PCIe-WDG-CSMA Watchdog Timer and System Monitor Card

ACCES: Committed to Service

We're here to help!

Let our amazing support staff help you with questions: whether finding the right model for you, or technical support on using the product - or figuring out what's wrong - we have the expertise to help you. Use it!

Call, E-Mail, or Chat, Today!


  • Low Profile PCI Express watchdog timer and computer status monitor card
  • Open collector transistor output to ground power good line or reset switch via pass through upon timeout
  • DPDT relay contacts notify external devices when reset signal occurs
  • 2 LVTTL outs & 2 LVTTL inputs (5V tolerant)
  • DB25 female connector on mounting bracket
  • RGB LED at mounting bracket provides at-a-glance status information
  • Onboard speaker
  • EEPROM for configuration and firmware
  • Designed, made, supported, and manufactured in the USA

Advanced Model Features

  • Analog to Digital Converter with integrated temperature and humidity sensors and multiplexed inputs
  • +12V and +3.3V PCIe Power Monitor
  • Ambient light sensor
  • External LM335 temperature sensor
  • 4 Isolated digital inputs accept up to 31VDC
  • 2 Isolated FETs switch from 5 to 34VDC

Factory Options

  • Industrial operating temperature (-35°C to +70°C)
  • RoHS Available
  • Low Profile mounting bracket
Last updated on November 2, 2023, 6:30 pm


In Stock
SKU: N/A Categories: , Tags: ,


Data Sheets



Drivers and Downloads

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

Information about our Free Software packages:

ACCES is proud to provide a full suite of software support with every Data Acquisition product. We are committed to supporting the most popular operating systems and platforms for our customers. Currently we are actively supporting XP -> 10, both 32 & 64 bit, including “Server 2008,” “Embedded,” and “Compact” flavors for all plug-and-play products including PCI, PCI Express, USB, and more. Many products continue to ship with support for additional operating systems such as DOS, Windows 95, 98, Me, NT4, and 2000.


Among the software we deliver with our products are sample programs in a wide variety of programming languages. These samples are used to demonstrate the software interfaces to our products — and many can be used as-is in your production environments, or to test functionality of the devices out-of-the-box. We’re currently actively supporting sample programs in Microsoft Visual C#, Visual Basic, Delphi, and Visual C/C++, with many devices including samples in Borland C/C++ 3.1 for DOS. Additionally we provide National Instruments LabVIEW compatible DLLs and many demonstration VIs for our devices.


Drivers for various operating systems are also provided, including active support for Windows XP -> 10 — all in both 32-bit and 64-bit flavors, and including consumer, server, and embedded varieties — as well as the 2.6 and newer Linux kernels and recent OSX / macOS versions. Many products continue to ship with driver support for Windows 95, 98, Me, NT4, and Windows 2000, but support for these operating systems is considered deprecated.

Setup Programs and Utilites

Our Data Acquisition devices also include a graphical setup utility that walks you through the process of configuring any option jumpers or switches on the device, as well as explaining a little about the various connectors present.

Many devices also include utility programs – little tools to make your use of the device easier, such as EWriter, a program that allows you to read and write data in the user-accessible EEPROM locations on all our USB data acquisitition products; or WinRISC, a “Really Incredibly Simple Communications” terminal program that lets you get started instantly with serial devices.

“Register Level” Documentation

Besides all this software in all these languages and operating systems ACCES has a policy of open and transparent development: none of our lowest-level “register” interfaces are hidden from you — we document every register in every bus card, every command in every serial board, and every usb control transfer in every USB Data Acquisition board. These lowest-level interfaces allow you to develop for our products in ANY operating system or language, regardless of our actively supporting it or having a driver for it. We have customers actively developing in ADA, Android, Python, Java, MATLAB, Solaris, and more, just by referring to our complete low-level interface documentation! And we provide the full source code to all of our drivers, regardless of operating system, to give you an even bigger head start in your own development tasks.

No Fees or Royalties

All of this software is provided at no additional charge, and is licensed under any of a variety of flexible — and royalty free — options. Check out our software license explanation if you’d like more information.

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.

Block Diagram

Two Digital Inputs

  • Pull-up resistors: 10k ohm

Two Digital Outputs

Logic Levels

  • 3.3V
  • Input Low ≤ 0.8V, ≤1µA
  • Input High ≥2.0V, ≤1µA
  • Output Low ≤0.4v, ≤8mA
  • Output High ≥2.4V, ≤8mA


  • Contacts: Dual Form C (DPDT)
  • Nominal Ratings: 1A, 30VDC, 0.5A 125VAC (resistive)

Reset Output

  • Open Collector Transistor to ground

Isolated Digital Inputs

  • Quantity: 4, PC isolated, sharing a common return
  • Type: Opto-couplers
  • Voltage Range: 3 to 31 VDC
  • Isolation: 500V channel-to-ground
  • Input Resistance: 1.8K ohms in series with opto coupler

Isolated FET Outputs

  • Quantity: 2, PC isolated, sharing a common return
  • Output Type: High Side Power MOSFET Switch Protected against short circuit, over-temp., ESD, can drive inductive loads
  • Voltage Range: 5-34VDC (customer supplied)
  • Current Rating: 2A maximum
  • Minimum load: Required

Computer Status Monitor (I²C Interface)

Sensors (2)

  • Ambient Temperature: -40°C to +125°C ±0.3 – 0.7% typical
  • Relative Humidity: 0-100% RH, ±3% typical

Analog Inputs (4)

  • 3.3V from PC Supply
  • 12V from PC Supply
  • Ambient Light Sensor
  • LM335 Temp Sensor


  • Operating Temp: 0°C to +70°C (optional -35°C to +70°C)
  • Storage Temp: -55°C to +150°C
  • Humidity: 5% to 95% RH, non-condensing
  • Card Dimensions: 6.6 inches length; height 2.535 inches seated

Regulatory Compliance

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

OEM and volume pricing available, please contact us.

ModelDescriptionPrice (USD)

PCI Express watchdog timer card, with Temperature/Humidity sensor


Standard PCI Express watchdog timer card


Advanced PCI Express watchdog timer card, all options, monitor voltage, humidity, temperature, light, and more

Direct Connect Terminal Board
ADAP25M Direct connect screw terminal adaptor for use with 25-pin female connector $50
Cable Connectivity
CAB25MF-18 Ribbon cable, male to female 25-pin connectors, 18″ $29
CAB25MF-XX As above except “xx” equals length in inches (add $2 per foot over 18″)
STB-25 DIN-rail mountable screw terminal board for use with any ACCES card that has a 25-pin mating connector $44
DIN Rail Mounting
DIN-SNAP One foot length SNAP-TRACK with four clips for mounting up to two STB-xx screw terminal boards $20
DIN-SNAP-6 6 inch length SNAP-TRACK with two clips for mounting up to one STB-xx screw terminal board $15
Model Options (call for pricing)
-T Industrial Operating Temperature (-40°C to +70°C)
-L Low profile bracket installed
-RoHS RoHS compliant version
-CC Conformal coating for use in high humidity and dusty environments
-TH Temperature and Humidity Monitor for the PCIe-WDG-CSM

If you don’t see what you need, ask us and we will make it for you.