Mitsubishi Electric MELSEC iQ-R Series - Redundant Function Processing Time

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APPX
Appendix 7 Processing Time
Redundant function processing time
This section describes the processing time in the redundant function.
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 684 Fixed scan function
information)
Ex.
When CTRL is a control system execution program and MAIN is a program executed in both systems (in configuration with
the main base unit only
*2
)
*1 If the constant scan is used, waiting time for the constant scan is generated.
*2 In a redundant system with redundant extension base unit, the processing order in the scan is different ( Page 81 In redundant
mode), but the operation is the same as in a configuration with the main base unit only.
Item Increase in the scan time Reference
Increase in the scan time of the
CPU module in the control
system (Ts)
Ts = Twr + Tst + Tca +  [ms] Twr: Page 725 Waiting time for completion of the previous tracking data reflection (Twr)
Tst: Page 725 Tracking data send time (Tst)
Tca: Page 726 Waiting time for completion of tracking data reception (Tca)
: Page 727 Other extended times ()
Increase in the scan time of the
CPU module in the standby
system (Tsb)
Tsb = Taw + Trc +  [ms] Taw: Page 727 Waiting time for tracking data reception (Taw)
Trc: Page 728 Tracking data reflection time (Trc)
: Page 728 Other extended times ()
MAIN, CTRL Twr Tst Tca
Ts
MAIN
Tca
Trc Taw Trc
Tsb
*1*1
Data reception
completion
Data reception
completion
Update
completion
END processing
END processing
END processing
END
processing
Update
completion
Scan time of the control system CPU module
Control system
CPU module
I/O
refresh
Standby system
CPU module
I/O
refresh
Tracking data
Scan time of the standby system CPU module
I/O
refresh