Mitsubishi Electric MELSEC iQ-R Series User Manual page 162

Item
Link refresh
Writing data to the
programmable
controller
Remote operation
function
Time synchronization
11 BASIC CONCEPT OF REDUNDANT SYSTEM
160
11.5 Operation Modes of a Redundant System
Backup mode
In the standby system, data is not refreshed from devices of the
CPU module to link devices.
Data can be simultaneously written to both systems. Or, data can
be written to only a system specified in the connection
destination setting.
Remote operations can be performed on both systems.
Time of the standby system is synchronized with that of the
control system.
Separate mode
In the standby system, data is refreshed from devices of the CPU
module to link devices (only the link special relay (SB) and link
special register (SW)). (CC-Link is excluded.)
Data can be written to only a system specified in the connection
destination setting.
Remote operations by the engineering tool can be performed
only on a system specified in the connection destination setting.
Time is not synchronized.