Executing Method; Precautions For Redundant System - Mitsubishi Electric MELSEC iQ-R Series User Manual

Executing method

Using an engineering tool
Perform remote RESET with the remote operation of the engineering tool. ( GX Works3 Operating Manual)
In a redundant system, the operation is as follows.
■Backup mode
The CPU modules of both systems can be reset by performing remote RESET operation on the CPU module of the control
system. Only the CPU module of the standby system can be reset by performing remote RESET operation on the CPU
module of the standby system.
Select "Control System" or "Standby System" in the transfer setup, and select "Currently Specified Station/Specify Both
Systems" in "Specify Execution Target" of "Remote Operation".
However, if remote RESET operation is performed on both systems in backup mode, note the following.
• When the CPU module of the control system is in the STOP state and the CPU module of the standby system is in the RUN
state, performing remote RESET operation on the CPU module of the control system causes system switching. To prevent
system switching in remote RESET operation, perform remote RESET operation after setting both of the CPU modules to
the STOP state.
• When remote operation is performed on the CPU module of the control system or standby system through another path,
the CPU module of the standby system cannot be reset by performing remote RESET operation on the CPU module of the
control system. To perform remote RESET operation on the CPU module of the control system or standby system, use the
path that was used to perform the remote operation on the CPU module of the standby system. Cancel the remote
operation first and perform remote RESET operation.
• When performing remote RESET operation on both systems, select "Control System" in "Specify Redundant CPU". When
"Not Specified" is selected, an error may occur depending on the timing of the operating status change of each CPU
module.
[Online]  [Current Connection Destination]  [Specify Redundant CPU]
• When the control system or standby system is in the initial processing (the READY LED is flashing), do not perform the
remote operation of "Specify Both Systems". If such an operation is performed, both systems may be recognized as being
mismatched in the system consistency check because the operating statuses may be mismatched.
■Separate mode
Only the CPU module of a system specified in the transfer setup of the engineering tool can be reset. The operating status of
the CPU module in a system not specified is not changed.
By an external device using SLMP
Perform remote RESET with the SLMP command. ( SLMP Reference Manual)
16.5

Precautions for Redundant System

The following describes the precautions on the remote operation in the redundant system.
• When the control system or standby system is in the initial processing (the READY LED is flashing), do not perform the
remote operation of "Specify Both Systems". If such an operation is performed, both systems may be recognized as being
mismatched in the system consistency check because the operating statuses may be mismatched.
• If remote RESET is performed for both systems when the load of each CPU module is high in a redundant system with
redundant extension base unit, the module on the extension base unit may not be reset and each CPU module may not
start up successfully. If each CPU module does not start up successfully, execute remote RESET for both systems again.
16 REMOTE OPERATION
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16.5 Precautions for Redundant System