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6.2 Redundant System Network Overview
6.2.2 MELSECNET/H Remote I/O network
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6.2.2 MELSECNET/H Remote I/O network
A redundant system uses a multiplexed remote I/O system of MELSECNET/H remote I/O
network to continue the control of remote I/O stations even when system switching occurs.
The multiplexed remote I/O network system consists of "multiplexed remote master
station" that controls remote I/O stations, and "multiplexed remote sub-master stations"
that is for backup of multiplexed remote master station.
In a redundant system, make sure to set system A as the multiplexed remote master
station, and system B as the multiplexed remote sub-master station.
(1) Overview of Remote I/O Stations
The control system network module (multiplexed remote master station) performs
data control with remote I/O station by data transmission, and data transmission with
the multiplexed remote sub-master station.
The standby system network module (multiplexed remote sub-master station)
receives data from remote I/O stations and sends/receives data to/from the
multiplexed remote master station in order to take over the control of remote I/O
stations even when system switching occurs.
Diagram 6.13 Overview of Remote I/O Station
Send and receive data
Receive data
Remote I/O station
Remote I/O station
Remote I/O station
System A -
Control System
System B -
Standby System
Receive data from the remote I/O
station and send/receive data with
the remote master station.
Multiplexed
Remote
Sub-master Station
Control based on data received with
the remote station, and receive data
with the remote sub-master station.
Multiplexed Remote Master Station
MELSECNET/H
Remote I/O network
Q35B
Q35B
Q35B
Q35B
Q35B