CIO-EXP16
Analog Multiplexer board
User's Guide

Document Revision 1A, January, 2007
© Copyright 2007, Measurement Computing Corporation

Trademark and Copyright Information
Measurement Computing Corporation, InstaCal, Universal Library, and the Measurement Computing logo areeither trademarks or registered trademarks of Measurement Computing Corporation. Refer to the Copyrights &Trademarks section on mccdaq.com/legal for more information about Measurement Computing trademarks.
Other product and company names mentioned herein are trademarks or trade names of their respective
companies.
© 2006 Measurement Computing Corporation. All rights reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted, in any form by any means, electronic, mechanical, by
photocopying, recording, or otherwise without the prior written permission of Measurement Computing
Corporation.
NoticeMeasurement Computing Corporation does not authorize any Measurement Computing Corporation product for
use in life support systems and/or devices without prior written consent from Measurement Computing
Corporation. Life support devices/systems are devices or systems that, a) are intended for surgical implantation
into the body, or b) support or sustain life and whose failure to perform can be reasonably expected to result ininjury. Measurement Computing Corporation products are not designed with the components required, and are
not subject to the testing required to ensure a level of reliability suitable for the treatment and diagnosis ofpeople.

HM CIO-EXP16.doc

3

4

Table of Contents
Preface

About this User’s Guide .......................................................................................................................7
What you will learn from this user’s guide.........................................................................................................7
Conventions in this user’s guide.........................................................................................................................7
Where to find more information .........................................................................................................................7
Chapter 1

Introducing the CIO-EXP16 ..................................................................................................................8
Overview: CIO-EXP16 features .........................................................................................................................8
Software features ................................................................................................................................................8
Chapter 2

Installing the CIO-EXP16 ......................................................................................................................9
What comes with your CIO-EXP16 shipment? ..................................................................................................9
Hardware .......................................................................................................................................................................... 9
Optional components ........................................................................................................................................................ 9
Additional documentation................................................................................................................................................. 9

Unpacking the CIO-EXP16 ..............................................................................................................................10
Connecting to the A/D board............................................................................................................................10Signal cable......................................................................................................................................................................10
Cabling.............................................................................................................................................................................11

Configuring the CIO-EXP16 ............................................................................................................................12
Power source....................................................................................................................................................................13
A/D board type ................................................................................................................................................................15
A/D Channel for EXP Output ..........................................................................................................................................15
EXP Gain .........................................................................................................................................................................16
Solder gap switches .........................................................................................................................................................16

Configuring the A/D board...............................................................................................................................17
Single-ended mode ..........................................................................................................................................................17
Range ...............................................................................................................................................................................17
Polarity.............................................................................................................................................................................17

Calibrating the CIO-EXP16..............................................................................................................................17
Chapter 3

Functional Details ...............................................................................................................................18
CIO-EXP16 inputs............................................................................................................................................18
Connecting to a signal source ..........................................................................................................................................18

Thermocouples .................................................................................................................................................19
Cold junction compensation.............................................................................................................................................20
Open thermocouple detect ...............................................................................................................................................20
Low pass filter .................................................................................................................................................................20
Ground reference .............................................................................................................................................................20
Input impedance...............................................................................................................................................................20

Amplification and thermocouples.....................................................................................................................20
Chapter 4

Programming and Developing Applications ....................................................................................22
Programming languages ...................................................................................................................................22
Packaged applications programs.......................................................................................................................22
Chapter 5

Specifications......................................................................................................................................23
Analog input .....................................................................................................................................................23
Cold junction compensation .............................................................................................................................23
Analog output ...................................................................................................................................................24
5

CIO-EXP16 User's Guide

Digital input......................................................................................................................................................24
Power consumption ..........................................................................................................................................24
Environmental ..................................................................................................................................................24
Main connector and pin out ..............................................................................................................................25

6

Preface

About this User’s Guide
What you will learn from this user's guideThis user's guide describes the Measurement Computing CIO-EXP16 data acquisition board andlists hardware specifications.

Conventions in this user's guide
For more information
Text presented in a box signifies additional information related to the subject matter.
Caution! Shaded caution statements present information to help you avoid injuring yourself and others,
damaging your hardware, or losing your data.
bold text

Bold text is used for the names of objects on a screen, such as buttons, text boxes, and check boxes.

italic text

Italic text is used for the names of manuals and help topic titles, and to emphasize a word or phrase.

Where to find more information
Additional information about CIO-EXP16 hardware is available on our website atwww.mccdaq.com. You can also contact Measurement Computing Corporation with specific questions.


Knowledgebase: kb.mccdaq.com
Tech support form: www.mccdaq.com/support/support_form.aspx
Email: techsupport@mccdaq.com
Phone: 508-946-5100 and follow the instructions for reaching Tech Support

For international customers, contact your local distributor. Refer to the International Distributors section on our
website at www.mccdaq.com/International.

7

Chapter 1

Introducing the CIO-EXP16
Overview: CIO-EXP16 features
The CIO-EXP16 is a 16-channel signal conditioning accessory board supported under popular Microsoft®
Windows® operating systems.
The CIO-EXP16 is used to expand the number of analog inputs and the range of amplification of DAS08 and
DAS16 series boards. Using multiple CIO-EXP16 boards, a 16 channel A/D board can be expanded to up to
256 inputs; an 8 channel A/D board can be expanded to up to 128 inputs.
The CIO-EXP16 board has 16 differential inputs that are multiplexed into one single-ended output channel.
Four digital inputs are controlled by the A/D board's digital outputs, and are used to select one of themultiplexed channels for output. An on-board semiconductor sensor provides a cold junction compensation(CJC) reference for thermocouple applications.
You select one channel on the A/D board to send the multiplexed analog output to. In addition, you can output
the CJC signal to a second A/D board channel. You can enable an input filter, ground reference, and open
thermocouple detect options for each channel using on-board solder gap switches. You specify the gain of themultiplexer with an onboard gain switch.
You can power the CIO-EXP16 internally from the A/D board, or externally from the computer's +5 V power
supply connectors.
The CIO-EXP16 board is mounted externally to the PC. It can be placed in the open on a benchtop or in a case.

Software features
For information on the features of InstaCal and the other software included with your CIO-EXP16, refer to the
Quick Start Guide that shipped with your device. The Quick Start Guide is also available in PDF at
www.mccdaq.com/PDFs/manuals/DAQ-Software-Quick-Start.pdf.
Check www.mccdaq.com/download.htm for the latest software version.

8

Chapter 2

Installing the CIO-EXP16
What comes with your CIO-EXP16 shipment?
The following items are shipped with the CIO-EXP16.

Hardware

CIO-EXP16

Optional components
You can also order the following MCC products to use with your CIO-EXP16.

C37FF-x

C-EXP2DAS16-10

C-PCPOWER-10

BP-POWER

Additional documentation
In addition to this hardware user's guide, you should also receive the Quick Start Guide (available in PDF at
www.mccdaq.com/PDFs/manuals/DAQ-Software-Quick-Start.pdf). This booklet supplies a brief descriptionof the software you received with your CIO-EXP16 and information regarding installation of that software.
Please read this booklet completely before installing any software or hardware.

9

CIO-EXP16 User's Guide

Installing the CIO-EXP16

Unpacking the CIO-EXP16
As with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the CIO-EXP16 from its packaging, ground yourself using a wrist strap or bysimply touching the computer chassis or other grounded object to eliminate any stored static charge.
If any components are missing or damaged, notify Measurement Computing Corporation immediately byphone, fax, or e-mail:

Phone: 508-946-5100 and follow the instructions for reaching Tech Support.
Fax: 508-946-9500 to the attention of Tech Support
Email: techsupport@mccdaq.com

Connecting to the A/D board
There are two 37-pin D type connectors on the CIO-EXP16 — P1 and P2. They are wired 1:1. Connector P1 islabeled NEXT EXP, and is provided to daisy chain additional CIO-EXP16 boards. Use a C37FF-x cable to daisy
chain the CIO-EXP16 boards together. Do not exceed 50 feet in length.
Signals may be connected from the CIO-EXP16 board to the A/D board through one of two types of cables. The
cable used depends upon the type of A/D board you are connecting to. The table below lists the CIO-EXP16
board's connectors and compatible cables.
Board connector, cables, and accessory equipment
Connector typeCompatible cables with connector P1
Compatible cables with connector P2

P1 and P2: 37-pin D type connector
C37FF-x (connecting to additional CIO-EXP16 boards)
 C37FF-x (connecting to a DAS08 board) C-EXP2DAS16-10 (connecting to a DAS16 board)

Signal cable
The CIO-EXP16 signal connector is nearly a mirror of the CIO-DAS08 signal cable.

NC / LLGND
LLGND / Output
Output 9
Output 10
Output 11
Output 12
Output 13
Output 14
Output 15
MUX Addr 4
MUX Addr 3
MUX Addr 2
MUX Addr 1
NC
NC
NC
NC
NC
+12V PC Bus

19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1

37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20

Figure 1. Connector P2/P1

10

Output 0
Output 1
Output 2
Output 3
Output 4
Output 5
Output 6
Output 7+5V
Power GND
NC
NC
NC
NC
NC
NC
NC
-12V PC Bus

CIO-EXP16 User's Guide

Installing the CIO-EXP16

Cabling

37

37

19

The red stripe
identifies pin # 1
20

20

19

1

1

Figure 2. C37FF-x cable

Connecting to a DAS08 Series board
Leave the A/D BOARD TYPE jumper in the default DAS08 position. Use a C37FF-x cable to connect to DAS08
series boards.
Connecting to a DAS16 Series A/D Board
Set the A/D BOARD TYPE jumper to the DAS16 position.
Connection to a DAS16 series board requires a special 37-conductor cable (C-EXP2DAS16-10) since the pin
relationship of the CIO-EXP16 and DAS16 signals is not 1:1. Refer to the C-EXP2DAS16-10 cable pin out
table below.
C-EXP2DAS16-10 cable pin out
P1 (MUX)

P2

7
8
9
10
11
12
13
14
15
16
17
18
19
28
29
30
31
32
33
34
35
36
37
N/C

23
4
22
3
11
12
13
14
15
16
17
18
19
7
1
30
31
32
33
34
35
36
37
Shell Shield11

CIO-EXP16 User's Guide

Installing the CIO-EXP16

Information on signal connections
General information regarding signal connection and configuration is available in the Guide to
Signal Connections (available at www.mccdaq.com/pdfs/DAQ-Signal-Connections.pdf).

Configuring the CIO-EXP16
Before using the CIO-EXP16, there are switches and jumpers to set, and one or more cables to install. Pleaseturn the PC power OFF before proceeding. The CIO-EXP16 is shipped with the factory-default settings listed in
the following table.
Factory-configured default settings
Jumper/switch

Description

Default setting

Power source select switch
S3
A/D BOARD TYPE jumper
EXP OUTPUT TO DAS
jumper+5V power switch that sets the power source tointernal or external

INT (internal +5V PC power)

Selects DAS08 or DAS16 compatibility
Selects the A/D board channel to connect themultiplexed analog output to.

CJC OUTPUT TO DAS
jumper

Selects the A/D board channel to connect the
CJC output to.

GAIN switches
S1
V, C and G solder bridge
switches (one for each input
channel)Four DIP switches that set the gain of thedifferential amplifier.

DAS08
0(EXP multiplexed output connects tochannel 0 on the A/D board)
7(CJC circuit connects to channel 7 on
the A/D board)
Gain = 1 (all gain switches OFF)Three 'connect pads' per channel on the etchside (under side) of the CIO-EXP16 board.
Bridge each pad to configures its associatedinput channel as follows: Bridge the V pads to enable open
thermocouple detection for the associatedinput channel.
 Bridge the C pads to connect a 1 µF
capacitor across the signal high and low
inputs, forming a low-pass filter having a 7
Hz cutoff.
 Bridge the G pads to enable a reference toground for the associated input channel.

12Open pads (all are not bridged)

CIO-EXP16 User's Guide

Installing the CIO-EXP16

Figure 3 shows the location of the board jumpers, switches, and connectors. The solder bridges are on the underside of the board, and are not shown in the figure.
EXP and CJC Output to
DAS channel jumpers

A/D Board TypejumperPowersourceswitchS3

Gainswitches
S1

External power
connector
P15

Figure 3. Switch, jumper, and connector locations

Before using the CIO-EXP16, verify that the board is configured with the settings that you want. Review thefollowing information to change the default configuration of a jumper, switch, or solder gap.

Power source
You can supply +5V DC power to the via the 37-conductor cable from the A/D board in the PC (internal), or via
a separate optional power cable connected directly to the PC power supply (external). The internal method isadequate for powering up to five CIO-EXP16 boards. Supply external power (connect the C-PCPOWER-10
power cable) when:More than five CIO-EXP16 boards are used with one A/D board.
The A/D board in use does not supply +5V to its connector

Configure the CIO-EXP16 board’s power source with switch S3 for either internal or external power. Figure 4
shows this switch configured in both positions.

+5

EXT

S3

+5

INT

EXT

S3

INT

Internal power

External power+5V power from thePC via 37 conductor
signal cable+5V power from thePC via 2 conductor
optional C-PCPOWER-10
power cable

Figure 4. Power source-select switch

13

CIO-EXP16 User's Guide

Installing the CIO-EXP16

External +5 V PC power connections
You can power the CIO-EXP16 with your computer’s +5V power supply using the optional C-PCPOWER-10
cord. Each end of the cable has a keyed Molex® type connector. To connect to your computer’s power
connectors, do the following:
1.

Turn off power to the computer and remove the cover.

2.

Connect the black cable with the white Molex® type connectors to one of the unused PC expansion power
connectors from the PC power supply. They are keyed, so the cable will plug into the expansion connector
easily when they are aligned (see Figure 5).
Personal Computer

Power cable
J3 to PC Power Supply

Signal cableP2 to CIO-DAS08
analog board
DC/DC

CIO-EXP16

Figure 5. External power cable installation

3.

Run the power cable out the back of the computer through an expansion slot or other opening and replace
the cover on the computer.
You can alternatively connect the C-PCPOWER-10 to a BP-POWER adaptor to bring PC power out of thecomputer. This adaptor provides three standard power connectors mounted on a backplate. Details on this productare available on our web site at www.mccdaq.com/products/accessories.aspx.

Caution!

Be careful not to pinch the cable when you replace the cover—if this cable is cut, the resulting shortcircuit can damage the computer.

4.

Connect the other end of the power cord to the connector labeled "OPTIONAL EXTERNAL +5V POWER"(P15) on the CIO-EXP16. This end is keyed also. Refer to Figure 3 for the location of this connector.

5.

Slide the power source select switch (S3) to the EXT position.

14

CIO-EXP16 User's Guide

Installing the CIO-EXP16

A/D board type
Use the 4-pin jumper labeled A/D BOARD TYPE to configure the CIO-EXP16 for use with the DAS08 familyof boards or the DAS16 family of boards. Place the jumper in the position for the type of A/D board you areusing with the CIO-EXP16. Figure 6 shows the jumper configured with its default setting of DAS08.

LLGND
DAS08

DAS16
P2, pin19
P2, pin 18
Figure 6. Board type select jumper

A/D Channel for EXP Output
Select a separate A/D channel for each CIO-EXP16 output that you plan to use. Each CIO-EXP16 has two
potential signals — the output of the 16 multiplexed inputs, and the output of the CJC circuit. The output of the
CIO-EXP16 selected channel is an input to the A/D board.
Two rows of 16 jumper pairs located near the 37-pin connectors are labeled with A/D board channel numbers(see Figure 7). These channel numbers designate which of the A/D board's input channels will be connected to
the MUX board’s output(s). Each CIO-EXP16 output, if used, must be exclusively assigned to an A/D channel
using these jumpers. In other words, for all CIO-EXP16 boards attached to an A/D board, only one jumper on
any of the jumper blocks should be assigned to a particular channel.
Figure 7 shows the layout of the jumper blocks on the CIO-EXP16.
EXP OUTPUT TO DAS

0 1 2 3 4 5 6 7

8 9 10 11 12 13 14 15These jumpers are forboards with 16 channels
only, such as the CIO-DAS16
in 16 channel mode.

CJC OUTPUT TO DASDAS8/16
DAS16 ONLY

Figure 7. EXP Channel Select and CJC Select jumper blocks

The CIO-EXP16 has 16 input channels multiplexed into one output. This output is connected to the jumper
block labeled EXP OUTPUT TO DAS. This jumper block determines which analog input channel of the A/D
board in the computer is connected to the output from the CIO-EXP16 board.
The CIO-EXP16 also has a semiconductor temperature sensor on board to measure the temperature of the board
in the region of the screw terminals. The temperature at the screw terminals is needed when thermocouples areused with the CIO-EXP16. The temperature at the screw terminals is called the Cold Junction temperature, andis needed to accurately calculate thermocouple temperature. This is known as Cold Junction Compensation.
When a CIO-EXP16 channel is used with a thermocouple, install the CJC OUTPUT TO DAS jumper in thedesired channel location. If you are not using thermocouples, do not install it.


Select the A/D board channel to connect the multiplexed analog output to using the jumpers labeled EXP
OUTPUT TO DAS.
Channels 0-15 are connected by default to A/D board channel 0.
Select the A/D board channel to connect the CJC output to (if required) using the jumpers labeled CJC
OUTPUT TO DAS.
CIO-EXP CJC is connected by default to A/D channel 7.

15

CIO-EXP16 User's Guide

Installing the CIO-EXP16

Channel selection for the DAS08 family
The DAS08 family of boards has eight channels of input, so only CIO-EXP16 jumper positions 0-7 are valid.
Many boards in the DAS08 family of boards have single-ended inputs, which is the correct type to connect to a
CIO-EXP16. If the inputs on the board type you are using are differential, they must be converted to singleended inputs (refer to the hardware user's manual supplied with your A/D board for more information).
You can connect up to eight banks of 16 CIO-EXP16 inputs to a DAS08 series board, for a total of 128 inputs.
Channel selection for the DAS16 family
The CIO-EXP16 jumper positions 0-7 and 8-15 can be used with the CIO-DAS16. You can connect up to 16
banks of 16 CIO-EXP16 inputs to a DAS16 series board, for a total of 256 inputs.
Most of the DAS16 family of A/D is switch-selectable for either 8 differential or 16 single-ended channels. Set
the switch for 16-channel, single-ended mode.

EXP Gain
The CIO-EXP16 has a bank of four DIP switches that control the gain of the differential amplifier (Figure 8).

S1
x500

4

x200

3

x100

2

x10

1
ON = left

Figure 8. Gain switch

The gain associated with a switch is 'ON' when the switch is to the left, and 'OFF' when the switch is to theright. The gains are additive, so a total of 16 different gains are possible. The board is shipped with all switches
off (gain =1). The switch shown in Figure 8 is configured for a gain of 700 (500 + 200).
For most thermocouple applications, the gain should be set to at least 100. Refer to the section Amplificationand thermocouples on page 20 for data on setting optimum amplifier gains when using thermocouples.
For most other applications, the gain should be set to result in output signal levels as close to ±5V or ±10V
(depending on the range setting on the A/D board) as possible.

Solder gap switches
Each analog input channel on the CIO-EXP16 has three dedicated solder gap switches labeled C, V, and G on
the circuit side (under side) of the board. Each solder gap switch enables a different thermocouple option. A
typical set of solder gap switches is shown here.

VCG
Figure 9. Solder gap switches (typical per channel)

A solder gap switch has two pads. Turn on each switch by soldering the pads together to close them — this iscalled a solder bridge. When closed, or bridged, the pads connect resistors and capacitors to the input signals
and enable the following options:Open thermocouple detect (V pad) — enables open thermocouple detection to alert you if athermocouple breaks. Note that your software program must be designed to recognize when a negative
full-scale condition exists, since the input is pulled to minus full-scale if the thermocouple wire isbroken or disconnected.



Input filter (C pad) — connects a 1 µF capacitor across the signal high and low inputs. This forms a
7 Hz low pass filter that filters out signal noise that is picked up on the thermocouple wire.
16

CIO-EXP16 User's GuideInstalling the CIO-EXP16

Input ground reference (G pad) — provides a reference to ground through a 100 k resistor. Thisreference prohibits floating thermocouple readings.

You should bridge the C and G pads with solder for each channel that you install a thermocouple. Bridging
these pads reduces the noise present when you take temperature readings, and helps to obtain a more accurate
temperature reading. The C, V, and G pads are all open when the board is shipped.
How to add and remove a solder bridge
To add a solder bridge to a solder gap switch, place a drop of solder on one of the pads and pull the soldering
iron perpendicular to the pads from their center. To remove a solder bridge, slide the soldering iron toward one
pad or the other. Take care not to overheat the solder, or the pads may lift.

Configuring the A/D board
Use InstaCal to change the following configuration options on your DAS08 or DAS16 Series board.

Single-ended mode
DAS08 setup: The input mode of the A/D board must be single-ended to be compatible with the CIO-EXP16

outputs. Some of the boards in the DAS08 series have differential inputs that can be converted to single-ended
inputs. Refer to the user's manual for your hardware for information on conversion to single-ended inputs.
DAS16 setup: The input mode of the A/D board must be single-ended to be compatible with the CIO-EXP16

outputs. Most of the DAS16 series is switch-selectable for either 8 differential or 16 single ended inputs. Whenused with the CIO-EXP16, set the switch to 16 channel, single-ended mode.

Range
If the range of your A/D board is switch-selectable, and you are using thermocouples, set the range of the DAS
board to ±5 V, if available, or ±10 V if not. Some software packages base the calculation of temperature onthese ranges only.
If you are not using thermocouples, set the range of the DAS board to accommodate the maximum output
expected from the CIO-EXP16 board.

Polarity
If your A/D board has a UNI / BIP switch for setting the range to either unipolar or bipolar, the preferred setting
is BIP (bipolar).
If the range on your A/D board is fully programmable, the software you use for temperature measurement will
determine the correct range to use.

Calibrating the CIO-EXP16
You should calibrate the CIO-EXP16 after you first connect to a A/D board, if you change the gain setting of
the input amplifier, and at 6 month intervals.

17

Chapter 3

Functional Details
CIO-EXP16 inputs
The CIO-EXP16 inputs are screw terminals which will accept 12-22 AWG wire. Each channel has a screw
terminal for signal high, signal low and ground.
The inputs are differential, which require three connections from the signal source to the CIO-EXP16 — Signal
High, Signal Low, and Signal Ground. A typical connection is shown in Figure 10.

Signal High
Signal Low
Low Level GroundFigure 10. Differential channel connections

Figure 11 shows a block diagram of the board’s 16 analog inputs. One input is selected by the four MUX
address lines that are controlled by the A/D board.
CH15 HIGH
CH15 LOW4MUX ADDR

MUX
HI-507
EXP out to the
DAS board

CH8 HIGH
CH8 LOWAMP
INA1 10GND

GroundCH7 HIGH
CH7 LOW
MUX
HI-507
CH0 HIGH
CH0 LOW

Gain
SwitchGND

Figure 11. Analog inputs block diagram

Connecting to a signal source
You can connect analog inputs to the CIO-EXP16 in either a floating differential or differential configuration.
Before connecting to a signal source, measure the voltage between the signal ground at the signal source andground at the PC. Do not connect to a signal source if the voltage difference exceeds 10 V, as you will not beable to obtain a reading.
Caution!

DO NOT connect to the signal if the voltage exceeds 30 V — voltages over 30 V will damage theboard and possibly the computer.

18

CIO-EXP16 User's Guide

Functional Details

Floating differential input
A floating differential input has two wires from the signal source, and a 100 K ground reference resistor
installed at the CIO-EXP16 input. The two signals from the signal source are Signal High (CH#-HI) and Signal
Low (CH#-LO). The reference resistor is connected between the CH#-LO and #-G (Signal Ground) pins.
Use a floating differential hookup when the signal source is floating with respect to ground, such as a battery, 420 mA transmitter or thermocouple, and the lead lengths are long or subject to electromagnetic interference(EMI) pickup.
A thermocouple is an example of a floating differential signal source. Instead of using an external 100 K
resistor, add a solder bridge between the 'G' pads to enable a ground reference. The floating differential input
will reject up to 10 V of EMI.
Caution!

Use a voltmeter to verify that the signal source is floating, or you may damage the CIO-EXP16
and/or your computer.

Differential input
A differential signal uses three wires from the signal source — Signal High (CH#-HI), Signal Low (CH#-LO)and Signal Ground (#-G).
With a differential configuration, you can connect the CIO-EXP16 to a signal source with a ground that isdifferent from the PC ground, but with less than 10 V difference, and still make a true measurement of thesignal between CH# HI and CH# LO. An example of this is a laboratory instrument with its own wall plug,where there are sometimes differences in wall grounds between outlets.
Information on signal connections
For general information about signal connection and configuration, refer to the Guide to Signal Connections
on our web site at www.mccdaq.com/pdfs/DAQ-Signal-Connections.pdf.

Thermocouples
A thermocouple is made of two dissimilar wires that react electrically when in contact with each other. The
reaction produces a voltage which is dependent on the temperature at the point where the two metals touch.
There is a reaction at every point where dissimilar metals (the thermocouple wire) touch, including the screw
terminal where the thermocouple wire is connected to the CIO-EXP16 board.
To process thermocouple signals, the CIO-EXP16 provides cold junction compensation (CJC), open
thermocouple detect (OTD) and stable amplification for accurate temperature measurements.
Figure 12 shows a thermocouple connected to one channel of the CIO-EXP16. The thermocouple has a positive
and a negative lead. If you're not sure which is the positive lead and which is the negative lead, make a test
hookup and use a match to heat the thermocouple. If the temperature reading goes down, switch the leads.
3.9M
-15 V
Thermocouple
positive lead

10K

High

C
1 µF

10K

Low
Thermocouple
negative lead

High

V

Low

Ground100K

GGroundC = Filter capacitor, pad open. V = Open TC Detect, pad open. G = Reference to ground, pad open.
Pads are located on the circuit side. All pads must be closed when thermocouples are used.

Figure 12. Typical thermocouple connection

19

CIO-EXP16 User's Guide

Functional Details

Cold junction compensation
The CIO-EXP16 has a semiconductor temperature sensor to measure the temperature of the board around thescrew terminals—this is called the cold junction temperature. This sensor provides a stable, accurate and linear
output which is temperature-dependent. The cold junction temperature is required to accurately calculate thethermocouple temperature. This is known as cold junction compensation (CJC). You can map the sensor output
to one of the A/D board's analog inputs using the CJC output to DAS jumper block.
The CJC reference is required for accurate temperature readings
The CJC temperature reference is universally used by software to compensate for the voltage induced at thecold junction (the area around the screw terminals). If you don't supply a CJC reference your temperature
readings may be inaccurate.

Open thermocouple detect
You enable open thermocouple detect (OTD) by closing the channel’s associated 'V' pad with a solder bridge.
OTD applies a full-scale negative voltage to the high side of the thermocouple signal. If a thermocouple opens,
the OTD voltage drives the signal on that channel to negative full-scale.
Design your software program to recognize when a negative full-scale condition exists, since the input is pulled
to negative full-scale if the thermocouple wire is broken or disconnected. Most software is set up to alarm for an
open thermocouple when a temperature falls to negative full-scale.
The CIO-EXP16 will accurately measure thermocouples when the 'V' pad is open, but without OTD protection
enabled.

Low pass filter
A low pass filter is implemented by closing the 'C' pad. When bridged, a 1 µF capacitor is connected across thesignal’s high and low inputs, forming a low-pass filter. The bandwidth of this filter is 7 Hz. Signals changing at
rates greater than 7 times per second are damped. The low pass filter helps to reject noise picked up along thethermocouple wire. Since temperature measurement is generally a ‘low frequency’ application, the filter does
not affect the temperature measurement.
The CIO-EXP16 will accurately measure thermocouples when the 'C' pad is open, but the measurements may
fluctuate due to noise present on the thermocouple wire.

Ground reference
The CIO-EXP16 inputs are fully differential, which help reject noise on thermocouple wires. Close the ‘G’ padthermocouples to work properly. The 'G' pad provides a reference from ground to the analog low input via a 100
K resistor. When closed, enough current passes through the resistor to provide a reference to ground. The
analog high and low inputs are still able to float within the common mode range.

Input impedance
When you leave the V and G pads open, the input impedance is greater than 100 M ohms. When you short the
V and G pads, the input impedance is 100 k ohms.

Amplification and thermocouples
The voltage from a thermocouple is very low and must be amplified to take advantage of the A/D board’s full
resolution. Use the GAIN switch to set the amplification of the CIO-EXP16 board's 16 analog inputs (see Figure
8 on page 16).
The following table lists the theoretical amplifier output voltage at maximum temperature for each gain. In mostcases, the range on the A/D board is set to ±5 V. The maximum voltage for some thermocouple/gain
combinations can exceed the maximum A/D input range (typically 5 V), or even the maximum output voltageof the CIO-EXP16 board (±10 V).

20

CIO-EXP16 User's Guide

Functional Details

Output voltage vs gain at maximum temperature
Type

J
K
T
E
S
R

Min Temp °C

0
−200
−200
−200
0
0

Max Temp °C

mV at
Max

Gain / Output Volts @ Max Temp
100

200

300

500

800

750
1250

42.28
50.63

4.2
5.1

8.5
10.1

12.7
15.2

21.1
25.3

33.8
40.5

350
900

17.82
68.78

1.8
6.9

3.6
13.8

5.3
20.6

8.9
34.4

14.3
55.0

1450
1450

14.97
16.74

1.5
1.7

3.0
3.3

4.5
5.0

7.5
8.4

12.0
13.4

The table below lists the maximum readable temperatures for each gain and thermocouple type for an A/Drange of ±5V.
Gain vs maximum readable temperatures
Type

J
K
T
E
S
R

Gain / Max. Readable Temps. with A/D Range = ±5 V
10

100

200

300

500

800

MAX
MAX
MAX
MAX
MAX
MAX

MAX
1232 °C
MAX
661°C
MAX
MAX

457°C
602°C
MAX
350°C
MAX
MAX

307°C
406°C
330°C
244°C
MAX
1445°C

186°C
246°C
214°C
152°C
1035°C
961°C

117°C
152°C
140°C
98°C
697°C
658°C

To read the maximum usable temperature for type K and E thermocouples, set the gain to X10 or less.
After you change the gain setting, calibrate the CIO-EXP16 using the InstaCal utility.

21Chapter 4

Programming and Developing Applications
After following the installation instructions in Chapter 2, your board should now be installed and ready for use.
In general there may be no correspondence among registers for different boards. Software written at the registerlevel for other models will not function correctly with your board.

Programming languages
Measurement Computing’s Universal Library provides access to board functions from a variety of Windows
programming languages. If you are planning to write programs, or would like to run the example programs for
Visual Basic or any other language, please refer to the Universal Library User's Guide (available on our website at www.mccdaq.com/PDFmanuals/sm-ul-user-guide.pdf).

Packaged applications programs
Many packaged application programs now have drivers for your board. If the package you own does not have
drivers for your board, please fax or e-mail the package name and the revision number from the install disks.
We will research the package for you and advise how to obtain drivers.
Some application drivers are included with the Universal Library package, but not with the application package.
If you have purchased an application package directly from the software vendor, you may need to purchase ourUniversal Library and drivers. Please contact us by phone, fax or e-mail:

Phone: 508-946-5100 and follow the instructions for reaching Tech Support.
Fax: 508-946-9500 to the attention of Tech Support
Email: techsupport@mccdaq.com

22Chapter 5

Specifications
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.

Analog input
Table 1. Analog input specifications
Parameter

Specification

Number of channels
Input range
Gain
Calibration

16 differential (1 bank)±10 V
Switch selectable by bank, additive values of X1, X10, X100, X200 and X500
Two offset potentiometers per bank (16 channels) and one Cold Junction
Compensation adjustment potentiometer per board.
Gain = 1
0.002% typical, 0.02% max
Gain = 10
0.005% typical, 0.05% max
Gain = 100
0.01% typical, 0.1% max
Gain = 200
0.02% typical, 0.2% max
Gain = 500
0.05% typical, 0.5% max
Gain = 1
0.0005% typical, 0.005%
Gain = 100.001% typical, 0.01% max
Gain = 100
0.002% typical, 0.01% max
Gain = 200
0.003% typical, 0.01% max
Gain = 500
0.005% typical, 0.02% max
Gain = 1± 20 ppm / °C
Gain = 10± 20 ppm / °C
Gain = 100± 40 ppm / °C
Gain = 200± 60 ppm / °C
Gain = 500± 100 ppm / °C
Offset± 15 µV / °C
±10 V
90 dB
7 Hz, selectable through solder bridge (C pad)
-50 mV at positive input when thermocouple is open, selectable through solder
bridge (V pad)
100k ohms to ground, selectable through solder bridge (G pad)
V and G pads open:
2 nA typical, 6 nA max
 V and G pads open:>100 Meg Ohms min V and G pads shorted
100 k Ohms min Power on:±35 V
 Power off:
±20 V

Gain error

Non-linearity

Temperature coefficient

Common mode range
CMRR @ 60 Hz
Input filter
Open thermocouple detect
Input ground reference
Input leakage current
Input impedance
Absolute maximum input voltage

Cold junction compensation
Table 2. Cold junction compensation specifications
Parameter

Specification

CJC output voltage
CJC zero crossing

24 mV / °C
0 mV at 0 °C

23

CIO-EXP16 User's Guide

Specifications

Analog output
Table 3. Analog output specifications
Parameter

Specification

Number of channels
Output voltage range
Configuration
Current drive
Output coupling
Output impedance

2 (one from multiplexed inputs, one from CJC circuit)±10 V
Single – ended±5 mA
DC
0.1 Ohms max

Digital input
Table 4. Analog input specifications
Parameter

Specification

Digital input:

74LS14

Configuration
Number of channels
Input highInput low

Four bits for selecting multiplexer channel 0 through 15
4 input
2.0 volts min, 7 volts absolute max
0.8 volts max, -0.5 volts absolute minPower consumption
Table 5. Power consumption specifications
Parameter

Specification+5 V

120 mA typical, 155 mA max

Environmental
Table 6. Environmental specifications
Operating temperature range
Storage temperature range
Humidity

0 to 60 °C-40 to 100 °C
0 to 90% non-condensing

24

CIO-EXP16 User's Guide

Specifications

Main connector and pin out
Table 7. Connector specifications
Connector typeCompatible cables with connector P1
Compatible cables with connector P2

P1 and P2: 37-pin D type connectors
C37FF-x (connecting to additional CIO-EXP16 boards)
 C37FF-x (connecting to a DAS08 board) C-EXP2DAS16-10 (connecting to a DAS16 board)
Table 8. Connector pin out

Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

Signal Name
+12V PC Bus
NC
NC
NC
NC
NC
MUX Addr 1
MUX Addr 2
MUX Addr 3
MUX Addr 4
Output 15
Output 14
Output 13
Output 12
Output 11
Output 10
Output 9
LLGND / Output
NC / LLGND

Pin
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

Signal Name
-12V PC Bus
NC
NC
NC
NC
NC
NC
NC
Power GND
+5V
Output 7
Output 6
Output 5
Output 4
Output 3
Output 2
Output 1
Output 025

Declaration of Conformity
Manufacturer:
Address:

Category:

Measurement Computing Corporation
10 Commerce Way
Suite 1008
Norton, MA 02766
USAElectrical equipment for measurement, control and laboratory use.

Measurement Computing Corporation declares under sole responsibility that the product

CIO-EXP16
to which this declaration relates is in conformity with the relevant provisions of the following standards or otherdocuments:
EU EMC Directive 89/336/EEC: Electromagnetic Compatibility, EN55022 (1987), EN50082-1
Emissions: Group 1, Class B


EN55022 (1987): Radiated and Conducted emissions.

Immunity: EN50082-1


IEC 801-2 (1987): Electrostatic Discharge immunity, Criteria A.
IEC 801-3 (1984): Radiated Electromagnetic Field immunity Criteria A.
IEC 801-4 (1988): Electric Fast Transient Burst immunity Criteria A.

Declaration of Conformity based on tests conducted by Chomerics Test Services, Woburn, MA 01801, USA in
November, 1995. Test records are outlined in Chomerics Test Report #EMI0168A.95.
We hereby declare that the equipment specified conforms to the above Directives and Standards.

Carl Haapaoja, Director of Quality Assurance

Measurement Computing Corporation
10 Commerce Way
Suite 1008
Norton, Massachusetts 02766(508) 946-5100
Fax: (508) 946-9500
E-mail: info@mccdaq.com
www.mccdaq.com