Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 381

7 APPLICATION FUNCTIONS
1
System A
scan time
Data sent from
station No. 1 to
0)
other station
System A
Control system
Standby system
System B
System B
scan time
Data sent from station
No. 2 to other station
Other station's
data received
from station
No. 1 or 2
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(2) Cyclic data retention time for a control system CPU stop error,
execution of a system switching instruction, system switching
operation from GX Developer, or system switching requesting from
other network module
Use the following expression to calculate the cyclic data retention time in the
case of a control system CPU stop error, execution of a system switching
instruction, system switching operation from GX Developer, and system
switching requesting from other network module.
[Cyclic data retention time (T
T = Tsw + SS [ms]
H
Tsw : Redundant CPU system switching time [ms]
SS : Redundant CPU scan time [ms]
Execution of system
switching instruction
2
1)
Standby system
Cyclic transmission
delay time
1)
0)
Cyclic data retention time
)]
H
Control system
System switching time
3
2)
Cyclic transmission
delay time
2)
MELSEC-Q
4 5
3) 4)
3) 4)
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