Omega OM-USB-1208HS User guide

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It is the policy of OMEGA Engineering, Inc. to comply with all worldwide safety and EMC/EMI
regulations that apply. OMEGA is constantly pursuing certification of its products to the European New
Approach Directives. OMEGA will add the CE mark to every appropriate device upon certification.

The information contained in this document is believed to be correct, but OMEGA accepts no liability for any
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WARNING: These products are not designed for use in, and should not be used for, human applications.

Table of Contents

Preface

About this User's Guide ....................................................................................................................... 4

What you will learn from this user’s guide ......................................................................................................... 4

Conventions in this user's guide ......................................................................................................................... 4

Where to find more information ......................................................................................................................... 4

Chapter 1

Introducing the OM-USB-1208HS Series ............................................................................................ 5

Software features ................................................................................................................................................ 6

Chapter 2

Installing a OM-USB-1208HS Series Device ....................................................................................... 7

What comes with your shipment? ....................................................................................................................... 7

Hardware .......................................................................................................................................................................... 7

Documentation .................................................................................................................................................................. 7

Unpacking ........................................................................................................................................................... 7

Installing the software ........................................................................................................................................ 7

Installing the hardware ....................................................................................................................................... 7

Calibrating a OM-USB-1208HS Series Device .................................................................................................. 8

Chapter 3

Functional Details ................................................................................................................................. 9

Analog input acquisition modes ......................................................................................................................... 9

Software paced mode ........................................................................................................................................................ 9

Hardware paced mode ....................................................................................................................................................... 9

External components .......................................................................................................................................... 9

USB connector .................................................................................................................................................................10

LEDs ................................................................................................................................................................................10

Screw terminals................................................................................................................................................................10

Signal connections ............................................................................................................................................ 11

Analog input ....................................................................................................................................................................11

Analog output ..................................................................................................................................................................12

External clock I/O ............................................................................................................................................................12

Digital I/O ........................................................................................................................................................................12

Counter I/O ......................................................................................................................................................................13

Timer output ....................................................................................................................................................................13

Trigger input ....................................................................................................................................................................14

Power outputs ..................................................................................................................................................................14

Ground .............................................................................................................................................................................14

Chapter 4

Specifications ...................................................................................................................................... 15

Analog input ..................................................................................................................................................... 15

Analog output (OM-USB-1208HS-2AO, OM-USB-1208HS-4AO) ................................................................ 17

External trigger ................................................................................................................................................. 18

External clock input/output............................................................................................................................... 18

Timer ................................................................................................................................................................ 19

Memory ............................................................................................................................................................ 19

Power ................................................................................................................................................................ 20

USB specifications ........................................................................................................................................... 20

Environmental .................................................................................................................................................. 21

Main connector and pinout ............................................................................................................................... 21

3

Preface

About this User's Guide

What you will learn from this user’s guide

This user's guide describes the Omega Engineering OM-USB-1208HS Series data acquisition devices and lists
device specifications.

Conventions in this user's guide

For more information about …

Text presented in a box signifies additional information and helpful hints related to the subject matter you are
reading.

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 OM-USB-1208HS Series hardware is available on our website at

www.omega.com. You can also contact Omega Engineering by phone, fax, or email with specific questions.

 Phone: [phone]
 Fax: [phone]
 Email: [email protected]

4

Chapter 1

Introducing the OM-USB-1208HS Series

The OM-USB-1208HS Series includes the following devices:

 OM-USB-1208HS
 OM-USB-1208HS-2AO
 OM-USB-1208HS-4AO

These devices are USB 2.0 high-speed devices supported under popular Microsoft® Windows® operating
systems. The OM-USB-1208HS Series is compatible with both USB 1.1 and USB 2.0 ports, although the speed
of the module maybe limited when using USB 1.1 ports.

Each OM-USB-1208HS Series device provides the following features:

 8 single-ended (SE) or four differential (DIFF) analog input channels
 16 individually configurable digital I/O channels
 Two 32-bit counter input channels that count TTL pulses
 One 32-bit timer output channel
 Screw terminals for field wiring connections

The OM-USB-1208HS-2AO also provides two 12-bit analog output channels, and the OM-USB-1208HS-4AO
provides four 12-bit analog output channels.

5

OM-USB-1208HS Series User's Guide Introducing the OM-USB-1208HS Series

OM-USB-1208HS Series functions are illustrated in the block diagram shown here.

Figure 1. Functional block diagram

Software features

For information on the features of InstaCal and the other software included with your OM-USB-1208HS Series
hardware, refer to the OMB-DAQ-2400, OM-USB, OM-WEB, and OM-WLS Series Data Acquisition Software
User's Guide that shipped with the device.

6

Chapter 2

Installing a OM-USB-1208HS Series Device

What comes with your shipment?

Verify that the following hardware components are included in the shipment:

Hardware

 OM-USB-1208HS Series device — OM-USB-1208HS, OM-USB-1208HS-2AO, or

OM-USB-1208HS-4AO

 USB cable

Documentation

In addition to this hardware user's guide, the OMB-DAQ-2400, OM-USB, OM-WEB, and OM-WLS Series Data
Acquisition Software User's Guide booklet ships with the OM-USB-1208HS Series hardware. This booklet

provides an overview of the software you received with the device.

Unpacking

As 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.

If any components are missing or damaged, notify Omega Engineering immediately by phone, fax, or e-mail.

 Phone: [phone]
 Fax: [phone]
 Email: [e-mail]

Installing the software

Refer to the OMB-DAQ-2400, OM-USB, OM-WEB, and OM-WLS Series Data Acquisition Software User's
Guide for instructions on installing the software on the Software for OMB-DAQ-2400, OM-USB, OM-WEB, and
OM-WLS Series Data Acquisition Modules CD. This booklet is available in PDF at

http://www.omega.com/manuals/manualpdf/M4803.pdf.

Installing the hardware

Install the software before you install your hardware

The driver needed to run your board is installed with the software. Therefore, you need to install the software
before you install your hardware.

To connect a OM-USB-1208HS Series device to your system, turn on your computer and connect the USB
cable to an available USB port on the computer or to an external USB hub connected to the computer. Connect
the other end of the USB cable to the USB connector on the device. No external power is required.

When you connect the device for the first time, a Found New Hardware dialog opens when the operating
system detects the device. The dialog closes after the device is installed.

7

OM-USB-1208HS Series User's Guide Installing a OM-USB-1208HS Series Device

A green Status LED indicates the device status. When the LED is on, the device is powered and ready for
operation. When the LED is off, the device is not powered or did not initialize. Figure 2 on page 9 shows the
location of the Status LED.

Caution! Do not disconnect any device from the USB bus while the computer is communicating with a

OM-USB-1208HS Series device, or you may lose data and/or your ability to communicate with
the device.

If the Status LED is off

If the Status LED is on but then turns off, the computer has lost communication with the OM-USB-1208HS
Series device. To restore communication, disconnect the USB cable from the computer and then reconnect it.
This should restore communication, and the LED should turn on.

Calibrating a OM-USB-1208HS Series Device

OM-USB-1208HS Series devices are shipped fully calibrated. Calibration coefficients are stored in EEPROM.
Return the device to Omega Engineering when calibration is required. The normal calibration interval is once
per year.

8

1

Screw terminal pins 1 to 28

4

Activity LED

2

Screw terminal pins 29 to 56

5

USB connector

3

Status LED

Chapter 3

Functional Details

Analog input acquisition modes

OM-USB-1208HS Series devices acquire analog input data in two modes – software paced and hardware
paced.

Software paced mode

You acquire one analog sample at a time in software paced mode. You initiate the A/D conversion by calling a
software command. The analog value is converted to digital data and returned to the computer. You can repeat
this procedure until you have the total number of samples that you want.

The throughput sample rate in software paced mode is system-dependent, and can range from 33 S/s to
4000 S/s.

Hardware paced mode

You acquire data from up to eight channels in continuous scan mode. The analog data is continuously acquired,
converted to digital values, and written to an onboard FIFO buffer on the device until you stop the scan. The
FIFO buffer is serviced in blocks as the data is transferred from the device FIFO buffer to the memory buffer on
your computer.

The maximum sampling rate is 1 MS/s aggregate from one to eight channels. You can start a continuous scan
with either a software command or external hardware trigger event.

External components

OM-USB-1208HS Series hardware have the following external components, as shown in Figure 2.

 Screw terminals
 USB connector
 LEDs

Figure 2. OM-USB-1208HS Series components

9

OM-USB-1208HS Series User's Guide Functional Details

USB connector

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

LEDs

OM-USB-1208HS Series devices have two LEDs – 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 for the location of each LED.

Screw terminals

The device screw terminals provide the following connections:

 Eight analog input connections (AIN0 to AIN7)
 16 digital I/O connections (DI00 to DI015)
 Four analog output connections (AOUT0 to AOUT3)
 10 analog ground connections (AGND)
 Six digital ground connections (GND)
 One external clock input (AICKI) and one external clock output (AICKO) for analog inputs
 One external clock input (AOCKI) and one external clock output (AOCKO for analog outputs
 One digital trigger input (TRIG)
 Two counter inputs (CTR0, CTR1)
 One timer output (TMR)
 Two 5 V power output connections (+5 V)

Use 16 AWG to 30 AWG for signal connections. SE pinout locations are shown in Figure 3. Diff pinout
locations are shown in Figure 4.

Figure 3. SE mode pinout

* Pins 29 and 30 are "NC" on the OM-USB-1208HS. Pins 32 and 33 are "NC" on the OM-USB-1208HS and
OM-USB-1208HS-2AO.

10

OM-USB-1208HS Series User's Guide Functional Details

Figure 4. DIFF mode pinout

* Pins 29 and 30 are "NC" on the OM-USB-1208HS. Pins 32 and 33 are "NC" on the OM-USB-1208HS and
OM-USB-1208HS-2AO.

Signal connections

Analog input

You can configure the analog inputs for SE or DIFF mode.

With SE mode, connect up to eight inputs to screw terminals AIN0 to AIN7. Refer to Figure 3 on page 10 for the
location of these pins. SE mode requires two wires:

 Connect one wire to the signal you want to measure (AINx).
 Connect one wire to the analog ground reference (AGND).

In SE mode, the input voltage ranges are ±10 V, ±5 V, ±2.5 V, 0 to 10 V.

With DIFF mode, connect up to four DIFF inputs to screw terminals AIN0+/AIN0– to AIN3+/AIN3–. Refer to
Figure 4 for the location of these pins. DIFF mode requires two wires plus a ground reference:

 Connect one wire to the high/positive signal (AINx+).
 Connect one wire to the low/negative signal (AINx–).
 Connect one wire to the analog ground reference (AGND).

In DIFF mode, the input voltage ranges are ±20 V, ±10 V, and ±5 V. The voltage level on each AINx input is
limited to ±14 V.

For more information on analog signal connections

For more information on analog input connections, refer to the OMB-DAQ-2400, OM-USB, OM-WEB, and OM­WLS Series General Guide to Signal Connections (available on our web site at

www.omega.com/manuals/manualpdf/M4830.pdf).

11

OM-USB-1208HS Series User's Guide Functional Details

Analog output

You can connect up to four analog output connections to screw terminals AOUT0 to AOUT3. Refer to Figure 3
on page 10 for the location of these pins.

Each channel can be software-paced at rates up to 5,000 updates per second (system-dependent), or hardware­paced at rates up to 1 MS/s.

Each analog output on the OM-USB-1208HS-2AO and OM-USB-1208HS-2AO has a fixed ±10 V output
range. The outputs default to 0 V at power up.

External clock I/O

Use the AICKI and AOCKI terminals to receive a sampling clock from an external source.

Use the AICKO terminal to output the internal A/D sampling clock. Use the AOCKO terminal to output the
internal D/A sampling clock. When using an external clock, a pulse output generated by the external clock
rising edge is also available at these terminals.

Refer to Figure 3 on page 10 for the location of these pins.

Digital I/O

You can connect up to 16 digital I/O lines to screw terminals DIO0 through DIO15. Refer to Figure 3 on page 10
for the location of these pins.

The 16 DIO terminals have 47 k resistors that you can configure for pull-up/pull-down using a jumper inside the
case. The default configuration is pull-down.

You can use the digital I/O terminals to detect the state of any TTL-level input. Refer to the schematic shown in
Figure 5.

Figure 5. 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/pull-down capability

Each of the 16 DIO bits on the has a 47 kΩ pull-up/pull-down resistor. To configure these bits for either a +5 V
pull-up or a 0 V pull-down option, you must open the device case to access the three-pin jumper labeled W34.

The pull-up/pull-down voltage is common to all of the internal 47 kΩ resistors.

To open the case and set the W34 jumper, do the following.

1. Turn the device over and rest the top of the housing on a flat, stable surface.

2. Peel off the four rubber feet on the bottom of the device to access the screws.

12

OM-USB-1208HS Series User's Guide Functional Details

3. Remove the four screws from the bottom of the device.

4. Hold both the top and bottom sections together, turn the device over and rest it on the surface, then

carefully remove the top section of the case to expose the circuit board.

5. Configure jumper W34 for either pull-up or pull-down. The jumper is configured by default for pull-down

(see Figure 6 and Figure 7).

Figure 6. W34 jumper location (default pull-down setting shown)

Figure 7. W34 jumper – pull-down and pull-up configurations

6. Replace the top section of the case, and fasten it to the bottom section with the four screws. Replace the

rubber feet onto each screw.

For more information on digital signal connections

For more information on digital signal connections and digital I/O techniques, refer to the OMB-DAQ-2400,
OM-USB, OM-WEB, and OM-WLS Series General Guide to Signal Connections (available on our web site at

www.omega.com/manuals/manualpdf/M4830.pdf).

Counter I/O

The terminals provide connections to each 32-bit counter input channel (CTR0 and CTR1). Each counter can
count frequencies of up to 20 MHz. Refer to Figure 3 on page 10 for the location of these pins

Timer output

Use the TMR terminal to connect to the pulse width modulation (PWM) timer output.

You can set the following timer output parameters through software:

 pulse frequency
 duty cycle (pulse width divided by the pulse period)
 number of pulses to generate
 time delay before starting the timer output after it's enabled
 resting state of the output (idle high or idle low)

13

OM-USB-1208HS Series User's Guide Functional Details

The timer can generate a pulse output with a programmable frequency range of 0.00931 Hz up to 20 MHz.

Both the period and time delay ranges are 50 ns to 107.4 seconds. Figure 8 shows the timer output schematic.

Figure 8. PWM timer output schematic

Refer to Figure 3 on page 10 for the location of the TMR pin.

Trigger input

The TRIG connection is an external digital trigger input. The trigger mode is software-selectable for:

 Level-sensitive or edge-sensitive
 Rising or falling edge
 High or low level

The default setting at power up is edge sensitive, rising edge.

Refer to Figure 3 on page 10 for the location of the TRIG pin.

Retrigger

The acquisition uses the trigger settings for positive edge/negative edge and level-sensitive/edge-sensitive, but
automatically re-arms the trigger after it is activated

Power outputs

You can use the two +5V connections to supply power to external devices or circuitry. These terminals can
output up to 285 mA.

Caution! The +5V terminals are outputs. Do not connect to an external power supply or you may damage

the device and possibly the computer.

Ground

The analog ground (AGND) terminals provide a common ground for all analog channels.

The ground (GND) terminals provide a common ground for the digital, counter, timer, and clock channels and
the power terminals.

Refer to Figure 3 on page 10 for the location of the AGND and GND pins.

14

Parameter

Condition

Specification

A/D converter

Analog Devices AD7329
13-bit successive approximation type

Input ranges

Software-selectable
per channel

 DIFF: ±20 V, ±10 V, ±5 V (The voltage level on each

individual AIN input is limited to ±14 V.)

 SE: ±10 V, ±5 V, ±2.5 V, 0 V to 10 V

Number of channels

4 DIFF, 8 SE
Software-selectable

Input configuration

Multiplexed

Channel gain queue

8 unique consecutive elements

Software-selectable range for each channel

Absolute maximum input
voltage

CHx IN to GND

±25 V max (power on)
±12 V max (power off)

Input impedance

35 MΩ min

Input bandwidth (–3 dB)

All input ranges

2 MHz typ

Input leakage current

±250 nA typ

Input capacitance

32 pf typ

Offset error drift

5 ppm/°C typ

Gain error drift

25 ppm/°C typ

Maximum working voltage
(signal + common mode)

±20 V

±14 V

±10 V

±11 V

±5 V

±5.5 V

Sampling rate

1 S/s to 1 MS/s, software-selectable

Sample clock source

Internal A/D clock or AICKI

Burst mode

Software-selectable, burst rate = 1µs

Throughput

Software paced

33 S/s to 4000 S/s typ, system dependent

Scan to PC memory

1 MS/s max

Resolution

13 bits

A/D no missing codes
(uncalibrated)

DIFF mode

13 bits

SE mode

12 bits

CMRR

60hz

74 dB typ

Crosstalk

SE mode, all ranges, 250 kHz
input signal

–62 dB typ

DIFF mode, all ranges,
250 kHz input signal

–78 dB typ

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. Analog input specifications

Chapter 4

OM-USB-1208HS Series User's Guide Specifications

Range

Accuracy (mV)

±20 V (DIFF mode)

±9.55 typ, ±13.18 max

±10 V (DIFF mode)

±4.59 typ, ±6.23 max

±5 V (DIFF mode)

±2.25 typ, ±2.75 max

±10 V (SE mode)

±5.10 typ, ±8.06 max

±5 V (SE mode)

±2.63 typ, ±4.03 max

±2.5 V (SE mode)

±1.59 typ, ±2.70 max

0 – 10 V (SE mode)

±3.29 typ, ±5.13 max

Range

Typical counts

LSBrms

±20 V (DIFF mode)

3

0.45

±10 V (DIFF mode)

3

0.45

±5 V (DIFF mode)

3

0.45

±10 V (SE mode)

5

0.91

±5 V (SE mode)

5

0.91

±2.5 V (SE mode)

5

0.91

0 – 10 V (SE mode)

5

0.91

Condition

Range

±1 LSB

±4 LSB

±8 LSB

+ full-scale to –full-scale
channel switch, same range
to same range

±10 V

1.5

1.1

1.0

±5 V

2.1

1.1

1.0

±2.5 V

2.2

1.1

1.0

0 V to 10 V

2.6

1.1

1.0

Table 2. Calibrated absolute accuracy

Table 3 summarizes the noise performance for OM-USB-1208HS Series hardware. Noise distribution is

determined by gathering 50 kS with inputs tied to ground at the user connector. Samples are gathered at the
maximum specified sampling rate of 1 MS/s.

Table 3. Noise performance

Table 4. Input settling time in µs, typical

16

OM-USB-1208HS Series User's Guide Specifications

Parameter

Condition

Specification

D/A converter

Texas Instruments DAC7553

Number of channels

OM-USB-1208HS-2AO: 2 independent
OM-USB-1208HS-4AO: 4 independent

Resolution

12 bits

Output range

Calibrated

±10 V

Uncalibrated

±10.2 V

Output transient

Host PC is reset, powered on, suspended,
or a reset command is issued to device.

Duration: 3 ms typ
Amplitude: 6 V p-p typ

D/A update rate

Software paced

33 to 5000 S/s typ, system dependent

Hardware paced

1 MHz max (per channel)

Sample clock source

Internal D/A clock or AOCKI

Monotonicity

12 bits

Output current

±3 mA max per channel

Output short-circuit
protection

Output connect to GND

Unlimited duration (10 mA typ)
Output coupling

DC

Power up and reset state

0 V

Output noise

0.53 mV rms

Settling time (to 0.05%)

20 V output step, (RL=5 kΩ, CL=200 pf)

5 µS max

Absolute accuracy

±0.1%

Slew rate

6.7 V/µs typ

Offset error drift

10 ppm/°C typ

Gain error drift

65 ppm/°C typ

Digital type

CMOS

Number of I/O

16

Configuration

Each bit may be configured as input (power on default) or output

Pull-up configuration

The port has 47 kΩ resistors configurable as pull-up or pull-down with an internal
jumper. The default setting is pull-down.

Digital I/O transfer rate
(system-paced)

33 to 8000 port reads/writes or single bit reads/writes per second typ, system dependent.

Input high voltage

2.0 V min

5.5 V absolute max

Input low voltage

0.8 V max
–0.5 V absolute min
0 V recommended min

Output high voltage

4.4 V min (IOH = –50 µA)

3.76 V min (IOH = –24 mA)

Output low voltage

0.1 V max (IOL = 50 µA)

0.44 V max (IOL = 24 mA)

Output current

±24 mA max per terminal (see "Power"section for additional information)

Analog output (OM-USB-1208HS-2AO, OM-USB-1208HS-4AO)

Table 5. Analog output specifications

Digital input/output

Table 6. Digital I/O specifications

17

OM-USB-1208HS Series User's Guide Specifications

Parameter

Specification

Trigger source

TRIG input

Trigger mode

Software-selectable for edge or level sensitive, rising or falling edge, high or low level.
Power on default is edge sensitive, rising edge.

Trigger latency

1 µs + 1 clock cycle max

Trigger pulse width

100 ns min

Input type

Schmitt Trigger, 33 Ω series resistor and 47 kΩ pull-down to ground

Schmitt trigger hysteresis

0.4 V to 1.2 V

Input high voltage

2.2 V min

5.5 V absolute max

Input low voltage

1.5 V max
–0.5 V absolute min
0 V recommended min

Parameter

Specification

Terminal names

OM-USB-1208HS: AICKI, AICKO
OM-USB-1208HS-2AO: AICKI, AICKO, AOCKI, AOCKO
OM-USB-1208HS-4AO: AICKI, AICKO, AOCKI, AOCKO

Terminal types

AxCKI: Input, active on rising edge
AxCKO: Output, power on default is 0 V, active on rising edge

Terminal descriptions

AxCKI: Receives sampling clock from external source
AxCKO: Outputs the internal sampling clock (D/A or A/D clock or D/A clock, if

supported) or pulse generated from AxCKI when in external clock
mode

Input clock rate

1 MHz max

Clock pulse width

AxCKI: 400 ns min
AxCKO: 400 ns min

Input type

Schmitt trigger, 33 Ω series resistor, 47 kΩ pull-down to ground

Schmitt trigger hysteresis

0.4 V to 1.2 V

Input high voltage

2.2 V min

5.5 V absolute max

Input low voltage

1.5 V max
–0.5 V absolute min
0 V recommended min

Output high voltage

4.4 V min (IOH = –50 µA)

3.76 V min (IOH = –24 mA)

Output low voltage

0.1 V max (IOL = 50 µA)

0.44 V max (IOL = 24 mA)

Output current

±24 mA max per terminal (see "Power" section for additional information)

External trigger

Table 7. External trigger specifications

External clock input/output

Table 8. External clock I/O specifications

18

OM-USB-1208HS Series User's Guide Specifications

Parameter

Specification

Counter terminal names

CTR0, CTR1

Counter type

Event counter

Number of channels

2

Input type

Schmitt trigger, 33 Ω series resistor, 47 kΩ pull-down to ground

Schmitt trigger hysteresis

0.4 V to 1.2 V

Input high voltage

2.2 V min

5.5 V absolute max

Input low voltage

1.5 V max
–0.5 V absolute min
0 V recommended min

Resolution

32 bits

Maximum input frequency

20 MHz

Counter read/write rates
(software paced)

33 to 8000 reads/writes per second typ, system dependent

High pulse width

25 ns min

Low pulse width

25 ns min

Parameter

Specification

Timer terminal name

TMR

Timer type

PWM output with count, period, delay, and pulse width registers

Output value

Default state is idle low with pulses high, software-selectable output invert

Internal clock frequency

40 MHz

Register widths

32 bits

High pulse width

20 ns min

Low pulse width

20 ns min

Output high voltage

4.4 V min (IOH = –50 µA)

3.76 V min (IOH = –24 mA)

Output low voltage

0.1 V max (IOL = 50 µA)

0.44 V max (IOL = 24 mA)

Output current

±24 mA max per pin (see "Power" section for additional information)

Parameter

Specification

Data FIFO

OM-USB-1208HS: 4 kS analog input
OM-USB-1208HS-2AO: 4 kS analog input/4 kS analog output
OM-USB-1208HS-4AO: 4 kS analog input/4 kS analog output

Non-volatile memory

32 KB (16 KB firmware storage, 16 KB calibration/user data)

Counters

Table 9. Counter specifications

Timer

Memory

Table 10. Timer specifications

Table 11. Memory specifications

19

OM-USB-1208HS Series User's Guide Specifications

Parameter

Condition

Specification

Operating modes

Bus-powered, USB 5 V supply

Supply current (see Note 1)

Suspend mode

<2.5 mA

Enumeration

<100 mA

Run mode

<500 mA

Power consumption
excluding analog and digital
outputs

Run mode

OM-USB-1208HS: 1.05 W max (210 mA input current)
OM-USB-1208HS-2AO: 1.125 W max (225 mA input current)
OM-USB-1208HS-4AO: 1.175 W max (235 mA input current)

Power available for +5 V,
AICKO, AOCKO, TMR,
analog outputs, and
digital I/O

Run mode

OM-USB-1208HS: 1.45 W max
OM-USB-1208HS-2AO: 1.375 W max
OM-USB-1208HS-4AO: 1.325 W max
The total power consumption for all external loads must be less than this

value, and each load must meet the individual specification for the
terminal.

Digital output power
calculation

Power per output = Iout × 5 V
(for example, @ 24 mA, P = 0.024 × 5 = 120 mW / output)

Analog output power
calculation
(OM-USB-1208HS-2AO/
OM-USB-1208HS-4AO)

Power per output = (Iout × 16.5 V) / 0.78
(for example, @ 3 mA, P = (0.003 × 16.5) / 0.78 = 63.5 mW/output)
+5 V output power
calculation

Power (W) = Iout × 5 V

+5 V output voltage range
(see Note 2)

Run mode

4.5 V min, 5.25 V max

Suspend mode,
enumeration

0 V

+5 V output current

Run mode, no
other output
loads

OM-USB-1208HS: 290 mA max (1.45 W)
OM-USB-1208HS-2AO: 275 mA max (1.375 W)
OM-USB-1208HS-4AO: 265 mA max (1.325 W)

Fuses

On USB
supply

0452.750 - Littelfuse 0.750A NANO2® Slo-Blo® Subminiature Surface

Mount Fuse.
Spare fuse mounted in holder on PCB.

Parameter

Specification

USB device type

USB 2.0 (high-speed)

USB device compatibility

USB 1.1, 2.0

USB cable length

3 meters max

USB cable type

A-B cable, UL type AWM 2527 or equivalent (min 24 AWG VBUS/GND, min 28 AWG
D+/D–).

Power

Table 12. Power specifications

Note 1: This is the total current consumption for OM-USB-1208HS Series hardware, including +5 V, digital

output and analog output currents (if supported).

Note 2: Output voltage range assumes input power is within specified limits.

USB specifications

Table 13. USB specifications

20

OM-USB-1208HS Series User's Guide Specifications

Parameter

Specification

Operating temperature range

0 °C to 50 °C

Storage temperature range

–40 °C to 85 °C

Humidity

0% to 90% non-condensing

Parameter

Specification

Dimensions

127 × 89.9 × 35.6 mm (5.00 × 3.53 × 1.40 in.)

Parameter

Specification

Connector type

Screw terminal

Wire gauge range

16 AWG to 30 AWG

Environmental

Table 14. Environmental specifications

Mechanical

Table 15. Mechanical specifications

Main connector and pinout

Table 16. Main connector specifications

21

OM-USB-1208HS Series User's Guide Specifications

Pin

Signal name

Pin

Signal name

1

AIN0

29

AOUT01

2

AGND

30

AOUT11

3

AIN1

31

AGND

4

AGND

32

AOUT22

5

AIN2

33

AOUT32

6

AGND

34

AGND

7

AIN3

35

AICKI

8

AGND

36

AICKO

9

AIN4

37

AOCKI3

10

AGND

38

AOCKO3

11

AIN5

39

TRIG

12

AGND

40

GND

13

AIN6

41

CTR0

14

AGND

42

CTR1

15

AIN7

43

TMR

16

AGND

44

GND

17

empty

45

empty

18

+5V

46

+5V

19

GND

47

GND

20

DIO0

48

DIO8

21

DIO1

49

DIO9

22

DIO2

50

DIO10

23

DIO3

51

DIO11

24

DIO4

52

DIO12

25

DIO5

53

DIO13

26

DIO6

54

DIO14

27

DIO7

55

DIO15

28

GND

56

GND

Table 17. Main connector single-ended pinout

1

OM-USB-1208HS-2AO and OM-USB-1208HS-4AO only; NC (no connection) on the OM-USB-1208HS.

2

OM-USB-1208HS-4AO only; NC (no connection) on the OM-USB-1208HS AND OM-USB-1208HS-2AO.

3

OM-USB-1208HS-2AO and OM-USB-1208HS-4AO only; NC (no connection) on the OM-USB-1208HS.

22

OM-USB-1208HS Series User's Guide Specifications

Pin

Signal name

Pin

Signal name

1

AIN0 +

29

AOUT01

2

AGND

30

AOUT11

3

AIN0 -

31

AGND

4

AGND

32

AOUT22

5

AIN1 +

33

AOUT32

6

AGND

34

AGND

7

AIN1 -

35

AICKI

8

AGND

36

AICKO

9

AIN2 +

37

AOCKI3

10

AGND

38

AOCKO3

11

AIN2 -

39

TRIG

12

AGND

40

GND

13

AIN3 +

41

CTR0

14

AGND

42

CTR1

15

AIN3 -

43

TMR

16

AGND

44

GND

17

empty

45

empty

18

+5V

46

+5V

19

GND

47

GND

20

DIO0

48

DIO8

21

DIO1

49

DIO9

22

DIO2

50

DIO10

23

DIO3

51

DIO11

24

DIO4

52

DIO12

25

DIO5

53

DIO13

26

DIO6

54

DIO14

27

DIO7

55

DIO15

28

GND

56

GND

Table 18. Main connector differential pinout

1

OM-USB-1208HS-2AO and OM-USB-1208HS-4AO only; NC (no connection) on the OM-USB-1208HS.

2

OM-USB-1208HS-4AO only; NC (no connection) on the OM-USB-1208HS AND OM-USB-1208HS-2AO.

3

OM-USB-1208HS-2AO and OM-USB-1208HS-4AO only; NC (no connection) on the OM-USB-1208HS.

23

WARRANTY/DISCLAIMER

OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a
period of 13 months from date of purchase. OMEGA’s WARRANTY adds an additional one (1) month
grace period to the normal one (1) year product warranty to cover handling and shipping time. This
ensures that OMEGA’s customers receive maximum coverage on each product.

If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer Service
Department will issue an Authorized Return (AR) number immediately upon phone or written request.
Upon examination by OMEGA, if the unit is found to be defective, it will be repaired or replaced at no
charge. OMEGA’s WARRANTY does not apply to defects resulting from any action of the purchaser,
including but not limited to mishandling, improper interfacing, operation outside of design limits,
improper repair, or unauthorized modification. This WARRANTY is VOID if the unit shows evidence of
having been tampered with or shows evidence of having been damaged as a result of excessive corrosion;
or current, heat, moisture or vibration; improper specification; misapplication; misuse or other operating
conditions outside of OMEGA’s control. Components in which wear is not warranted, include but are not
limited to contact points, fuses, and triacs.

OMEGA is pleased to offer suggestions on the use of its various products. However,
OMEGA neither assumes responsibility for any omissions or errors nor assumes liability for any
damages that result from the use of its products in accordance with information provided by
OMEGA, either verbal or written. OMEGA warrants only that the parts manufactured by the
company will be as specified and free of defects. OMEGA MAKES NO OTHER WARRANTIES OR
REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESSED OR IMPLIED, EXCEPT THAT OF
TITLE, AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. LIMITATION OF
LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total liability of
OMEGA with respect to this order, whether based on contract, warranty, negligence,
indemnification, strict liability or otherwise, shall not exceed the purchase price of the
component upon which liability is based. In no event shall OMEGA be liable for
consequential, incidental or special damages.

CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a “Basic
Component” under 10 CFR 21 (NRC), used in or with any nuclear installation or activity; or (2) in medical
applications or used on humans. Should any Product(s) be used in or with any nuclear installation or
activity, medical application, used on humans, or misused in any way, OMEGA assumes no responsibility
as set forth in our basic WARRANTY/DISCLAIMER language, and, additionally, purchaser will indemnify
OMEGA and hold OMEGA harmless from any liability or damage whatsoever arising out of the use of the
Product(s) in such a manner.

RETURN REQUESTS/INQUIRIES

Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department. BEFORE
RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST OBTAIN AN AUTHORIZED RETURN
(AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID
PROCESSING DELAYS). The assigned AR number should then be marked on the outside of the return
package and on any correspondence.

The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent
breakage in transit.

FOR WARRANTY

RETURNS, please have the
following information available BEFORE
contacting OMEGA:

1. Purchase Order number under which the product

was PURCHASED,

2. Model and serial number of the product under

warranty, and

3. Repair instructions and/or specific problems

relative to the product.

FOR NON-WARRANTY REPAIRS,

consult OMEGA
for current repair charges. Have the following
information available BEFORE contacting OMEGA:

1. Purchase Order number to cover the COST

of the repair,

2. Model and serial number of the product, and

3. Repair instructions and/or specific problems

relative to the product.

OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible. This affords
our customers the latest in technology and engineering.

OMEGA is a registered trademark of OMEGA ENGINEERING, INC.
© Copyright 2011 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied,

reproduced, translated, or reduced to any electronic medium or machine-readable form, in whole or in part, without the
prior written consent of OMEGA ENGINEERING, INC.

M5047/0711

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