USB-204
Analog and Digital I/O

User's Guide

January 2019. Rev 7© 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.
© 2019 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 USB-204.docx

Table of Contents
Preface

About this User's Guide ....................................................................................................................... 5
What you will learn from this user's guide ......................................................................................................... 5
Conventions in this user's guide ......................................................................................................................... 5
Where to find more information ......................................................................................................................... 5
Chapter 1

Introducing the USB-204 ...................................................................................................................... 6
Functional block diagram ................................................................................................................................... 6
Chapter 2

Installing the USB-204 .......................................................................................................................... 7
Unpacking........................................................................................................................................................... 7
Installing the software ........................................................................................................................................ 7
Installing the hardware ....................................................................................................................................... 7
Calibrating the hardware..................................................................................................................................... 7
Factory calibration ............................................................................................................................................................ 7
Field calibration ................................................................................................................................................................ 7

Chapter 3

Functional Details ................................................................................................................................. 8
Analog input acquisition modes ......................................................................................................................... 8
Software paced mode ........................................................................................................................................................ 8
Hardware paced mode....................................................................................................................................................... 8External components .......................................................................................................................................... 8

Screw terminals................................................................................................................................................................. 9USB connector .................................................................................................................................................................. 9
LED indicators .................................................................................................................................................................. 9Signal connections ............................................................................................................................................ 10

Analog input ....................................................................................................................................................................10
External pacer I/O ............................................................................................................................................................10
Digital I/O ........................................................................................................................................................................10
Trigger input ....................................................................................................................................................................11
Counter input ...................................................................................................................................................................11
Voltage output .................................................................................................................................................................11
Ground .............................................................................................................................................................................11

Mechanical drawings ........................................................................................................................................ 12
Chapter 4

Specifications ...................................................................................................................................... 14
Analog input ..................................................................................................................................................... 14
Accuracy ........................................................................................................................................................... 14
Analog input DC voltage measurement accuracy ............................................................................................................14
Noise performance ...........................................................................................................................................................15

Analog input calibration ................................................................................................................................... 15
Digital input/output........................................................................................................................................... 15External digital trigger ...................................................................................................................................... 16External pacer input/output............................................................................................................................... 16
Counter ............................................................................................................................................................. 17
Memory ............................................................................................................................................................ 17Power ................................................................................................................................................................ 17
USB specifications ........................................................................................................................................... 18
Environmental .................................................................................................................................................. 183

USB-204 User's Guide

Mechanical ....................................................................................................................................................... 18
Screw terminal connector ................................................................................................................................. 18
EU Declaration of Conformity ............................................................................................................ 19

HM USB-204.docx

Preface

About this User's Guide
What you will learn from this user's guideThis user's guide describes the Measurement Computing USB-204 data acquisition device and lists device
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 USB-204 hardware is available on our website at www.mccdaq.com. You canalso 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.

5Chapter 1

Introducing the USB-204
The USB-204 is a USB 2.0 full-speed device that provides the following features:










Eight single-ended 12-bit analog inputs
500 kS/s max sample rate
Eight individually configurable digital I/O channels
32-bit counter input
Digital trigger input
External pacer clock inputInternal/external pacer clock output
User voltage output
Two screw terminal banks for field wiring connections

The USB-204 is powered by the +5 V USB supply from your computer; no external power is required. A USB
cable is shipped with the device.

Functional block diagram
Device functions are illustrated in the block diagram shown here.

Figure 1. USB-204 functional block diagram

6

Chapter 2

Installing the USB-204
UnpackingAs with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the device from its packaging, ground yourself using a wrist strap or by simply
touching the computer chassis or other grounded object to eliminate any stored static charge.
Contact us immediately if any components are missing or damaged.

Installing the software
Refer to the MCC DAQ Quick Start and the USB-204 product page on our website for information about thesoftware that supports the device.
Install the software before you install your device
The driver needed to run the USB-204 is installed with the software. Therefore, you need to install the software
package you plan to use before you install the hardware.

Installing the hardware
Connect the USB cable to an available USB port on the computer or to an external USB hub connected to thecomputer. Connect the other end of the cable to the USB connector on the device. No external power isrequired.
When connected for the first time, a Found New Hardware dialog opens when the operating system detects thedevice. When the dialog closes, the installation is complete. The device Status LED turns on after the device issuccessfully installed.
If the Status LED turns off
If communication is lost between the device and the computer, the Status LED turns off. To restore
communication, disconnect the USB cable from the computer and then reconnect it. This should restore
communication, and the Status LED should turn on.

Calibrating the hardware
Factory calibration
The Measurement Computing Manufacturing Test department performs the initial factory calibration. Returnthe device to Measurement Computing Corporation when calibration is required. The recommended calibrationinterval is one year.

Field calibration
Field calibration is not supported.

7

Chapter 3

Functional Details
Analog input acquisition modes
The USB-204 can acquire analog input data in two different modes – software paced and hardware paced.

Software paced mode
You can acquire one analog sample at a time in software paced mode. You initiate the A/D conversion with asoftware command. The analog value is converted to digital and returned to the computer. You can repeat thisprocedure until you have the total number of samples that you want.
The maximum throughput sample rate in software paced mode is system-dependent.

Hardware paced mode
You can acquire data from up to eight channels in hardware paced mode. The analog data is continuously
acquired and converted to digital values until you stop the scan. Data is transferred in blocks of 32 samples fromthe device to the memory buffer on your computer.
The maximum continuous scan rate is an aggregate rate. The total acquisition rate for all channels cannot
exceed 500 kS/s. The following table lists the scan rate when scanning from one to eight channels.
Maximum continuous scan rate
# channels
scannedScan rate(kS/s)

1
2
3
4
5
6
7
8

500
250
166.67
125
100
83.33
71.43
62.50

You can start a hardware paced continuous scan with either a software command or with an external hardware
trigger event.

External components
The external components on the USB-204 are shown in Figure 2.

1
2
3

Screw terminal pins 1 to 16
Screw terminal pins 17 to 32
Status LED

4
5

Activity LED
USB connector

Figure 2. USB-204 external components

8USB-204 User's Guide

Functional Details

Screw terminals
The screw terminals provide the following connections:









Eight single-ended analog inputs (CH0 to CH7)
Eight digital I/O (DI00 to DI07)
External pacer clock input (AICKI)
External pacer clock output (AICKO)
Digital trigger input (TRIG)Counter input (CTR)
User voltage output (+VO)
Analog ground reference (AGND) and digital ground reference (GND)

Figure 3. USB-204 pinout

USB connector
The USB connector provides +5 V power and communication. No external power supply is required.

LED indicators
The device has two LED indicators – Status and Activity.
The Status LED turns on when the device is detected and installed on the computer.
The Activity LED blinks when data is transferred, and is off otherwise.

Refer to Figure 2 on page 8 for the location of each LED.

9

USB-204 User's Guide

Functional Details

Signal connections
Analog input
You can connect up to 8 single-ended inputs to screw terminals CH0 to CH7. The input voltage range is ±10 V.
Single-ended mode requires two wires; connect one wire to the signal you want to measure (CHx) and connect asecond wire to the analog ground reference (AGND).

External pacer I/O
The USB-204 provides one external clock input (AICKI) and one clock output (AICKO) for the analog input
pacer. You can connect an external clock signal to AICKI.
When using the internal clock, AICKO outputs the ADC sample clock.

Digital I/O
You can connect up to eight digital I/O lines to DIO0 through DIO7. The digital I/O terminals can detect thestate of any TTL-level input. Refer to the schematic shown in Figure 4.

Figure 4. Schematic showing switch detection by digital channel DIO0

If you set the switch to the +5 V input, DIO0 reads TRUE (1). If you move the switch to GND, DIO0 reads
FALSE (0).
Internal pull-up/down configuration
The digital port has 47 kΩ resistors that you can configure as pull-up or pull-down with an internal jumper.
Unconnected inputs are pulled low by default to 0 V through 47 kΩ resistors. The pull-up/pull-down voltage iscommon to all 47 kΩ resistors.
You can change the configuration with an internal jumper. You must remove the cover from the device in orderto access the jumper. To remove the cover, unscrew the four screws on the device bottom.
Caution! The discharge of static electricity can damage some electronic components. Before removing thedevice from its housing, either ground yourself using a wrist strap or touch the computer chassis orother grounded object to eliminate any stored static charge.
Figure 5 shows the location of the pull-up/down jumper in relation to the USB connector.

Figure 5. Pull-up/down jumper location

10

USB-204 User's Guide

Functional Details

Figure 6 shows the jumper configured for pull-down.

Figure 6. Pull-down jumper

Configure the jumper for pull-up to pull the digital inputs high (+5V).
Proper LED alignment
When placing the circuit board within the housing, align the board LEDs with the top of the housing before
attaching the housing bottom.

Trigger input
The TRIG terminal is an external digital trigger input. The trigger mode is software-selectable for edge- orlevel-sensitive. The trigger is automatically re-armed after it is activated.

Counter input
The CTR terminal is a 32-bit event counter that can accept frequency inputs up to 1 MHz. The internal counterincrements when the TTL levels transition from low to high.

Voltage output
The user voltage output (+VO) terminal can output up to 100 mA maximum at approximately +5V. You can use
this terminal to supply power to external devices or circuitry.
Caution! The +VO terminal is an output. Do not connect to an external power supply or you may damage
the device and possibly the computer.

GroundThe analog ground (AGND) terminals provide a common ground for all analog channels. The digital ground(GND) terminals provide a common ground for the digital, counter, pacer I/O, and power terminal.
For more information about signal connections
For more information about analog and digital signal connections, refer to the Guide to DAQ Signal
Connections on our website at www.mccdaq.com/support/DAQ-Signal-Connections.aspx.

11USB-204 User's Guide

Functional Details

Mechanical drawings

Figure 7. Circuit board (top) and housing dimensions

12USB-204 User's Guide

Functional Details

Figure 8. Housing bottom dimensions

13

Chapter 4

Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.

Analog input
Table 1. General analog input specifications
Parameter

Conditions

Specification

A/D converter type
ADC resolution

Successive approximation
12 bits

Number of channels

8 single-ended

Input voltage range
Absolute maximum input
voltageCHx relative to AGND

Input impedance
Input bias current

Input bandwidth
Maximum working voltage
Crosstalk
Input coupling
Sampling rate

10 V input
0 V input–10 V input
Small signal (–3 dB)
Input range relative to
AGND
Adjacent channels, DC to
10 kHz–75 dBDC
0.016 S/s to 500 kS/s, software-selectable
500 kS/s max
 Internal A/D clock Pacer input terminal AICKI
Up to eight unique, ascending channels
33 to 4000 S/s typ, system dependent
500 kS/s max, system dependent
15 minutes min

Internal pacer
External pacer

Sample clock source
Channel queue
Throughput±10 V
 ±25 V max (power on)
 ±25 V max (power off) 1 MΩ (power on)
 1 MΩ (power off)
–12 µA
2 µA
12 µA
1.0 MHz±10.1 V max

Software paced
Hardware paced

Warm-up time

Accuracy
Analog input DC voltage measurement accuracy
Table 2. DC Accuracy components and specifications. All values are (±)

Range

Gain error(% of reading)

Offset error(mV)Absolute accuracy
at Full Scale
(mV)

±10V

0.098

11

20.8

14

Gain temperature
coefficient(% reading/°C)

Offsettemperature
coefficient(mV/°C)

0.016

0.87

USB-204 User's Guide

Specifications

Noise performance
For the peak to peak noise distribution test, the input channel is connected to AGND at the input terminal block,and 12,000 samples are acquired at the maximum throughput.
Table 3. Noise performance specifications
Range

Counts

LSBrms

±10 V

5

0.76

Analog input calibration
Table 4. Analog input calibration specifications
Parameter

Specification

Recommended warm-up time
Calibration method
Calibration interval

15 minutes min
Factory
1 yearDigital input/output
Table 5. Digital input specifications
Parameter

Specification

Digital type
Number of I/O
Configuration
Pull-up configuration

TTL
8
Each bit may be configured as input (power on default) or output
The port has 47 kΩ resistors that may be configured as pull-up or pull-down with aninternal jumper. The factory configuration is pull-down.
33 to 4000 port reads/writes per second typical, system dependent

Digital I/O transfer rate(system-paced)
Input low voltage threshold
Input high voltage threshold
Input voltage limits

Output high voltage
Output low voltage
Output current

0.8 V max
2.0 V min
5.5 V absolute max–0.5 V absolute min
0 V recommended min
4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –24 mA)
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 24 mA)±24 mA max

15

USB-204 User's Guide

Specifications

External digital trigger
Table 6. External digital trigger specifications
Parameter

Specification

Trigger source
Trigger mode

TRIG input
Software configurable for edge or level sensitive, rising or falling edge, high or low
level. Power on default is edge sensitive, rising edge.
1 µs + 1 pacer clock cycle max
125 ns min
Schmitt trigger, 47 kΩ pull-down to ground1.01 V typ
0.6 V min
1.5 V max
2.43 V typ
1.9 V min3.1 V max
1.42 V typ
1.0 V min
2.0 V max
5.5V absolute max–0.5V absolute min
0V recommended min

Trigger latency
Trigger pulse width
Input type
Schmitt trigger hysteresis

Input high voltage threshold

Input low voltage threshold

Input voltage limits

External pacer input/output
Table 7. External pacer I/O specifications
Parameter

Specification

Terminal names
Terminal types

AICKI, AICKOAICKI:AICKO:AICKI:AICKO:

Input, active on rising edge
Output, power on default is 0 V, active on rising edge
Receives pacer clock from external source
Outputs internal pacer clock

Input clock rate
Clock pulse width

500 kHz max
AICKI:AICKO:

400 ns min
400 ns min

Input type
Schmitt trigger hysteresis

Schmitt trigger, 47 kΩ pull-down to ground1.01 V typ
0.6 V min
1.5 V max
2.43 V typ
1.9 V min3.1 V max
1.42 V typ
1.0 V min
2.0 V max
5.5 V absolute max–0.5 V absolute min
0 V recommended min
4.4 V min (IOH = –50 µA)
3.80 V min (IOH = –8 mA)
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 8 mA)±8 mA max

Terminal descriptions

Input high voltage threshold

Input low voltage threshold

Input voltage limits

Output high voltage
Output low voltage
Output current

16

USB-204 User's Guide

Specifications

CounterTable 8. CTR specifications
Parameter

Specification

Pin name
Number of channels
Resolution
Counter type
Input typeCounter read/write rates(software paced)CTR
1 channel
32-bitEvent counter
Schmitt trigger, 47 kΩ pull-down to ground
33 to 4,000 reads/writes per second typ, system dependent

Schmitt trigger hysteresis

1.01 V typ
0.6 V min
1.5 V max
2.43 V typ
1.9 V min3.1 V max
1.42 V typ
1.0 V min
2.0 V max
5.5 V absolute max–0.5 V absolute min
0 V recommended min
1 MHz max
25 ns min
25 ns min

Input high voltage threshold

Input low voltage threshold

Input voltage limits

Input frequency
High pulse width
Low pulse width

MemoryTable 9. Memory specifications
Parameter

Specification

Data FIFO
Non-volatile memory

12 K (12,288) analog input samples
2 KB (768 B calibration storage, 256 B UL user data, 1 KB DAQFlex user data)

Power
Table 10. Power specifications
Parameter

Conditions

Specification

Supply current

Typical (Note 1)
Maximum (including user voltage, DIO andAICKO loading)

150 mA
500 mA

User voltage output
terminal (+VO)
User voltage output current

4.25 V min, 5.25 V max
100 mA max

Note 1: This is the total quiescent current requirement for the device which includes up to 10 mA for the Status LED. Thisvalue does not include any potential loading of the digital I/O bits, AICKO, or user voltage.

17

USB-204 User's Guide

Specifications

USB specifications
Table 11. USB specifications
Parameter

Specification

USB device type
Device compatibility
USB cable type

USB 2.0 (full-speed)
USB 1.1, USB 2.0
A-B cable, UL type AWM 2725 or equivalent. (minimum 24 AWG VBUS/GND,
minimum 28 AWG D+/D–)
3 m (9.84 ft) max

USB cable length

Environmental
Table 12. Environmental specifications
Parameter

Specification

Operating temperature range
Storage temperature range
Humidity

0 °C to 55 °C max–40 °C to 85 °C max
0% to 90% non-condensing max

Mechanical
Table 13. Mechanical specifications
Parameter

Specification

Dimensions (L × W × H)

117.86 × 82.80 × 28.96 mm (4.64 × 3.26 × 1.14 in.) max

Screw terminal connector
Table 14. Screw terminal connector specifications
Parameter

Specification

Connector type
Wire gauge range

Screw terminal
16 AWG to 30 AWG
Table 15. Screw terminal pinout

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

Signal name
GND
TRIG
CTR
AICKI
AICKO
GND
+VO
GND
DIO7
DIO6
DIO5
DIO4
DIO3
DIO2
DIO1
DIO0

Pin description
Digital ground
Digital trigger input
Counter input
External clock pacer input
External clock pacer output
Digital ground
User voltage output
Digital ground
DIO channel 7
DIO channel 6
DIO channel 5
DIO channel 4
DIO channel 3
DIO channel 2
DIO channel 1
DIO channel 0

Pin
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

18

Signal name
AGND
CH7
AGND
CH6
AGND
CH5
AGND
CH4
AGND
CH3
AGND
CH2
AGND
CH1
AGND
CH0

Pin description
Analog ground
Channel 7
Analog ground
Channel 6
Analog ground
Channel 5
Analog ground
Channel 4
Analog ground
Channel 3
Analog ground
Channel 2
Analog ground
Channel 1
Analog ground
Channel 0

EU Declaration of Conformity
According to ISO/IEC 17050-1:2010
Manufacturer:
Address:

Product Category:
Date and Place of Issue:
Test Report Number:

Measurement Computing Corporation
10 Commerce Way
Norton, MA 02766
USAElectrical equipment for measurement, control and laboratory use.
July 20, 2016, Norton, Massachusetts USA
EMI6206.12

Measurement Computing Corporation declares under sole responsibility that the productUSB-204
is in conformity with the relevant Union Harmonization Legislation and complies with the essential
requirements of the following applicable European Directives:
Electromagnetic Compatibility (EMC) Directive 2014/30/EU
Low Voltage Directive 2014/35/EU
RoHS Directive 2011/65/EU
Conformity is assessed in accordance to the following standards:
EMC:
Emissions: EN 61326-1:2013 (IEC 61326-1:2012), Class A
 EN 55011: 2009 + A1:2010 (IEC CISPR 11:2009 + A1:2010), Group 1, Class A
Immunity: EN 61326-1:2013 (IEC 61326-1:2012), Controlled EM Environments EN 61000-4-2:2008 (IEC 61000-4-2:2008)
 EN 61000-4-3 :2010 (IEC61000-4-3:2010)
Safety: EN 61010-1:2010 (IEC 61010-1:2010)
Environmental Affairs:
Articles manufactured on or after the Date of Issue of this Declaration of Conformity do not contain any of therestricted substances in concentrations/applications not permitted by the RoHS Directive.

Carl Haapaoja, Director of Quality Assurance

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

NI Hungary Kft
H-4031 Debrecen, Hátar út 1/A, Hungary
Phone: +36 (52) 515400
Fax: +36 (52) 515414
http://hungary.ni.com/debrecen