4.2.2
Direct CPU Connection
This section describes the direct CPU connection by which a GOT is connected to a PLC CPU in the redundant system.
Two methods for the CPU direct connection, using one or two GOTs, are available.
■1. When using one GOT
Monitor target
Control system
(System A)
Network No. 1, Station No. 2
(remote I/O station)
(1) Connection method
Connect the GOT to the RS-232 interface of the control system CPU module (Q12PRHCPU, Q25PRHCPU) of the
redundant system.
For details, refer to the following.
➠
6. DIRECT CONNECTION TO CPU
(2) GT Designer3 setting
Set GT Designer3 as follows.
Setting item
Controller Type
Device setting (Network setting)
MELSEC Redundant Setting
(3) Monitoring target change when system switching occurs in a redundant system
When the system switching occurs, the PLC CPU (other station) of the control system after system switching takes
over the host station operation.
Since the GOT monitors the control system, the monitoring target is automatically changed to other station.
CPU direct connection
GOT
Network No. 1, Station No. 0
(Multiplexed remote master station)
MELSECNET/H remote I/O network
MELSEC-Q/QS, Q17nD/M/NC/DR, CRnD-700
Host
➠
4.3 MELSEC Redundant Setting
POINT
POINT
POINT
To monitor the control system without MELSEC redundant setting
If the system switching occurs when the MELSEC redundant setting is not made, the GOT
cannot change the monitoring target at the occurrence of system switching since it monitors the
connected PLC CPU (host station).
As a countermeasure, change the cable connection from the PLC CPU in the previous control
system to the control system after system switching.
Network No. 1, Station No. 1
(Multiplexed remote sub master station)
Settings
4.2 MELSEC Q Series
4
Standby system
(System B)
Model
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