Mitsubishi Electric MELSEC Q Series Reference Manual page 146

(c) When station No.1 is reconnected to the network
Station No.1 that was disconnected due to a communication error is reconnected to the network as a normal
station when it recovers from the error. At this time, system switching does not occur.
Cyclic transmission after reconnection of station No.1 is illustrated below.
LB0 to LBFF
LB100 to LB1FF
LB200 to LB2FF
144
Redundant system
System A System B
(standby system) (control station)
Normal station Sub-control station
No.1 No.2
Tracking cable
Link relay (LB)
No.1, 2 send range
No.3
No.4
LB7FFF
The same send range is used for station
No.1 and 2 by tracking transfer.
Normal station
No.3
No.1, 2 send range No.1, 2
No.3 No.3 send range
No.4 No.4
Normal station
No.4
No.1, 2
No.3
No.4 send range