Precautions For Writing Device Data From Other Station - Mitsubishi Q12PRHCPU User Manual

6
REDUNDANT SYSTEM NETWORKS

6.5 Precautions for Writing Device Data from Other Station

(1) Operation When System Switching Occurs Until Tracking Is Completed
When the devices of the control system CPU module where data have been written
are set to within the tracking range, the device data written in the control system CPU
module are also tracked to the standby system CPU module.
However, if system switching occurs due to any of the following reasons from when
write of device data to the control system CPU module is completed until tracking is
completed, the device data written in the control system CPU module are not tracked
to the standby system CPU module.
At this time, the new control system CPU module after system switching uses the old
device data for control.
(2) Checking for system switching after device data write
After writing device data to the control system CPU module by GX Developer or other
means, check for system switching occurrence.
System switching can be checked by either of the following methods.
(a) Checking for system switching by verifying written device data
Specify the control system and write
device data.
Specify the control system and read
the written device data.
Can the data be read normally?
data is consistent with
the written device data?
Diagram 6.41 Flowchart for Checking for System Switching with the Written Device Data
• Control system power off
• Control system CPU module reset
• Control system hardware fault
• Control system CPU module stop error
After write of device data to the control system CPU module is completed, read
the written device data from the control system CPU module to check whether
system switching occurred or not.
Start
NO(Communication failure)
YES(Communication normal)
Are the read device
NO(Inconsistent)
YES(Match)
End
6.5 Precautions for Writing Device Data from Other Station
System switching occurred
Change the connection setup.
System switching occurred
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