Mitsubishi Electric MELSEC iQ-R Series User Manual page 173

When network modules are mounted on the main base units
Wait until the network module of the system B starts up. Then, execute the system switching instruction.
When CC-Link modules are mounted on the main base units, the system B cannot be started up as the control
system. (The system A with the CC-Link module always starts up as the control system.)
■In a redundant master station configuration or a redundant device station configuration
• System configuration
(Redundant master station)
System A
(master station) Tracking cable
(Redundant device station)
Master station
To start up the system B as the control system, connect network modules in a loop. (In a redundant master
station configuration or a redundant device station configuration, if the network is configured in the line
topology and link-down occurs in the network modules of the system A, link-up between the network modules
of the system B cannot be detected. Therefore, the system switching instruction is not executed and the
system A starts up as the control system.)
Local station
System A
(local station) Tracking cable System B (local station)
11 BASIC CONCEPT OF REDUNDANT SYSTEM
11.6 System Determination
11
System B
(submaster station)
171