OSx Station Control 2-19SIMATIC PCS 7 OSx 4.1.2 Operator
Outstanding alarms — Operators need to check the alarm summary for
all alarm groups to see if any alarms occurred during failover. If an
alarm occurs in the controller during the failover period, the alarm icon
and the alarm summary line do not flash. However, the system writes
the alarm to the alarm summary.
Backup designation — When a backup becomes primary after a
failover, no backup exists for the system. Designate a new backup, in
case another failover o ccurs.
OSx Station
(Supervisory)
Programmable Controllers
Industrial Ethernet
OSx Station
(Operator)
OSx Station
(Operator)
OSx Station
(Supervisory)
OSx Station
(Supervisory)
24 VAC or
VDC Power Supply
(User-Supplied)
Failover circuit is connected to station
alarm card. (Cable is user supplied)
¯
BackupPrimary
If primary
① fails, the backup ② automatically assumes role of primary.
After station
② becomes primary, station ③ becomes available for designation as next
backup. Neither station
④ nor ⑤ can be the backup because they are operator stations.
Figure 2-4 Failover Configuration for a Multiple-Station System