At a Glance

  • Detect Loss of Control in Machine Automation
  • Optimized for PLCs, Single Board Computers and Distributed Control Systems
  • Edge-triggering
  • Timeouts from 50 ms to 24 hours
  • "Double Redundant" Design
  • Industrial Rugged: -40 to +85 deg. C.
  • 3 Year Limited Factory Warranty
  • 8 Amp SPDT Dry Contact Output
  • 3-30 VDC Opto-Isolated Input
  • PLC Sinking or Sourcing Logic
  • 5-28 VDC Supply Voltage Range
  • Fast/Slow Input LED
  • “First-Fault” lock-out
  • 90-132VAC/60Hz  Power Line Monitoring
  • Power-up Trigger
  • Dual-Edge Triggering
  • Factory-calibrated +/-1% Timer Tolerance
  • Customize It! IPD is glad to quote your specific custom module


The P8D-WDT24/PLC Watchdog Timer Module is a fully-digital implementation of the field-proven P8-WDT24/PLC Watchdog Timer, setting new standards for control system monitoring. 

The goal of a watchdog timer is to monitor important controller-health conditions and make sure that its output is energized only when all supervised timing conditions are satisfied.  The P8D-WDT Watchdog Timer provides the features and capabilities that are needed to provide fault detection and protection for the most sophisticated industrial control systems, especially Machine Controls and Robot Controls.  It is optimized to work with Programmable Logic Controllers (PLCs), One-board Controllers, and Distributed Control Systems by providing high-reliability, ease of integration, and a deep range of capabilities. 

High Reliability  The P8D Watchdog timer has a “double-redundant” design that uses a combination of proven technologies to supervise its own integrity as well as the monitored system, providing the highest level of control system integrity. Encapsulated circuitry and industrial operating temperature make the P8D-Series well suited to robust industrial applications.

Ease-of-Integration  Its compact low-profile package makes it easy to integrate onto panels or DIN rails using industry-standard Octal Relay Sockets such as the Brentek DIN8.  The wide 5-28 VDC supply voltage covers all standard industrial controls voltages.  The input is optically-isolated and can accept 3- 30 VDC trigger pulses from either Sourcing Logic or Sinking Logic.  Its SPDT FORM C dry contact output is rated for 8 Amps@ 30VDC/250VAC allowing it to directly control most loads –even contactors!  

Deep Range of Capabilities  A host of sophisticated new configuration features include fixed time-outs from 50 milliseconds to 24 hours, user-specified adjustable timing ranges , a “first-fault” lock-out function requiring a user reset after a system fault occurs, quantitative LED indication of input pulses, enhanced trigger tolerance for inductive load “spikes”,  90-132VAC/60Hz line monitoring, plus others.

The P8D-WDT Watchdog Timer from Brentek is the solution to monitoring the “heartbeat” of today’s ultra-sophisticated mission-critical control systems.  For further information, see the P8D Datasheet.  If you would like to discuss your application with an engineer, please contact us and we will be happy to help. 


How to Purchase Customize It!