Mitsubishi Electric MELSEC iQ-R Series User Manual page 51

Cyclic transmission send/receive processing
When pairing is set for the RJ71LP21-25 of both systems, send data is transferred to the new control system at the time of
system switching to continue cyclic transmission.
The following is the send range of cyclic transmission when pairing is set.
• The own station send ranges of the link devices (LB, LW) of both systems become the same when pairing is set.
• The station operating as the control system sends and receives cyclic data.
• The station operating as the standby system only receives cyclic data.
Each number in the figure, from No.1 to No.4, represents a station number.
No.1
LB0
(1) No.1, No.2
(2) No.3
(3) No.4
LB3FFF
Send range of each station number
(1) From station No.1 as the control system, data in the send ranges of station No.1 and station No.2 are sent to station No.3 and station No.4. If system
switching occurs to due to an error in station No.1, data in the send ranges of stations No.1 and No.2 are sent from station No.2, which starts operating as
the new control system.
(2) Data in the send range of station No.3 is sent to all stations including station No.2 operating as the standby system.
(3) Data in the send range of station No.4 is sent to all stations including station No.2 operating as the standby system.
No.2 No.3
No.1, No.2
No.3 No.3
No.4 No.4
No.4
No.1, No.2
No.3
No.4
1.5 Redundant System Function
1
1 FUNCTIONS
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