Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 62)

Publication 1747-UM010B-EN-P - September 2003
4-10 Operating Your SLC 500 Backup System
Power Down Sequencing No special considerations (beyond the standard precautions for a
programmable controller) are required when powering down the
system. Power down should begin with the secondary system and
proceed to the primary. If the primary system is powered down first, a
switchover occurs.
Restarting a Failed System A failed system that has been repaired can be restarted as described in
the following sequence. It is not necessary to power-down or change
the mode of primary SLC 5/0x.
1. Set the secondary SLC 5/0x (processor of the repaired system) to
program mode.
2. Apply power to the secondary system.
3. Download the applications program to the secondary SLC 5/0x.
4. Change the backup processor mode of operation from Program
mode to Run mode.