inputs and channel calculations will be the same, but if thesampling rate is < 2000 Hz, then the precision of results computed
using channel calculations will be less than those using the
Appendix A — Technical Notes

261

computed inputs. This difference affects all corresponding computed
inputs and channel calculations.
2. Computed inputs must use data as they are acquired, whereas
channel calculations are able to use data in a ‘window’ extending
either side of any particular data point. This affects cyclic
computations, because computed inputs must show results for theprevious cycle, whereas the Cycle Variables calculation can show
values for the current cycle. It also affects the Differential computed
input function and channel calculation, because neighboring points
are used in the numerical calculation of a derivative. This is not a
factor for the integral computed functions and the Integral channel
calculation, which do not rely on a window of points.
3. Computed inputs and channel calculations differ in their method ofcycle detection. The former use a threshold and hysteresis function,
while the latter use local maxima or minima. This affects cyclic rateand cyclic amplitude computed input functions and thecorresponding Cycle Variables channel calculation options.
Table C–1
Factors contributing todifferent results fromcomputed inputs andchannel calculations, fordifferent types ofcomputation.

Factors contributing to differences between computed inputs and channel calculations
Computation
type

Sampling rate

Use of ‘window’ data

Cycle detection method

Rate

x

x

x

Cyclicxxx

Differentialxx

Integralx

Reference
1. Press, W.H. et al., Numerical Recipes in C: The Art of Scientific
Computing, second edition (Cambridge University Press,
Cambridge, Massachusetts, 1994).

262

Chart Software

A P P E N D I X

DD Experiments
Gallery
Configuration Files
You can customize the appearance of files that are shown in theExperiments Gallery, by adding text labels, hiding files, choosing adefault selected file, and so on. This is done on a folder-by-folder basis
by adding a configuration file called 'labels.ini' to the appropriate
folder.
The configuration file is a text file containing ‘sections’, ‘key lines’ and(optionally) ‘comment lines’ (see below for an example).
Note: Character case is unimportant for section and key names, but ispreserved in key values.

Sections
A section starts with a line containing a section name in square
brackets, and is followed by key lines. Most section names consist of
filenames (for example, [Electroencephalography] would be the section
name for a Chart data file named ‘Electroencephalography’) and areused to control the appearance of the entry for the file with that name in
the Experiments Gallery dialog box. The order of the filename sectionsin the configuration file is the order the entries are shown in the file list.
Files in a folder that do not have sections in the labels.ini file are shownin the file list after the files that do have entries.
The section name [folder] is optional and is followed with a key line
whose value is text that will be shown in the information area in theExperiments Gallery dialog box. This text is usually used to give a

Chart Software263

general description of a folder. If this section is omitted the info area is
not shown.

Key Lines
A key line contains a key name followed by an equals sign and a key
value. Spaces around the key value are ignored. The following keys
may be used within a filename section:
Text. This key provides the text to be shown as additional description
text for the file.
Flags. Various options used to control some of the behavior andappearance of the entry for a file. Available flags are:• Bold. Show the label (filename and descriptive text) in bold face.
• Default. Make the file selected in the file list whenever the relevant
folder is selected in the Experiments Gallery dialog box.
• MacOnly. Only show this entry on a Macintosh system.
• WinOnly. Only show this entry on a Windows system. (Whencreating labels.ini files that will be used on Windows, you need tocreate them in a text editor that can insert line feed characters.)• Hide. The entry is not shown in the file list.

Comment Lines
A comment line starts with a semicolon (";"). Comment lines may beplaced anywhere in the configuration file and are ignored when Chart
reads the file. Blank lines are ignored and are useful for visually
separating sections.

264

Chart Software

Example
Below is the text of a typical configuration file. The corresponding
appearance of the Experiments Gallery dialog box, when the folder
containing that configuration file is selected, is shown in Figure D–1:
[Folder]
text=A basic experiment on the pulsatile flow of blood, the ECG, andperipheral circulation.
[TLM03c ECG Periph Circ.pdf
text=The instructions for setting up and running this experiment.
flags=default, bold
[TLM03c Data File 1]
text=Typical volume pulse, blood flow, and ECG traces to compare
your data to, or to use in case of poor results.
[TLM03c Data File 2]
text=Typical volume pulse and blood flow to compare your data to, or
to use in case of poor results.
[TLM03c ECG Periph Circ.doc]
text=An editable version of the experiment (in Word format).
[TLM03c Dem Notes.txt]
text=Information for demonstrators about this experiment: answers toquestions and troubleshooting help.

Appendix A — Experiments Gallery Configuration Files

265

Figure D–1
Appearance of the files
in a folder called ECG
Periph Circulation, when
the labels.ini file above
has been added to thefolder.

266

Chart SoftwareIndexA
About Chart dialog box 33, 243

application program
limits 34
versions 253

About Chart… command 33, 243

Apply Calculation… command 170

About this Macintosh dialog box 245

Arithmetic (channel calculation) 40, 173–176

Abs Smoothed (computed input function) 163

Arithmetic dialog box 172

active channel 76

Arithmetic… command 40, 173

active point 98

Auto Comments… command 226

Add Comment dialog box 118

Auto Save… command 108

Add Comment dialog box (Timed Events) 223

Auto Scale Data command 74, 88

Add Comment… command 118

auto scale display 73

Add Exclusion dialog box 118

advanced features 15

automatic comments 226–229
editing 228
events 226–228
numbering 228
repeating 228
saving 228
stimulus frequency 228

aliasing 6–7

Automatic Comments dialog box 227

Amplitude axis 21, 73–75

automatic scrolling 20

Add Exclusion… command 118
Add to Data Pad command 138
adding comments 29
adding data to the Data Pad 138

analysis 15, 129–187
analysis mode 16, 229

automating Chart 16, 202–229

Append dialog box 111

B

Append… command 110, 207background recording 30–31

appending files 110

backup files 126

Apple events 214–215

bandwidth 7, 8, 43

AppleScript 214–215

baseline 132

AppleScript from Macro dialog box 214

baseline tracking 157–158

AppleScript… command 214

basic data acquisition 5–11

Chart Software

267

Begin Repeat command 218

Channel Status pop-up list 22, 27, 167

Begin Repeat dialog box 218

channel titles 81–82

bipolar display 73

Chart Buffer File 199

bipolar output 67

Chart desktop icons 17, 199

Block buttons 20, 26–27

Chart extensions 167, 196–198

Block Information pop-up list 28

Chart for Windows files
opening 18
saving as 107

blocks 26
appended files 110
information 141
internal and user-defined 34
limits 34
lines between 26, 34, 78
navigating 19, 27
recording dates 71
selecting 99, 216, 218Ccalibration 49, 220
Change e-corder Name dialog box 230
changes at fast rates 37, 78
channel calculations 167–187
Arithmetic 173–176
Cycle Variables 176–183
differences with computed input 261
Differential 183–184
Integral 184–187
Smoothing 171
channel controls 21, 38–41
Channel Function pop-up menu 22, 38–41
Apply Calculation… command 170
Arithmetic… command 173
Computed Input… command 153
Cycle Variables… command 177
Differential… command 183
Input Amplifier… command 41
Integral… command 184
No Calculation command 167
Smoothing… command 171
Turn Channel Off command 39
Turn Channel On command 39
Units Conversion… command 46
channel separators 22, 54, 75, 83
Channel Settings dialog box 51, 81
Channel Settings… command 51, 81
Channel Status indicator 22, 41, 167

268

Chart License setup dialog box 4
Chart menu
About Chart… command 33, 243
Quit command 5, 19
Chart window 19–24
printing 113
splitting 71–72
Chart Window command 19
Choose e-corder dialog box 230
Clear Channel… command 100
Clear command 137
Clear Selection command 100
Clipboard 103
Close command 19
closing a Chart file 19
color 54, 82–83, 87
color depth 32, 33, 250, 251
color display 249
Color pop-up menu 22, 38, 72, 79, 87
color printing 112
Commands menu 235
Add Comment… command 118
Add Exclusion… command 118
Add to Data Pad command 138
Auto Scale Data command 74
Find Next command 136
Find… command 133
Remove Baseline command 132
Set Baseline command 132
comments 29, 117–124
adding after recording 118
adding while recording 29, 226
automatic 226–229
boxes 29, 80, 119channel-specific 29, 117, 119deleting 122
Chart Softwareediting 122
finding 122, 134
identifying data points 123, 132
including in text file 103
lines and areas 80
numbering 110, 119, 122
printing 123, 252reading 29
show/hide 80
specific 29, 117, 119
text labels 80, 119
truncation 123

Copy command 100, 101, 102, 137
Copy to Clipboard dialog box 102
Counter (computed input function) 162
CPU load 23, 25, 31
crashes 253
Cursor… command 192
customer comment 246
customizing Chart 16, 189–231
Cut command 137

Comments & Exclusions window 121

Cycle Variables (channel calculation) 40, 176–183
Data Pad functions 183
functions 180–181

comments bar 25

Cycle Variables… command 40, 177

computed input 40, 53, 153–167
controls 158–159
differences with channel calculations 261
functions 159–167
raw data controls 155–157
sampling rates 154

Cyclic Height (computed input function) 163

Computed Input dialog box 153

D

computed input function
Abs Smoothed 163
Counter 162
Cyclic Height 163
Cyclic Max 163
Cyclic Mean 162
Cyclic Min 163
Differential 165
Envelope Max 164
Envelope Min 164
Frequency 161
Integral 165–167
1/3Max+2/3Min 163
Period 160–161
Ratemeter 159
RMS Smoothed 163

data acquisition 5–11

Comments & Exclusions command 121

Cyclic Max (computed input function) 163
Cyclic Mean (computed input function) 162
Cyclic Min (computed input function) 163

data buffering 198–200
Data Buffering… command 199
data compression 33
data display area 22, 39, 75
channel areas 75
splitting 71–72, 85
Data display bar 26
data file 105
data limit area 157
data loss 6, 32, 100, 127, 155, 170, 199, 208,
251, 253

Controls… command 194

Data Pad 101, 108, 136–145
adding data 89, 138different block units 138
functions 139–144
limits 136
printing 114, 145
saving as text file 108
setting up 138–144
Spectrum functions 143

conventions 2

Data Pad Column Setup dialog box 139

Copy as Picture dialog box 101

Data Pad command 137

Computed Input… command 153
computer requirements 3
contacting eDAQ ii, 244
controls and display 14
Controls dialog box 194, 200

Index

269

Data Pad Value miniwindow 143

e-corder Startup… command 229

data resolution 38, 75

e-corder system 3

DC output voltage 67

e-corder Unavailable dialog box 4

dealer and distributor information 244

eDAQ contacts ii, 244

default settings 17, 200eDAQ Contacts dialog box 244

Define Unit Name dialog box 50

Edit menu 234
Clear Channel… command 100
Clear command 137
Clear Selection command 100
Copy command 100, 101, 102, 137
Cut command 137
Paste command 137
Select All command 99
Show Clipboard command 103

defining units 50
Delete Macro dialog box 205
Delete Macro… command 204
Delete Unit Name dialog box 50
deleting units 50
dialog box placement 249
different sampling rates by channel 52
differential
signal input 44
time derivative 165
Differential (channel calculation) 40, 183–184

emergency access 201–202
End Repeat command 218
Envelope Max (computed input function) 164
Envelope Min (computed input function) 164

Differential (computed input function) 165

exclusion uses 123–124

Differential… command 40, 183

exclusions — see comments

digital filters 43
digital read-outs 89–93
digital voltmeter 89
digitization 9
discontinuity 26, 78, 87, 100, 141, 146
display and expectations 11
display at fast rates 37, 78
display offset 44
display settings 11, 77–80
Display Settings dialog box 77

Experiments Gallery 17, 19, 96–98
configuration files 263–265
Experiments Gallery command 96
extensions 167, 196–198
Extensions Manager dialog box 197
Extensions… command 197
external devices
responding to 227–229
external trigger marker 59
External Trigger Options dialog box 190
External Trigger… command 190

Display Settings… command 77
divisions 36
DVM 89–93
DVM Log window 108
saving as text file 108
DVM miniwindow 90
DVM submenu 89

F
Fast Fourier Transform 147, 257–261
fast tracking 157
faster printing 252
FFT 147, 257–261
File Information dialog box 125

E

File Information… command 124

e-corder Settings 50

File menu 234
Append… command 110, 207
Close command 19

e-corder Startup dialog box 229

270

Chart Software

Experiments Gallery command 96
File Information… command 124
Find File… command 125
New command 17
Open… command 17, 207
Page Setup… command 111
Print… command 111
Save As… command 101, 104–108, 208
Save command 104
Save Selection… command 100, 109, 208
file problems 253
file types
buffer 200
data 105
settings 105
text 106
filtering 7–8, 43–44
AC coupled 43
basics 7–8
digital 43
high-pass (baseline tracking) 157
low-pass 43
mains 43H
high-resolution printing 112
horizontal compression 21, 37
hysteresis 156

Iinitial display 38
input amplifier 40, 41–45, 53
Input Amplifier dialog box 42
Input Amplifier… command 41
IntegralAbsolute Value 166
Negative Only 166
normal 165
Positive Only 166
Reset Each Cycle 166
resetting 159, 166
Time Constant 167
Timed Reset 167
Integral (channel calculation) 40, 184–187

Find and Select dialog box 133

Integral (computed input function) 165–167

Find File dialog box 125

Integral… command 40, 184

Find File… command 125

interference 11

Find Next command 136

internal timer 56–57, 59

Find… command 133

introduction to data acquisition 5–11

finding Chart files 124–126
finding comments 122, 134K

finding data 134

keyboard shortcuts 19, 194, 237
changing 194
conventions 2
macros 204

finding events 133–136
First Point command 131
Found Files dialog box 126
Frequency (computed input function) 161
frequency range 7
Function keys 24, 192, 227

L
Last Point command 131
License Manager… command 196

Gglitches 123

licensesadding 196
deleting 196
entering new Chart 4

graticule 36, 37, 79

licensing your copy of Chart 3

general display controls 77–80

limits of files 34

Index

271

lines between blocks 26, 34, 78

timed events 225, 229
user changes to settings 206
versions 202

locating events 84, 89
low-pass filters 43

Mmacro commands 209–221
Macro Commands submenu 236AppleScript… command 214
Begin Repeat command 218
End Repeat command 218
Message… command 212
Play Sound… command 211
Repeat Select Each Block command 218
Repeat Select Every… command 216
Repeat While in Block command 216
Set Units Conversion… command 219
Speak Message… command 213
Stop Sampling command 221
Update Screen command 209
Wait While Sampling command 221
Wait… command 210
Macro menu 236
Delete Macro… command 204
Start Recording command 203

mains filter 43
Marker 23, 87, 123, 131–132
marker channel (for stimulus) 63
Maximum Point command 131
measurement
direct 130
relative 131
Memory Cache… command 198
memory indicator 23
memory indicators 26
menu commands
conventions 2
hiding 193
locking 193
menus 233–236
altering 192–194
and the Tool bar 193
creating 203
hiding 193
Menus dialog box 193

Macro Message dialog box 212

Menus… command 192

Macro Play Sound dialog box 212

Message… command 212

Macro Sampling dialog box 206

Minimum Point command 131

Macro Wait dialog box 210

monitoring 27

macros 202–221
appending files 207
called by other macros 209
changing dialog box settings 205–206
commands 209–221
deleting 204–205
discarding when opening files 202
keeping records 202
keyboard shortcuts 204
loading 202
nesting 209, 218
opening files 207
playing 204
recording 203–204
sampling 206
saving 203–204
saving files 208–209
stopping 204

272

Nnaming an e-corder 230
navigating 19
New command 17
No Calculation command 167
noise 10Notebook 115–116
printing 116
Notebook command 115
Notebook window 116
number of channels appearing 38, 54
number of channels on 38
Nyquist frequency 6

Chart SoftwareOe-corder Startup… command 229
Extensions… command 197
External Trigger… command 190
License Manager… command 196
Memory Cache… command 198
Menus… command 192
Startup… command 200
Tool Bar… command 190

off-screen buffer 33, 251
1/3Max+2/3Min (computed input function) 163
Open dialog box 17
Open File for Macro dialog box 207
Open… command 17, 207
opening a Chart file 16

pre-triggering 57

Output Voltage… command 66

Print dialog box 113

overlaying channels 76–77, 83

Print… command 111

overlaying in Zoom window 86

Paste command 137

printing 111–115
Chart window 113
color 112
commands 113
comments 123
Data Pad 145
faster 252
high-resolution 112
Notebook 116
problems 252
restricting 195
Spectrum window 113
X–Y window 146
Zoom window 89

performance 31–32

problems and solutions 246–254

Period (computed input function) 160–161

Pulse stimulus waveform 62

Overview command 84
Overview miniwindow 84–85, 133
overview of Chart 14–16

P
Page Layout dialog box 114
page setup 111–113
Page Setup dialog box 112
Page Setup… command 111

Play Sound… command 211
pointer 24
arrow-headed cross 191
cross 130
double-headed arrow 99, 130
dragging 74
hand 20, 88
heavy cross 137
I-beam 24, 137
resizing 122, 138
separator 75
split 71
stretching 74

Qpost-triggering 57

Range/Amplitude display 22, 25, 39, 130, 132preferences 190–196
preferences file 50
Preferences submenu 234
Controls… command 194
Cursor… command 192
Data Buffering… command 199

Index

Quit command 5, 19
quitting Chart 5, 19

R
Ramp stimulus waveform 62
range 9–10, 38, 44, 53, 155, 158
basics 9–10
choosing 38
Range pop-up menu 22, 38, 158
Rate pop-up menu 22, 36, 52
Rate/Time display 22, 26, 36, 52, 130, 132
Ratemeter (computed input function) 159
raw data 53, 155, 158
Record/Monitor button 23, 27273

hiding 195

Save Selection… command 100, 109, 208

recording 14, 25–34
changing settings during 26, 31
different sampling rates by channel 52
fidelity 11, 75
limits 32
media 127, 199
problems 249–251
resolution 10, 38, 75
running other applications 31
split data display 30–31
to disk 34
to RAM 33
while reviewing data 30

saving a selection 109

Recording Status indicator 25, 28

Select All command 99

recovering files 127, 253

selecting data 99–100

reduction 103

selection information 140

Remove Baseline command 132

sensitivity bandwidth 156

Repeat Select Each Block command 218

Set Baseline command 132

Repeat Select Every dialog box 217

Repeat While in Block command 216

Set Marker submenu 235
First Point command 131
Last Point command 131
Maximum Point command 131
Minimum Point command 131

RMS Smoothed (computed input function) 163

Set Scale dialog box 73

Repeat Select Every… command 216
repeat sequence 224

Ssampling rates 6–7, 36
and View buttons 36
appropriate 6–7
basics 6–7
computed input 154
continuous 37, 52
different by channel 52
digital filters 32, 43
mains filter 43
problems 249
slow 37
too low 6
Save As dialog box 104
Save As Text File dialog box 106
Save As… command 101, 104–108, 208

scalemoving 74
setting 74
stretching 74
Scale pop-up menu 21, 73, 76
Scaling buttons 21, 74
Scroll bar 19
scroll while sampling 78
Scroll/Review button 24, 30, 195
scrolling speed 36

Set Scale… option 73
Set Units Conversion dialog box 219
Set Units Conversion… command 219
settings 18, 103, 105, 200
settings file 105
Setup menu 235
Auto Comments… command 226
Channel Settings… command 51, 81
Display Settings… command 77
Output Voltage… command 66
Stimulator command 60
Stimulator Panel command 65
Timed Events… command 222
Trigger command 55
Zero All Inputs command 46
shortcuts 237–241
Show Clipboard command 103

Save command 104

signal conditioning 5

Save File for Macro dialog box 208

signal input controls 44

Save Selection directory dialog box 110

Sine stimulus waveform 62

274

Chart Softwaresingle-sided display 73

Stimulator window 61

slope 141

stimulus marker 63

Slow Sampling submenu 37

Smoothing dialog box 171

stimulus waveform
Pulse 62
Ramp 62
Sine 62
Step 62
Triangle 62

Smoothing… command 40, 171

Stop Sampling command 221

Speak Message dialog box 213

superscripts and subscripts 50, 82, 137

Speak Message… command 213

system configuration information 244–245

slow tracking 157
smoothing 171–173
Smoothing (channel calculation) 40, 171

special access 201–202
Special Access dialog box 201

T

specifying connections 229–230

tear-off data displays 89, 145

Spectrum command 147

technical support 243–246

Spectrum window 108, 147–152
calculation details 257–261
printing 113
saving as text file 108
settings 149–152
Split bar 23, 30, 71–72
stacking in Zoom window 86

text file 106
threshold and sensitivity 156
Time & Date button 24, 70
time and date display 71
Time axis 21
problems 247

Start button, Chart window 23

time display mode 21, 26

Start Recording command 203

Time Format & Display dialog box 70

startup problems 246–247

time scale controls 70–71, 78

Startup Settings dialog box 200

Timed Event Stimulator Output dialog box 224

Startup… command 200
state changes 226
statistics 139
Step stimulus waveform 62
stimulation 60–67, 228
automatic comments 228
changing during sampling 66
continuous 62
discrete 63
mode 61

timed events 222–226
accuracy 225
actions 223–224
Analog Output 2 223
editing 224
macros 225, 229
saving 224
turning off 224
Timed Events dialog box 222
Timed Events… command 222

Stimulator command 60

Tool bar 24, 190–192, 205
and automatic comments 192, 227
and menus 193

Stimulator Constant Output dialog box 66

Tool Bar Settings dialog box 191

Stimulator output 67

Tool Bar… command 190

Stimulator Panel command 65

transferring data 101–103

Stimulator Panel miniwindow 65

Triangle stimulus waveform 62

Stimulator 60–67

Index

275

Trigger command 55

warning icon 170

Trigger Marker 60

Waveform Cursor 87, 130, 131, 192

Trigger window 55

Waveform Cursor dialog box 192

triggering 55–60, 227
automatic comments 227
changing in Chart window 59
external 56, 59, 227
external modes 190
fixed duration 58
level 57
slope 57
source 56
synchronizing recording 231
threshold 56, 227

waveforms
stacking 86
superimposing 85

triggering event 56
Turn Channel Off command 39
Turn Channel On command 39
turning channels off and on 38–39, 75

U
underlying data 170
units conversion 40, 45, 46–50, 53, 73, 99
calibration 49
Data Pad calculations 138
prefixes 248
typing in values 48
using sampled data 48–49
Units Conversion dialog box 46
Units Conversion… command 46
Update Screen command 209
using this guide 2

where to start 2
window
Chart 19–24
Comments & Exclusions 121
Data Pad 136–145
Notebook 116
Spectrum 147–152
Stimulator 61
Trigger 55
X–Y 101, 145–146
Zoom 85–89, 101
Window menu 236
Chart Window command 19
Comments & Exclusions command 121
Data Pad command 137
DVM command 89
DVM Log Window command 92
Notebook command 115
Overview command 84
Spectrum command 147
X–Y Window command 145
Zoom Window command 85

X
X–Y plot 79
X–Y window 101, 145–146
printing 146

V

X–Y Window command 145

versions 253

Z

View buttons 21, 84, 113
and sampling rates 36

Zero All Inputs command 46

Voltage at Input dialog box 44

Zoom window 85–89, 101

voltmeter 45

Zoom Window command 85

W
Wait While Sampling command 221
Wait… command 210

276

Chart Software

Licensing & Warranty

Copyright and Trademarks
e-corder and PowerChrom are registeredtrademarks, and EChem a trademark of eDAQ Pty
Ltd. Chart and Scope are trademarks of
ADInstruments Pty Ltd and are used under license.
All eDAQ software, hardware, and documentation
is protected by copyright. eDAQ retains the
exclusive ownership of the trademarks andregistered trademarks represented by its company
name, logo, and product names.

Responsibilities
You and any others using any eDAQ product agree
to use it in a sensible manner for purposes for which
it is suited, and agree to take responsibility for theiractions and the results of their actions.
If problems arise with an eDAQ product, eDAQ will
make all reasonable efforts to fix them. This service
may incur a charge, depending on the nature of the
problems, and is subject to the other conditions inthis Agreement.

Hardware Warranty
eDAQ Pty Ltd warrants e-corder systems, to be freeof defects in material and workmanship for one year
from the date of purchase. eDAQ Pty Ltd will repair
or replace defective equipment as appropriate.

Chart Software

To obtain a warranty repair/replacement you mustfirst notify us before return of the instrument and wewill issue you with a RAN (return authorization
number). You must ship the defective product at yourexpense. We will pay return shipping. The productshould be packed safely (preferably in its original
packaging) and have the RAN on the shippinglabel. Returns sent without a RAN may be refuseddelivery.
This warranty does not cover hardware that has:• been modified by the user in any way;
• been subjected to unusual physical, electrical,
or environmental stress. This includes damage
due to faulty power sockets, inadequate
earthing, or power spikes or surges;• been damaged because of incorrect wiring toancillary equipment, or because of substandard,connectors or cables; or• had the original identification marks removed
or altered.

Software License
You have the non-exclusive right to use the supplied
Scope software. (Your employees or students, forexample, are entitled to use it, provided they adhere
to this agreement.) Each separate purchase of the
Scope software licenses it to be used on two
computers at any given time (on one computer fordata acquisition with an e-corder hardware unit,277

and on a second computer for the analysis ofexisting data files). Although multiple copies of aprogram may exist on several computers, more than
two copies must not be used simultaneously.
Departmental/company licences are available if you
wish to run more than two copies simultaneously.

Technical Support
Please register your unit to receive technical support.
Technical assistance is available via email. Please
describe the problem with as much detail as
possible. Include a small example data file, if
appropriate. Please also state:• the model and serial number of your e-corderunit.
• the type of computer and operating systembeing used (for example Windows XP, or
Macintosh OS 10.2)• the software version you are using (forexample Scope v4.0.1)
We endeavor to answer all your questions, but insome cases, for example where the problem relates
to the other equipment that you are using, a nominal
fee may be charged.

Jurisdiction
eDAQ Pty Ltd is bound by the laws of New South
Wales in Australia, and any proceedings shall beheard by the Supreme Court of New South Wales inAustralia.

Disclaimer
eDAQ reserves the right to alter specifications ofhardware and software without notice.
No liability can be accepted for consequential
damages resulting from use of eDAQ products.

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Chart Software