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5.3 The System Switching Function
5.3.3 System Switching Execution Possibility
5
POINT
1. Make sure to set "CPU Operation Mode" to "STOP (default)" on the details
settings of the PLC parameters I/O Assignment settings.
If set to "Continue", system switching cannot be executed when the
"SP. UNIT DOWN" error occurs due to a network module hardware failure.
Table5.27 Operating Status and Details
Operating Status
Description
Normal
The CPU module is in the RUN, STOP or PAUSE status, where no error such as a continuation error or stop
error has occurred.
Continuation Error
The CPU module is in the RUN, STOP and PAUSE status, where a continuation error has occurred.
Stop Error
The CPU module has stopped, as a stop error has occurred.
Power Off
The system power is OFF.
Resetting
The CPU module is being reset.
At network fault detection
A fault has been detected by at least one module of standby system network modules
(CC-Link IE Controller Network module, MELSECNET/H module, Ethernet module, PROFIBUS-DP master
module).
Preparing for Tracking
The communication is not made between the control system and standby system via tracking cable.
System Switching Request
Timeout
The system switching has not been completed, as a data error occurred due to noise, etc., in the
communication between the control system and standby system during system switching processing.
Executing System Switching
System switching cannot be executed since the control system or standby system is executing system
switching due to the previous system switching condition.