Mitsubishi Electric MELSEC iQ-R Series User Manual page 384

In separate mode
: Switching possible, : Switching not possible
Redundant system status
Normal operation or continuation error in the
standby system
Tracking communications disabled (cable
disconnection)
Power-off, reset, hardware failure of the CPU
module of the standby system
Stop error in the standby system
Network error detected in the standby system
During memory copy from control system to
standby system
During online program change
Operating status mismatch of the CPU modules
in both systems
During system switching
During online Redundant function module
module change
Module on the main base unit
in a redundant system with
redundant extension base
unit
Other modules
System switching disabled by the DCONTSW
instruction
*1 When the group specification has been set in the standby system, a network error is not detected if communication is available with the
line of an Ethernet-equipped module after a communication error has occurred on the other Ethernet-equipped module. ( MELSEC
iQ-R Ethernet User's Manual (Application))
*2 If system switching is disabled when a system switching request is sent, a continuation error occurs and a cause of a system switching
failure is stored in SD1644 (Cause of system switching failure).
*3 If system switching is disabled when a system switching request is sent, the error code corresponding to a cause of the system
switching failure is returned.
*4 In a redundant system with redundant extension base unit, If the system switching timing and the interrupt timing of the internal timer
overlap, the interrupt interval for the internal timer may be extended in the CPU module of the control system after system switching.
Occurrence of a cause of the system switching failure
When a cause of the system switching failure occurs, the BACKUP LED flashes in backup mode and the SEPARATE LED
flashes in separate mode.
The cause to flash the BACKUP LED or SEPARATE LED can be checked in SD1642 (BACKUP/SEPARATE
LED flashing cause). Check SD1642 and eliminate the cause to flash the LED.
26 REDUNDANT FUNCTION
382
26.2 System Switching
Execution availability of system switching
Automatic system switching
Power-off, reset, Stop error
hardware failure of the CPU
of the CPU module
module
 
 
 
 
*1
 
 
 
 
 
 
 
 
 
Manual system switching
System System
switching switching
request from a request by the
network module SP.CONTSW
instruction
 
 
 
 
 
 
 
 
 
 
 
 
 
*4
System
switching
request from the
engineering
*2 *3
tool












