Rockwell Automation 1785-CHBM ControlNet PLC-5 Hot Backup System User Manual - Manual (Page 81)

1 Publication 1785-UM024B-EN-P - January 2003
Appendix
B
Backup States
Chapter Objectives This Appendix describes the possible backup states and backup state
transitions of the PLC-5 ControlNet backup system. There are four
main backup states:
• Invalid
• No Control
• Primary (and Lonely Primary)
• Secondary
POWERUP
NON_BACKUP
NO
CONTROL
STATE
PRIMARY
STATE
SECONDARY
STATE
NO BACKUP
CARD
STANDALONE
IN RUN MODE
PRIMARY FOUND,
QUALIFICATION PASSED,
IN RUN MODE
NOT IN
RUN MODE
NOT IN
RUN MODE
SWITCHOVER
BACKUP STATE DIAGRAM
INVALID
STATE
INVALID
BACKUP
CONFIGURATION
VALID
BACKUP
CONFIGURATION