Omega OM-USB-1208HS Series User manual

Servicing North America:
U.S.A.: Omega Engineering, Inc., One Omega Drive, P.O. Box 4047
Stamford, CT 06907-0047 USA
Toll-Free: 1-800-826-6342 (USA & Canada only)
Customer Service: 1-800-622-2378 (USA & Canada only)
Engineering Service: 1-800-872-9436 (USA & Canada only)
Tel: [phone] Fax: [phone]
e-mail: [email protected]
For Other Locations Visit omega.com/worldwide
omega.com [email protected]
The information contained in this document is believed to be correct, but OMEGA accepts no liability for any errors it contains, and reserves
the right to alter specifications without notice.
WARNING: These products are not designed for use in, and should not be used for, human applications.

3
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 OM-USB-1208HS Series ............................................................................................6
Software features................................................................................................................................................7
Chapter 2
Installing a OM-USB-1208HS Series Device.......................................................................................8
What comes with your shipment?.......................................................................................................................8
Hardware .......................................................................................................................................................................... 8
Documentation.................................................................................................................................................................. 8
Unpacking...........................................................................................................................................................8
Installing the software ........................................................................................................................................8
Installing the hardware .......................................................................................................................................8
Calibrating a OM-USB-1208HS Series Device..................................................................................................9
Chapter 3
Functional Details ...............................................................................................................................10
Analog input acquisition modes .......................................................................................................................10
Software paced mode.......................................................................................................................................................10
Hardware paced mode......................................................................................................................................................10
External components ........................................................................................................................................10
USB connector.................................................................................................................................................................10
LEDs................................................................................................................................................................................10
Screw terminals................................................................................................................................................................11
Signal connections............................................................................................................................................12
Analog input ....................................................................................................................................................................12
Analog output ..................................................................................................................................................................12
External clock I/O............................................................................................................................................................13
Digital I/O........................................................................................................................................................................13
Counter I/O......................................................................................................................................................................14
Timer output ....................................................................................................................................................................14
Trigger input....................................................................................................................................................................15
Power outputs ..................................................................................................................................................................15
Ground.............................................................................................................................................................................15
Chapter 4
Specifications......................................................................................................................................16
Analog input.....................................................................................................................................................16
Analog output (OM-USB-1208HS-2AO, OM-USB-1208HS-4AO)................................................................18
Digital input/output...........................................................................................................................................18
External trigger.................................................................................................................................................19
External clock input/output...............................................................................................................................19
Counters............................................................................................................................................................20
Timer ................................................................................................................................................................20
Memory ............................................................................................................................................................20
Power................................................................................................................................................................21
USB specifications ...........................................................................................................................................21
Environmental ..................................................................................................................................................22

OM-USB-1208HS Series User's Guide
4
Mechanical .......................................................................................................................................................22
Screw terminal connector and pinout ...............................................................................................................22

5
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]m

6
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.

OM-USB-1208HS Series User's Guide Introducing the OM-USB-1208HS Series
7
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.

8
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.
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 10 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.

OM-USB-1208HS Series User's Guide Installing a OM-USB-1208HS Series Device
9
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.

10
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
1
Screw terminal pins 1 to 28
4
Activity LED
2
Screw terminal pins 29 to 56
5
USB connector
3
Status LED
Figure 2. OM-USB-1208HS Series components
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.

OM-USB-1208HS Series User's Guide Functional Details
11
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.

OM-USB-1208HS Series User's Guide Functional Details
12
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 11 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 OM-
WLS Series General Guide to Signal Connections (available on our web site at
www.omega.com/manuals/manualpdf/M4830.pdf).
Analog output
You can connect up to four analog output connections to screw terminals AOUT0 to AOUT3. Refer to Figure 3
on page 11 for the location of these pins.

OM-USB-1208HS Series User's Guide Functional Details
13
Each channel can be software-paced at rates up to 5,000 updates per second (system-dependent), or hardware-
paced 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 11 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 11
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.
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).

OM-USB-1208HS Series User's Guide Functional Details
14
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 11 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)
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.

OM-USB-1208HS Series User's Guide Functional Details
15
Figure 8. PWM timer output schematic
Refer to Figure 3 on page 11 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 11 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 11 for the location of the AGND and GND pins.

16
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. Analog input specifications
Parameter
Condition
Specification
A/D converter
Analog Devices AD7329
13-bit successive approximation type
Input ranges
Software-selectable
per channel
Differential: ±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 differential, 8 single-ended
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 programmable
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)
Differential mode
13 bits
Single-ended mode
12 bits
CMRR
60hz
74 dB typ
Crosstalk
SE mode, all ranges, 250 kHz
input signal
–62 dB typ
Differential mode, all ranges,
250 kHz input signal
–78 dB typ

OM-USB-1208HS Series User's Guide Specifications
17
Table 2. Calibrated absolute accuracy
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
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
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
Table 4. Input settling time in µs, typical
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

OM-USB-1208HS Series User's Guide Specifications
18
Analog output (OM-USB-1208HS-2AO, OM-USB-1208HS-4AO)
Table 5. Analog output 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 input/output
Table 6. Digital I/O specifications
Parameter
Specification
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)

OM-USB-1208HS Series User's Guide Specifications
19
External trigger
Table 7. External trigger 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
External clock input/output
Table 8. External clock I/O specifications
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)

OM-USB-1208HS Series User's Guide Specifications
20
Counters
Table 9. Counter 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
Timer
Table 10. Timer specifications
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)
Memory
Table 11. Memory specifications
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)