When A Multiplexed Remote I/O Network For The Redundant System Does Not Operate Normally - Mitsubishi QJ71LP21 Reference Manual

8 TROUBLESHOOTING
8.2.7 When a multiplexed remote I/O network for the redundant system does not operate
normally
Check item
Isn't the power supply module of the standby
system turned off?
Hasn't a stop error occurred on the QnPRHCPU of
the standby system?
Hasn't a stop error occurred on the network
module mounted on the main base unit of the
standby system?
Check item
Hasn't an error occurred on a remote I/O station of
function of version C or older?
Check item
Is the send range of the host a tracking range?
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(1) QnPRHCPU will not perform system switching even when the data
link cable is disconnected.
Confirm the status of the external power supply of the standby system.
Connect GX Developer to the QnPRHCPU of the standby system and execute PLC
diagnostics to check if any error has occurred.
Confirm the operation status of the network module of the standby system.
(2) Errors on a remote I/O station cannot be detected by the PLC CPU
of the master operation station.
Check the product information of the network module of the remote I/O station by the
system monitor of GX Developer.
(3) Cyclic data are turned off continuously or instantaneously when
system switching is performed on QnPRHCPU.
Confirm if the devices in the send range of the host is set as tracking devices with the
parameters of GX Developer.
Checking procedure
Checking procedure
Checking procedure
MELSEC-Q
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