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PCIe-DIO Family 24 and 48 Digital Input/Output Cards

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


  • 48 or 24 channel high-current TTL digital I/O lines
  • Change of State (COS) detection and interrupt capabilities
  • Compatible with industry standard 8255 PPI
  • Two 50-pin male headers with 24 digital lines each
  • User interrupt pin on each DIO connector
  • All 48 digital I/O lines buffered with 32mA source / 64mA sink current capabilities
  • Four and eight bit ports independently selectable for inputs or outputs
  • Pull-ups on DIO lines (optional pull-down)
  • 5V VCCIO (3.3V optional)
  • VCCIO available to the user on each I/O header
  • Compatible with industry standard I/O racks like Grayhill, Opto 22, Western Reserve Controls, etc.
  • Easy upgrade from PCI-DIO-48S
  • Designed, made, supported, and manufactured in the USA


  • 3.3V VCCIO (LVTTL)
  • Molex PC-style connector for maximum 5V VCCIO current sourcing capability
  • RoHS compliant version
  • Extended temperature operation (-40°C to +85°C)
  • Support for Wind River VxWorks (call for ordering information)

The PCIe-DIO-48S is a 48 channel PCI Express (PCIe) card designed for use in a variety of digital I/O applications. It uses the high speed PCI Express bus to transfer digital data to and from the card. The digital I/O is compatible with 8255 PPI (mode 0), making it easy to program. This also allows for simple and trouble-free migration from other ACCES PCI digital I/O cards. The card features a x1 lane PCI Express connector which can be used in any available x1, x2, x4, x8, x12, or x16 PCI Express expansion slot.

Each 50-pin header has three 8-bit I/O ports designated A, B and C. Port C can be further divided into two 4-bit nibbles. Each port can be programmed as inputs or outputs. Change of State (COS) detection and interrupt capabilities are designed to relieve software from polling routines that can consume valuable processing time. Each port can be programmed for detecting state changes on their lines, in which any changes of the enabled port's bits (low-to-high or high-to-low) will generate an IRQ. An ISR (interrupt service routine) then polls the port to determine which bit changed state and clear the interrupt. The connectors are also compatible with existing 48 and 24 channel ACCES PCI digital I/O cards.

The card is 6.6 inches in length and 4.2 inches seated height. One or two flat ribbon cables are routed through a cutout in the mounting bracket and plugged onto the keyed 50-pin male headers on the side of the card. A strain relief bracket securely holds the ribbon cables at the point of exit via the PCIe mounting bracket.


The PCIe-DIO-48S 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-DIO-48S 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


Available accessories include a broad range of ribbon cables, screw terminal boards and optically isolated adapters and DIN-rail mounts for a variety of quick and easy connectivity options. Use ribbon cables with a female header on one end and a 50-pin female edge connector on the other to connect with industry standard solid state module racks.


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.

Digital Signaling

  • VCCIO 5V (TTL), optional 3.3V (LVTTL) on 50 pin header

Digital Inputs

  • Logic High 2.0V to VCCIO
  • Logic Low 0V to 0.8V
  • Current 20uA (max)

Digital Ouputs

  • Logic High 2.0V (min); 32mA source
  • Logic Low 0.55V (max); 64mA sink
  • Power Output VCCIO (P2 & P3; pin 49) Via 0.5A resettable fuse


  • Operating Temperature: Commercial 0° to 70°C; Industrial -40° to +85°C
  • Storage Temperature: -55° to +150° C
  • Humidity: 5% to 95%, non-condensing.
  • Card Dimensions: 4.72" (120mm) long by 4.20" (106.7mm) high


  • Call

Regulatory Compliance

  • This product is in full compliance with CE requirements.

OEM and volume pricing available, please call us.  

ModelPrice (USD)

PCIe-DIO-48SPCI Express 48 channel digital I/O card with change of state detection
PCIe-DIO-48PCI Express 48 channel digital I/O card without change of state detection
PCIe-DIO-24SPCI Express 24 channel digital I/O card with change of state detection
STB-50DIN-rail mountable screw terminal board for 50 pin header type connector $44
CAB50F-650 pin ribbon cable with female header connectors, 6 feet long $30
STB-48CH48 digital I/O single screw terminal board $149
IIB-2424 channel optical isolater board for each 50 pin header $149
ROB-2424 channel electromechanical relay card for each 50 pin header
A24A24 channel mounting card for solid state I/O modules, 50 pin edge connector $149
CAB50-6Ribbon cable with 50-pin female edge connector on one end and 50-pin female connector on the other end $30
Model Options:
-LV Factory option for 3.3V LVTTL signaling on digital connectors
-M Molex PC-style connector for maximum 5V VCCIO current sourcing capability
-RoHSRoHS compliant version
-T Extended temperature (-40°C to +85°C)

Acquisition, Control, Communication: Engineering and Systems