Wiring An External Alarm Or Annunciator To The Watchdog Connector And Wiring The Redundancy Control Input (Optional) - Emerson ControlWave Instruction Manual

2.3.7 Wiring an External Alarm or Annunciator to the Watchdog
Connector and Wiring the Redundancy Control Input
(OPTIONAL)
Caution
Connections TB3-5 = VO - Watchdog switch output
Revised Aug-2015
ControlWave I/O Expansion Rack Instruction Manual
At this time you can also connect power and watchdog wiring.
However; for safety reasons and to prevent accidental damage to the
your bulk DC power supply, do not connect the pluggable terminal
block connectors TB1, TB2, or TB3 to the PSSM until after you install,
wire, and configure the CPU module.
Follow the instructions in Section 2.3.4
when wiring connections.
When the CPU's hardware detects improper software operation, it
triggers a watchdog condition and resets the CPU. If you have enabled
the watchdog output using jumper JP1, the watchdog condition triggers
a failure to the redundant unit.
The circuit that drives the watchdog switch is on the secondary side of
the power supply. A solid state relay actuates the watchdog hardware
and is factory enabled or disabled via jumper JP1 (see Setting Jumpers).
Figure 2-14. Watchdog Switch Field Wiring
The VI input of the terminal block (TB3-6) powers the watchdog
switch. Its switched output connects to the VO output of the terminal
block (TB3-5). Reference the external power source connected to the VI
terminal to the return point of the input source that powers the PSSM [-
VIN (TB1-2)].
PSSM connector TB3 provides watchdog switch and redundancy
control connections as follows:
TB3-6 = VI - Watchdog switch input
TB3-7 = VR - Redundant unit control input (Used with CW RED I/O)
Installation
General Wiring Guidelines
2-21