At a Glance

  • 24V PLC Sourcing Logic Compatible
  • Positive-edge Triggering
  • System Fail-safe FORM C Output
  • Compact Encapsulated Design
  • -40 to +85 deg. C Operation
  • 3 Year Limited Factory Warranty
  • 2 Second Fixed Timeout
  • Power and Output LEDs
  • 8-pin Octal Socket Compatibiilty
  • 5 Adjustable Timeout Ranges
  • Opto-isolated Input
  • Input State Indicator LED
  • Customize It! IPD is glad to quote your specific custom module


Brentek P8-WDT24/PLC Watchdog Timers monitor controller integrity as a “System Watchdog” in industrial controls, including PLC (Programmable Logic Controller), SBC (Single-board Controller) applications. Watchdog Timer Modules monitor the control system’s activity by detecting on/off transitions of a control line. During normal operation, the watchdog’s internal timer is continually reset by control line activity and its FORM C DRY Contact output remains energized. When control is lost (control line stops toggling), the timer times-out and de-energizes the output contact, indicating “Loss of Control”.  If power is lost, the output also de-energizes.  (See P8D-ISM for a Watchdog Timer with Power Supply Voltage Monitoring)  

Loss of Control is caused by problems such as CPU latch-up, control system faults, wiring/cabling failure, unauthorized tampering, unanticipated software conditions, communications problems, or power failures. The system designer can use the watchdog timer's output contact to address Loss-of-Control by energizing an alarm, shutting down the system, or providing a reset signal to the CPU/controller.

The standard P8-WDT24/PLC has 24VDC operation, a 2 second fixed timeout, a FORM C (8 Amp / 2000 VA) SPDT Dry Contact output relay, and an internal input pull-down for direct connection of the watchdog's input to PLC 24V sourcing logic. Optional timing configurations of the P8-WDT24/PLC are available with 5 different adjustable timeout ranges or fixed timeouts ranging from 0.075 Seconds (75 milliseconds) to 60 seconds. Input options include optical-isolation and an input state indicator LED.

The P8-WDT24/PLC Watchdog Timer's Low Profile packaging is a direct plug-in to industry standard 8-pin octal sockets, such as Brentek's DIN8 which can be either DIN rail or panel mounted.

The Brentek P8-WDT24/PLC Watchdog Timer Is available from IPD, Inc. on Amzaon.   The 2-second fixed timeout P8-WDT24/PLC and two adjustable timeout configurations of the P8-WDT24/PLC are available on Amazon.   Also, the P8-WDT24/PLC-ISO watchdog timer with opto-isolated input is available on Amazon.  

How to Purchase Customize It!