Mitsubishi Electric MELSEC iQ-R Series User Manual page 386

■Special register
The following table shows the special register numbers for system switching and the storage status of the CPU modules in the
control system and standby system.
: Stored, : Not stored
SD No. Name
SD1642 BACKUP/SEPARATE LED flashing cause
SD1643 System switching cause
SD1644 Cause of system switching failure
SD1645 System switching request status from a network module of own system
SD1646 System switching request status from a network module of the other system
SD1648 Cause of the other system monitoring error
SD1649 System switching cause (when the systems are successfully switched)
SD1650 System switching instruction ID number
*1 When the system switching has not been normally completed, a value is stored in this special register area of the control system.
CTRL LED and SBY LED of the redundant function module
System switching results can be checked with the CTRL LED and SBY LED on the front of the redundant function module.
Control system  Standby system
26 REDUNDANT FUNCTION
384
26.2 System Switching
*1
Standby system  Control system
Storage status at system switching
CPU module of the new CPU module of the new
control system standby system
 
 
 
 
 
 
 
 