Mitsubishi MELSEC Q Series User Manual page 25

1 OVERVIEW
Data link control by the master station
Master station
Data link
control in
progress
Cyclic communication
Master station is down
Master station
Cyclic communication
1 - 7
(8) Data link status setting when the master station PLC CPU has an
error
The data-link status can be set to either "stop" or "continue" when an error
causing the operation to stop such as "SP. UNIT ERROR" occurs in the PLC
CPU at the master station. With errors enabling the operation to continue such as
"BATTERY ERROR," the data link will continue regardless of the setting (see
Section 4.3.3).
(9) Setting the status of input data from a data link faulty station
The data entered (received) from a data-link faulty station can be cleared or the
previous status immediately before the error can be maintained (see Section
4.3.4).
(10) 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 due to a malfunction of the PLC CPU or power supply.
The master station can return to online even during data link control by the
standby master station, and prepares itself for standby master station system
down (see Section 4.3.6).
Remote device station
Station number 2
Number of occupied stations: 2
Data link control by the standby master station
Remote device station
Station number 2
Number of occupied stations: 2
Intelligent device station
Station number 4
Number of occupied stations: 1
Cyclic communication
Intelligent device station
Station number 4
Number of occupied stations: 1
Cyclic communication
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MELSEC-Q
Standby master station
Station number 1
Number of occupied stations: 1
Standby
Cyclic communication
Standby master station
Station number 1
Data link
control in
progress
Cyclic communication
0
1 - 7