Redundant Function Processing Time - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

Redundant function processing time

This section describes the redundant function processing time in the Process CPU (redundant mode) or SIL2 Process CPU.
Increase in the scan time due to tracking transfer
The following describes the increase in the scan time of the CPU module due to tracking transfer.
The increase in the scan time determined by the following calculation formula is a rough standard for a system start-up. Check
the increase in the scan time with the actual systems.
The scan time can be checked in SD520 and SD521 (Current scan time). ( Page 850 Fixed scan function
information)
Item
Increase in the scan time of the CPU
module in the control system (Ts)
Increase in the scan time of the CPU
module in the standby system (Tsb)
Ex.
When CTRL is a control system execution program and MAIN is a program executed in both systems
END
processing
Tca
Control system
CPU module
Data reception
completion
Standby system
CPU module
*1 If the constant scan is used, waiting time for the constant scan is generated.
APPX
926
Appendix 9 Processing Time
Increase in the scan time
Ts = Twr + Tst + Tca +  [ms]
Tsb = Taw + Trc [ms]
Scan time of the control system CPU module
I/O
MAIN, CTRL Twr
*1
refresh
Update
completion
I/O
Trc
refresh
END processing
Reference
Twr: Page 927 Waiting time for completion of the previous tracking data
reflection
Tst: Page 927 Tracking data send time
Tca: Page 929 Waiting time for completion of tracking data reception
: Page 929 Other extended times
Taw: Page 929 Waiting time for tracking data reception
Trc: Page 930 Tracking data reflection time
END processing
Ts
Tst
Tracking data
MAIN
Taw
END processing
Scan time of the standby system CPU module
I/O
Tca
*1
refresh
Data reception
completion
Trc
Tsb
Update
completion