The watchdog module has two fundamental functions:

• Monitoring of the ET 200iSP remote I/O station for hardware failures (hardware lifebeat); external, applicative failure monitoring is also possible via an I/O address area of the module
• Intrinsically-safe power supply for external actuator switch-off

The watchdog module must be plugged onto a terminal module (order separately). The following terminal modules are suitable for this:

• TM-IM/EM60 terminal modules for one interface module and one watchdog, reserve or electronics module (for versions, see Interface module section)
• TM‑EM/EM60 terminal modules with two slots for watchdog module, reserve module or electronics modules (except 2 DO relay):
  • with blue screw-type or spring-loaded terminals for hazardous environments
  • with black screw-type terminals for non-hazardous environments

The first slot directly next to the interface module is provided for the watchdog module.