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6.2 Redundant System Network Overview
6.2.2 MELSECNET/H Remote I/O network
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(3) Redundant System Operation when a Communication Error Occurs in
the MELSECNET/H Remote I/O Network
(a) System Switching Procedure
When a communication error occurs in the MELSECNET/H remote I/O network,
system switching is performed according to the following procedure, so that the
data link will be continued.
1) When a communication error occurs in the MELSECNET/H remote I/O
network, the control system network module issues a system switching
request to the control system CPU module.
2) When receiving the system switching request from the network module, the
control system CPU module performs END processing. Through the
processing, system switching is performed.
3) After system switching is completed, the new control system network module
continues the data link.