Mitsubishi Electric MELSEC Q Series Reference Manual page 262

7 APPLICATION FUNCTIONS
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(4) Communication among multiplexed remote master station,
multiplexed remote sub-master station and remote I/O stations
(a) The input (X) data of the remote I/O station and the link relay (B) and link
register (W) data sent by the remote I/O station are transferred to both the
multiplexed remote master station and multiplexed remote sub-master
station.
(b) The output (Y) data of the remote I/O station and the link relay (B) and link
register (W) data received by the remote I/O station are normally controlled
by the multiplexed remote master station. When the multiplexed remote
master station fails, the multiplexed remote sub-master station controls the
data.
(c) Between the multiplexed remote master station and multiplexed remote
sub-master station, data are transferred using X/Y/B/W to ensure that the
multiplexed remote sub-master station can control the remote I/O station
continuously when the multiplexed remote master station fails.
• LX/LY data flow between stations
Multiplexed remote master station
(master operation)
LX LY
0
1FFF
Multiplexed remote master station
LX LY
0
1FFF
Multiplexed remote sub-master station
(sub-master operation)
(c) Data transfer
(a)
(b)
(a)
LX LY
7FF
Remote I/O station
Multiplexed remote master station fails
Multiplexed remote sub-master station
(master operation)
LX LY
7FF
Remote I/O station
MELSEC-Q
LX LY
0
1FFF
LX LY
0
1FFF
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