Mitsubishi Electric MELSEC Q Series Reference Manual page 62

(2) Link device behavior when there is a faulty station
(a) Normally operating station
Holds the data received from the faulty station immediately before the error.
(b) Faulty station
Holds the data received from the other stations immediately before the error.
60
Control station
No.1
LB/LW
No.1
send range
No.2
receive range
No.3
receive range
Normal station
Faulty
No.2
station
No.1
receive range
No.2
send range
No.3
receive range
Normal station
No.3
No.1
receive range
No.2
receive range
No.3
send range
Data transferred
Data held