Mitsubishi QJ71LP21 Reference Manual page 189

7 APPLICATION FUNCTIONS
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(d) The intelligent function modules such as QJ71C24, QJ71E71 which are
mounted to the remote I/O stations can access the station that is currently
performing master operation in the MELSEC communication protocol.
Access Destination
Multiplexed remote master station
(Station No. 0)
Multiplexed remote sub-master station
Master operating station
(e) The outputs of the remote I/O stations are held while master operation is
being switched from the multiplexed remote master station to the
multiplexed remote sub-master station.
Multiplexed remote
master station
Remote I/O station Remote I/O station
Multiplexed remote
master station
Master operation
After switching, outputs are cleared.
Remote I/O station Remote I/O station
POINT
Start up the multiplexed remote sub-master station last (after the data link of the
multiplexed remote master station and remote I/O stations is established).
To start from a data link using the multiplexed remote master station independently
of the startup order, do not set Total stations and Setup common in the parameters
of the multiplexed remote sub-master station.
REMARK
The multiplexed remote master station and multiplexed remote sub-master station
cannot be mounted together on a single PLC CPU.
Target Station Number to Be Set
7D
H
Multiplexed remote sub-master station No.
7E
H
Multiplexed remote
sub-master station
Master operation
Remote I/O station
Multiplexed remote master station returns to system
Multiplexed remote
sub-master station
Sub-master operation
Information
transfer
Remote I/O station
MELSEC-Q
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