Automatic Recovery Of The Cpu Module Of The Standby System - Mitsubishi Electric MELSEC iQ-R Series User Manual

Automatic recovery of the CPU module of the standby system

This function allows the CPU module of the standby system to automatically recover from a specific error ( Page 430
Target errors and operations when the automatic recovery is enabled) that occurs in the CPU module of the standby system.
(Manual operation (turning off and on or resetting the system) is not required to recover the system.)
This function is valid in the backup mode. This function is invalid in a redundant system without extension
base units.
Target errors and operations when the automatic recovery is enabled
The following describes the target of automatic recovery and the operation at automatic recovery setting.
Target error
Tracking Communication Error at
Startup
Extension cable error on the active
side (between the extension base
units)
• If automatic recovery fails and the cause is eliminated, automatic recovery is not performed again by this
function. Therefore, recover the standby system by manual operation (turning off and on or resetting the
system). ( Page 431 Cause of failure of automatic recovery)
• The event is registered when automatic recovery is performed or fails. Therefore, whether automatic
recovery has been executed or failed can be checked in the event history.
When a tracking communication error occurs at system start-up
Tracking communication cannot be performed during the initial processing of the CPU module that was turned on first when
the redundant system starts up. Therefore, a tracking communication error may occur to the CPU module that was turned on
later. If "Tracking communication error at startup" is set to "Automatically recover" for the CPU parameter, when a stop error of
a tracking communication error occurs in the CPU module of the standby system, the standby system is automatically
recovered.
26 REDUNDANT FUNCTION
430
26.9 Settings for Redundant System with Redundant Extension Base Unit
Operation
If the standby system fails to start up due to any of the following causes, the
standby system automatically recovers and both systems can be operated.
• One of the systems is turned off and on before both systems start up.
• The other system is turned on before the first system starts up.
• It took a long time to start up the standby system. (Such as when automatic
restoration or boot operation takes a long time or SD memory card diagnosis is
executed)
If an error occurs in the extension cable (between extension base units) on the
active side, the new standby system automatically recovers and both systems can
be operated.
Reference
Page 430 When a tracking
communication error occurs at
system start-up
Page 431 When an extension cable
error occurs during system
operation