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PCIe-IDIO Series

PCI Express Optically Isolated Digital I/O Cards with Change of State Detection


  • 24 optically isolated, non-polarized digital inputs
  • Software configurable filters on inputs for electrically noisy environments
  • Can detect input state change and assert interrupt
  • 24 optically isolated high-side FET switches
  • Opto-couplers rated for 2.5kV isolation
  • Four optically isolated output groups and two optically isolated input groups
  • 8 non-isolated TTL/CMOS I/O lines
  • Designed, made, supported, and manufactured in the USA


  • Extended temperature operation (-40°C to +85°C)
  • 12-channel version (with 4 TTL I/O) available
  • Input only and output only versions available
  • RoHS compliant version
  • Support for Wind River VxWorks (call for ordering information)

This product is a x1 lane PCIe isolated digital input and FET output board with Change of State (COS) detection capabilities. In addition to the isolated signals, 8 (or 4) TTL/CMOS input/output pins are available, for your application’s convenience.

The isolated inputs can be driven by either AC or DC and are not polarity sensitive. Input signals are rectified by a diode bridge and applied to the inputs of opto-isolators. A 1.8k ohm resistor in series provides current limiting. Standard 12/24 AC control transmitter outputs can be accepted as well as DC voltages. The input voltage range is 3V to 31VDC (or 40-10kHz RMS). To extend the input voltage range, you may connect external resistors in series. Inputs can be configured to generate an IRQ when the input changes from active-to-inactive, inactive-to-active, or both in groups of eight bits.

The PCIe-IDIO-24 features fully protected and isolated high side power MOSFET switch outputs which are de-energized at power-up to prevent an unintended control output signal. They are capable of switching customer supplied voltages of 5 to 34VDC, at up to 2A.

The card is 6.6 inches in length and 4.2 inches seated height. I/O wiring connections for this board are via a 78-pin D-sub connector. A molded round-wire “Y” cable is typically used to connect this card to termination panels with two 37-pin D-sub connectors.


The PCIe-IDIO Series is excellent for use in a multitude of applications requiring digital control or monitoring such as in test equipment, instrumentation, lab automation, and process control. The board is capable of monitoring electrical devices such as motor controllers, powered switches, dry contacts, thermostats, limit switches, push buttons etc.. The PCIe-IDIO Series can be used in the following markets.

  • Process Monitoring
  • Manufacturing/Production Test
  • Machine Control
  • Monitoring and Control
  • Security Systems, Energy Management
  • Industrial Automation
  • Factory Automation
  • Laboratory Automation
  • Embedded OEM

Accessories and Connections

For the PCIe-IDIO Series, I/O is accessed via a 78 pin DB female connector on the mounting bracket of the card. A molded breakout cable (model CAB78-37/2) is optionally available that divides the 78 pins into two DB37F connectors. Also available is a kit (model STB-37/2 Kit) which includes the cable, two STB-37 screw terminal boards, and one-foot length of DIN-rail mountable SNAPTRACK to mount the screw terminal boards.


The card is supported for use in most operating systems and includes a free DOS, Linux, and Windows XP -> 10, both 32 & 64 bit compatible software package. This package contains sample programs and source code in Visual Basic, Delphi, and Visual C++ for Windows. Also provided is a graphical setup program in Windows. Linux support includes installation files and basic samples for programming from user level via an open source kernel driver. Third party support includes a Windows standard DLL interface usable from the most popular application programs, and includes LabVIEW 8.5+ VIs. Embedded OS support includes Windows Xpe, WES7, vxWorks, etc.

Available Reference Manuals

Available Software Downloads

Available Datasheets

Drivers and Downloads

Full list of available Downloads: Software Packages, Drivers, Manuals, and other documents

Custom Software

ACCES also offers Custom Software Services for our products. Our prices are unbelievably low, often as inexpensive as free! If you need something tweaked to support your needs, or an entire enterprise application developed from scratch, it is definitely worth your time to inquire with us, first.

Further information about available ACCES Software:

Redistributing Windows Drivers
A list of ACCES drivers and the files that compose them under different versions of Windows, so you can easily redistribute ACCES cards and drivers.


ACCES has successfully partnered with Wind River to bring our entire line of PCI and PCI Express DAQ cards to VxWorks 7!

VxWorks 7 VxBus Gen 2 drivers, with easy-to-use API-libraries, are available for this product, including full source and sample code.

Designed to be compatible with our AIOWDM.dll Windows driver & API, this kernel module adds zero% CPU-cycle overhead to your VxWorks runtimes while allowing the lowest-latency hardware register access possible.

You can find more information about our VxWorks libraries and services on our Wind River Silver Partner page.

Isolated Digital Inputs

  • Number of inputs: 24
  • Type: Non-polarized, optically isolated sharing a common return per 12 channel group (not TTL/CMOS compatible)
  • Voltage Range: 3 to 31V DC or 22 VACrms (40-10kHz)
  • Isolation: Opto-couplers rated at 2.5kV (see manual)
  • Input Resistance: 1.8k ohms in series with two diodes and a photo-coupler LED
  • Response Time: with filter: 4.7 mSec without filter: rise time = 10 uSec fall time = 30 uSec
  • Interrupts: Change of State Detection available on all 32 input bits; software enabled in 8 bit groups; byte-wide pattern recognition

Non Isolated Digital Inputs/Outputs

  • Number of lines: 8, programmable as all ins or all outs
  • Type: TTL/CMOS compatible, pulled up to 5V via 10k ohms

Solid State FET Outputs

  • Number of outputs: 24, Isolated in four, 6-channel groups
  • Output Type: Smart High Side Power MOSFET, Fully Protected (short circuit, over-temp., ESD, inductive flyback)
  • Voltage Range: 5-34VDC recommended (40VDC absolute maximum)
  • FET Ratings: On-state resistance = 60mΩ 2A continuous per FET, with a 9A cumulative total per group of 6 FETs


  • Operating Temperature: Commercial 0°C to 70°C, Industrial -40°C to +85°C
  • Storage Temperature: -40°C to +85°C
  • Humidity: 5% to 95%, (non-condensing)
  • Card Dimensions: Standard Height 4.2" (106.65 mm), half length 6.6" (167.6 mm) long
  • Connector: DB78 Female Mating Connector: AMPLIMITE 1658674-1 or equivalent


  • Call

Regulatory Compliance

  • This product is designed to be in full compliance with CE requirements.

OEM and volume pricing available, please call us.  

ModelPrice (USD)

PCIe-IDIO-24PCI Express card with 24 isolated digital inputs and 24 isolated high-side FET switch outputs
PCIe-IDIO-12PCI Express card with 12 isolated digital inputs and 12 isolated high-side FET switch outputs
PCIe-IDI-24PCI Express card with 24 optically isolated digital inputs only
PCIe-IDO-24PCI Express card with 24 isolated high-side FET switch outputs only
STB-37/2 KITScrew terminal and cabling solution includes two STB-37 screw terminal cards, Y Cable, and 1' SNAPTRACK $159
STB-37/2 KIT-CLAs above except includes four clips for mounting the STB-37/2 Kit to a standard DIN-Rail $178
CAB78-37/26' round-wire "Y" cable which connects to the DB-78 connector and terminates to two DB-37 female connectors $80
CAB78-37/1For use with PCIe-IDIO-12. 6' round-wire cable which connects to the DB-78 connector and terminates to a single DB-37 female connector $50
STB-37/1 KITFor use with PCIe-IDIO-12. Screw terminal and cabling solution includes one STB-37 screw terminal card, Cable, and 1' SNAPTRACK $95
STB-37/1 KIT-CLFor use with PCIe-IDIO-12. As above except includes four clips for mounting the STB-37/1 Kit to a standard DIN-Rail $call
STB-37DIN-rail mountable screw terminal board for use with any ACCES card that has a 37 pin mating connector $39
DIN-SNAPOne foot length SNAPTRACK with four clips, for mounting two STB-XX screw terminal boards on a DIN rail $20
DIN-SNAP-6Six inch length SNAPTRACK with two clips, for mounting one STB-XX screw terminal board on a DIN rail $15
SNAPTRACKOne foot length of SNAPTRACK mounting rail for two STB-XX products $10
SNAPTRACK-6Six inch length of SNAPTRACK mounting rail for one STB-XX product $6
Model Options:
-TExtended temperature (-40°C to +85°C)
-RoHSRoHS compliant version

Acquisition, Control, Communication: Engineering and Systems