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PCI Express Watchdog Timer Status Monitor


  • 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


  • Industrial operating temperature (-40°C to +85°C)
  • RoHS Available. Please contact us for ordering information
  • Low Profile mounting bracket


This multifunction Low Profile x1 PCI Express card contains a watchdog timer used to monitor the operation of your application program and operating system to initiate a system reset in case of a lockup. It can also monitor and control a variety of system hardware parameters. The card is 6.6 inches long and 2.535 inches seated height. I/O wiring connections are via a female DB25 connector on the card mounting bracket. Two models with increasing features are available.

The PCIe-WDG-CSM card contains a watchdog timer and on-card RGB LED and speaker alarm to signal watchdog timeout. A DPDT relay, two LVTTL inputs and two outputs, and fused 3.3V general purpose outputs are accessed via the DB25 female I/O connector on the card mounting bracket.

An advanced model, the PCIe-WDG-CSMA, is also available which includes an A/D converter to monitor the computer power supply, and sensors to monitor the internal temperature and humidity, ambient light, and comes with a remote temperature sensor on a 19 cable. A pair of opto-isolated outputs and four opto-isolated inputs are available for general purpose use.

PCIe-WDG-CSMA: Advanced Feature Pack* Advanced software package multiplies the power of your Watchdog.

Create a customized configuration package and upgrade your PCIe-WDG-CSMA device to:

  • Protect your computer from common problems that can occur during power-on self test (POST)
  • Control one or more outputs when input(s) toggle or other Events occur
  • Schedule output changes to occur periodically or at a specific time
  • Play WAV files when Events happen, including Growl, Bark, "LVTTL0 falling edge detected", etc.

All features can be configured through either a Windows GUI-based settings program or our flexible AIOWDG.dll API, with settings stored in onboard non-volatile memory.


The PCIe-WDG-CSMA is designed for use in both industrial/commercial and optionally military environments of 0 to +70°C and -40 to +85°C, respectively. Programmable array logic is available on this card and many possibilities exist for special modifications to suit unique requirements.


The PCIe-WDG-CSMA is supported for use in most operating systems and includes a free Windows and Linux (including macOS) compatible software package. This package contains sample programs and source code in C#, Delphi, and Visual C++ for 32-bit and 64-bit Windows. Also provided is a graphical setup program in Windows. Linux support includes installation files and 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 VIs. Embedded OS support includes the family of Windows Operating Systems including IoT, please contact ACCES for compatibility with your specific OS.

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.

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
  • Environmental

  • Operating Temp: 0°C to +70°C (optional -40°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.

    ModelPrice (USD)

    Ordering Guide
    PCIe-WDG-CSMAAdvanced PCI Express watchdog timer card, all options, monitor voltage, humidity, temperature, light, and more
    PCIe-WDG-CSMStandard PCI Express watchdog timer card
    ADAP25MDirect connect screw terminal adaptor for use with 25-pin female connector $50
    STB-25DIN-rail mountable screw terminal board for use with any ACCES card that has a 25-pin mating connector $44
    CAB25MF-18Ribbon cable, male to female 25-pin connectors, 18" $29
    CAB25MF-XXAs above except "xx" equals length in inches (add $2 per Ft over 18")
    DIN-SNAP(-6)One foot length SNAP-TRACK with four clips for mounting up to two STB-xx screw terminal boards $20 (6" version also available for $15.00)
    Model Options (call for pricing)
    -TIndustrial Operating Temperature (-40°C to +70°C)
    -LLow profile bracket installed
    -RoHSRoHS compliant version
    -CCConformal coating for use in high humidity and dusty environments

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

    Acquisition, Control, Communication: Engineering and Systems