Log In

Credit Cards Accepted
Thomas Supplier



acces logo

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


pcie digital i/o
  • 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


  • 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)

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.


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 2000/XP/2003/Vista/7 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.

pcie digital i/o block diagram

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 2.20" (55.8mm) high


  • Call

OEM and volume pricing available, please call us 1-877-902-2979  

Ordering Guide
PCIe-DIO-48S PCI Express 48 channel digital I/O card with change of state detection  
PCIe-DIO-48 PCI Express 48 channel digital I/O card without change of state detection  
PCIe-DIO-24S PCI Express 24 channel digital I/O card with change of state detection  
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  
-RoHS RoHS compliant version  
-T Extended temperature (-40°C to 85°C)  
STB-50 DIN-rail mountable screw terminal board for 50 pin header type connector $44  
CAB50F-6 50 pin ribbon cable with female header connectors, 6 feet long $30  
STB-48CH 48 digital I/O single screw terminal board $149  
IIB-24 24 channel optical isolater board for each 50 pin header $149  
ROB-24 24 channel electromechanical relay card for each 50 pin header  
A24A 24 channel mounting card for solid state I/O modules, 50 pin edge connector $149  
CAB50-6 Ribbon cable with 50-pin female edge connector on one end and 50-pin female connector on the other end $30  



Available Reference Manuals

Available Datasheets

Further information about available ACCES Software:

Drivers And Operating Systems
What drivers and other support we provide for various operating systems.

Setup Programs, Samples, And Utility Software
A description of the software package that comes with each ACCES card.

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.

Custom Software Services
A description of some of our custom software offerings. Did you know we offer free programming services to qualifying customers?
Acquisition Control Communication Engineering and Systems
USA Office

Address: 1480 Gulf Road, Suite 837,
PO Box 1364
Point Roberts, WA 98281

Western Canada - Vancouver BC

Tel:1.800.663.6001 or 1.604.925.6150
Address: 2454 Haywood Ave
West Vancouver, BC V7V 1Y1

Eastern Canada - Markham, Ontario

Tel:1.800.465.0164 or 1.905.513.7027