8
TROUBLESHOOTING
8.1 Troubleshooting Flow
8.1.16 When "CAN'T SWITCH" Occurs to Control System CPU Module due to Communication Error when
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8.1.16 When "CAN'T SWITCH" Occurs to Control System CPU Module due
to Communication Error when Turning ON/OFF Power Supply of
CPU Module or Booting and Shutting Down Personal Computer in
CC-Link IE Controller Network or MELSECNET/H
(1) Cause of "CAN'T SWITCH" occurrence
In the redundant system where CC-Link IE Controller Network or MELSECNET/H is
used, CC-Link IE Controller Network or MELSECNET/H module of the control system
may issue a switching request, detecting a communication error due to turning power
supply ON/OFF of the other station (including the standby system) CPU module or
booting and shutting down the personal computer where CC-Link IE Controller
Network interface board or MELSECNET/H board is mounted.
For details of function requesting to switch system to the control system CPU module,
refer to the following manuals.
CC-Link IE Controller Network Reference Manual
Q Corresponding MELSECNET/H Network System Reference Manual
(PLC to PLC network)
Q Corresponding MELSECNET/H Network System Reference Manual
(Remote I/O network)
Note that "CAN'T SWITCH" may be detected in the control system CPU module when
the above-mentioned system switching is requested before the control system of the
redundant system is started up. Although the control system operates normally even
in this case, how to cancel "CAN'T SWITCH" is shown below.