Rockwell Automation 999 IMC S Class Compact Motion Controller (Cat. No. 4100-999-122) - Manual (Page 71)

Installation and Hookup 4-29
Publication 999-122 - January 1997
Connecting the CPU
Watchdog
The IMC-S/23x provides a fail-safe CPU watchdog with relay-contact
outputs for connecting into your machine’s start/stop string or other
protective circuit. Form-C (NO and NC) contacts are provided to allow
external equipment to be disabled in the event of a control malfunction.
The CPU watchdog relay is activated during normal operation and
deactivates when there is a malfunction. A front-panel indicator
(System OK) is illuminated whenever the CPU watchdog is activated.
The CPU watchdog relay contacts are UL/CSA rated for 1 Ampere at
30V DC.
Connect the CPU watchdog contacts into the start/stop string of your
machine using the 4100-CCWxxF pre-engineered cable assembly. The
CPU watchdog contacts may be used directly in 24V DC start/stop
strings; a typical connection is shown below.
An external relay driven from the CPU watchdog contacts must be used
when switching AC. A typical connection for an AC start/stop string is
shown below.
The connections shown in the figures above are typical only. They may
be modified as required for your application if they cannot be used
exactly as shown.