Switchover Conditions

The 1747-BSN module transfers control from the primary to the secondary

processor (switchover) if one of the following fault conditions occurs in the

primary system:

• power failure

• major fault in the processor

• 1747-BSN module fault

• primary processor mode change from Run to Program

Note: In order for switchover to occur, both primary and

secondary modules must be working without faults prior

to the event that triggers the switchover.