Mitsubishi Electric MELSEC iQ-R Series User Manual page 731

Time required for system switching
The following describes the time required for the CPU module in the new control system to start operating as the new control
system after the detection of a system switching cause in the control system.
The time required for system switching determined by the following calculation formula is a rough standard for a system start-
up. Check the time with the actual systems.
Tsw = Trd + Trc + Tcs [ms]
• Tsw: Time required for system switching
• Trd: Delay until the CPU module in the standby system receives the system switching request sent from the control system
• Trc: Time required for reflection of tracking data in the CPU module of the standby system
• Tcs: Setup time required for the CPU module in the standby system to start operating as the new control system
*1 This is the maximum system switching time.
Cause of system switching has been detected.
Control system
System A
Trd
Standby system
System B
Trc
Tsw
System switching cause
*2
• Power supply module failure , power-off
• Reset
• CPU module failure
*3
• Base unit failure
• CPU module stop error (major)
• Redundant function module failure
*5
CPU module stop error (moderate)
System switching request from a network
module
System switching request by the
SP.CONTSW instruction
System switching request from the
engineering tool
*1 The standby system scan time is the total of "Execution time of the standby system program after a system switching cause is received
+ Tracking data reflection time".
*2 The systems may not be switched when the CC-Link IE Field Network module has not been mounted, when the extension base unit for
the redundant system is not being used, or depending on the state of the power supply module failure. To switch the systems regardless
of the state of the power supply module failure, mount the CC-Link IE Field Network module or use the extension base unit for the
redundant system. Note, in this case, that Trd is determined by the following:
 Via the CC-Link IE Field Network module: Trd = 400ms (maximum) + Standby system scan time
 Via the redundant extension base unit: Trd = 57.5ms (maximum)
*1
Standby system
Control system
Tcs
Processing time per each system switching cause
Trd
■When the standby system scan time is longer
*1
than 19.26ms
0.517 + Standby system scan time - 19.26 [ms]
■When the standby system scan time is 19.26ms
*1
or shorter
0.517ms
■When the standby system scan time is longer
*1
than 10ms
0.517 + Standby system scan time - 10 [ms]
*3
■When the standby system scan time is 10ms or
*1
shorter
0.517ms
Increase in the scan time of the CPU module in the
control system (Ts) by tracking transfer
time for completion of the previous tracking data
reflection (Twr)
Increase in the scan time of the CPU module in the
control system (Ts) by tracking transfer - Waiting
time for completion of the previous tracking data
reflection (Twr)
Trc Tcs
0ms 1ms
Page 730
5ms
*4
- Waiting Tracking data
reflection time
*4
(Trc)
Page 730
Tracking data
reflection time
(Trc)
Appendix 7 Processing Time
The following time is added
according to the parameter
setting and system
configuration.
• When the signal flow
memory is tracked: 0ms
• When the signal flow
memory is not tracked: 2ms
• When an extension base
unit for the redundant
system is used: 5.8ms
• When a fault occurs in the
extension cable: 2.5ms
APPX
729
A