Precautions - Mitsubishi Electric MELSEC iQ-R Series User Manual

Precautions

Operation at power-on
In a redundant system without extension base units, when the RUN/STOP/RESET switch of the CPU module of each system
is set to the RUN position and both systems are powered on, the CPU module of the control system starts in the STOP state
and is switched to the RUN state after reflecting the tracking data is completed in the CPU module of the standby system.
(The same operation is performed when one system is powered on while the other system is waiting for the start-up of the
other system.)
Since the operating status of the CPU module in the control system and that of the CPU module in the standby system do not
march until the operating status of the CPU module in the control system is switched from the STOP state to RUN state, the
BACKUP LED of the redundant function module flashes.
When the time of the initial processing and that of the initial processing (when switched to RUN) of the CPU module in the
standby system are longer than those of the CPU module in the control system, the operating status of the CPU module in the
control system may not be immediately switched to the RUN state after power-on.
In a redundant system with redundant extension base unit, the CPU module is switched to RUN after about three seconds
from when one system is powered on, without waiting for the standby system tracking data to be reflected.
Device data used by the CPU module of the new control system
After system switching, the CPU module of the new control system starts operations by using the device/label data received in
tracking transfer. The following table shows device/label data used by the CPU module of the new control system by tracking
data receive status at system switching.
Device/label initial value
Not set
Set
No tracking data received
Operation starts based on the latched device/
label data.
Operation starts based on the device/label data
that is set with device/label initial values.
Tracking data received once at least
Operation starts based on the device/label data that is transferred
from the old control system.
When the synchronous tracking mode is used as a tracking mode,
the data in the old control system at the final scan start is used by
the new control system.
26 REDUNDANT FUNCTION
26.3 Tracking Transfer
26
403