System Switching Operation - Mitsubishi Electric MELSEC iQ-R Series User Manual

System switching operation

The send range of cyclic transmission of both systems is as follows:
• The own station send range of the link devices (RY, RWw) of both systems is the same due to pairing.
• The remote head module of the control system sends and receives cyclic data.
• The remote head module of the standby system only receives cyclic data.
When an error occurs in the control system, the control switches to the standby system to continue the system operations.
This section describes the system switching operation of the remote head module for the redundant slave station with single
line.
For the system switching operation when the remote head module is redundant with single line and redundant master station,
or with redundant line, refer to the following.
 MELSEC iQ-R CC-Link IE Field Network User's Manual (Application)
Before system switching operation
The remote head module of the control system performs I/O refresh with the module on the base unit.
The remote head module of the standby system receives data from the master station and inputs from the module on the base
unit. However, it does not send data to the master station and does not output to a module on the base unit.
Each number in the figure, from No.0 to No.2, represents a station number.
No.0
Master station
RX, RWr
No.1, 2
No.3
Ò
RY, RWw
No.1, 2
No.3
: Send range of station No.
: Send data from the master station
: Send data from the slave station
: Send and receive data of external device
 The redundant remote head modules have serialized station numbers. Based on the pairing setting of the master station, the devices (RX, RY, RWr, RWw)
of both stations are set as identical.
 Only the control system sends data to the master station.
 Both the control system and the standby system receive data from the master station.
 Both the control system and standby system perform input from the I/O module.
 Only the control system performs output to the I/O module.
1 FUNCTIONS
46
1.8 Redundant Function
No.1
Remote head module
(control system)
RX, RWr
Ó
No.1, 2
RY, RWw
Ô
No.1, 2
No.2
Remote head module I/O module
(standby system)
RX, RWr
No.1, 2
Õ
RY, RWw
No.1, 2
Ö
No.3
Remote head module
RX, RWr
No.3
RY, RWw
No.3