Standby Master Function - Mitsubishi Electric M800VW Series Programming Manual

M800V/M80V Series PLC Programming Manual (2/2)
16 External PLC link
16.1 CC-Link

16.1.4 Standby Master Function

This function enables the data link to continue working by switching to a standby master station (backup station for the master
station) if a malfunction occurs in the master station.
The master station can return to online even during data link controlled by the standby master station, and prepares itself for
standby master station's system down. (Master station duplex function)
NC can function both as a master station and a standby master station.
Controlling: Controls data link in CC-Link system
Waiting: Stands by for failure of the station controlling data link CC-Link system
Data link is controlled by the master station
Master station
Controlling
Cyclic communication
Master station is down -> The standby master station controls data link
Master station
Cyclic communication
Master station returns to normal and comes back online ->
Master station prepares itself for standby master station's failure
Master station
*2
Station No.0 -> 1 Occupies 1 station
Waiting
Cyclic communication
*1 When data link control is transferred to standby master station at the master station's
system down, the station No. of the standby master station is changed to "0".
*2 When master station comes back online as a standby master station, the master station's
No. changes to the one set in the network parameter "Standby master station No.".
Remote device station
Station No.2 : Occupies 2 stations
Cyclic communication
Remote device station
Station No.2 : Occupies 2 stations
Cyclic communication
Remote device station
Station No.2 : Occupies 2 stations
Cyclic communication
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Intelligent device station
Station No.4 : Occupies 1 station
Cyclic communication
Intelligent device station
Station No.4 : Occupies 1 station
Cyclic communication
Intelligent device station
Station No.4 : Occupies 1 station
Cyclic communication
Standby master station
Station No.1 : Occupies 1 station
Waiting
Standby master station
*1
Station No.1 -> 0
Controlling
Standby master station
Station No.0
Controlling
IB-1501668-B