Precautions - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

Precautions

The following describes the precautions for switching the operation mode.
Switching of the operation mode in the RUN-transition instruction waiting state
When the operation mode is switched to the separate mode, the standby system CPU module is set to the RUN-transition
instruction waiting state (same as the STOP state). If the operation mode is switched to the backup mode in this state, the
standby system CPU module goes to the RUN state.
The following describes the precautions for this state.
• If the SP.CONTSW instruction is executed before the standby system CPU module goes to the RUN state (during initial
processing (when switched to RUN)), the operating status of each of both systems becomes different and a continuation
error will occur. ( Page 453 System switching during initial processing/initial processing (when switched to RUN))
• If the standby system CPU module takes time to switch to the RUN state due to causes such as access to a file in the
standby system CPU module, the operating status of each of both systems becomes different and a continuation error
occurs.
Switching the mode during initial/initial processing (when switched to RUN)
When the operation mode is switched during initial processing or initial processing (when switched to RUN), the operation
mode is switched after the initial processing or initial processing (when switched to RUN) is finished. Even if the initial
processing or initial processing (when switched to RUN) takes time and a communication error occurs, the operation mode is
switched after the initial processing or initial processing (when switched to RUN) is finished.
Consecutive operation mode switching
To consecutively switch the operation mode, switch the operation mode in certain intervals. If the operation mode is changed
again before the operating status is switched by the previous operation mode switching, the operating status of each of both
systems becomes different and a continuation error will occur.
28 FUNCTIONS
440
28.1 Operation Mode Change