Mitsubishi Electric MELSEC iQ-R Series User Manual page 68

Checking method
Check the LEDs of each redundant function module to check the system status.
Setting of the engineering tool
System A
System B
When the setting is switched from "System A" to
"System B"
Users can also check the system status on the engineering tool. ( GX Works3 Operating Manual)
• System monitor
• "System A/B Setting" window
• Monitor status bar
Precautions
• Do not power off the system or reset the CPU module during the system A/B setting. The system A/B setting may not be
reflected properly. If not reflected properly, set the system again.
• For the system A/B setting, use the CPU module that is connected with a USB cable or an Ethernet cable. If the connection
destination has been changed on the engineering tool, the system A/B setting cannot be set.
• The system A/B information cannot be deleted once it is set. The information can only be changed.
• If the system A/B setting has not been set or the same system A/B setting has been set when both systems are started up
simultaneously, a stop error occurs at the point when tracking communications are established. Set the system A/B setting
correctly in both systems.
• If a system with no system A/B setting is started up first, a stop error occurs at the point when tracking communications are
established. Set the system A/B setting correctly in both systems. In a redundant system with redundant extension base
unit, if the system A/B setting has not been set in both systems, the modules on the extension base units does not start.
• Do not connect system A and system A or system B and system B with tracking cables while running. If connected, a
continuation error will occur.
5 PROCEDURE FOR STARTING UP A REDUNDANT SYSTEM
66
5.5 Setting the System (System A or System B)
LED of the redundant function module
When the setting is switched to "System B", the SYS B LED flashes.
Powering off and on the system or resetting the CPU module turns off the SYS A LED and turns on
the SYS B LED.