Siemens SIMATIC CPU 410 System Manual page 361

Extending the cycle time
The calculated cycle time of a S7-400H CPU must be multiplied by a CPU-specific factor.
The table below lists these factors:
Table 18- 12 Extending the cycle time
Startup
Factor
Long synchronization cables may increase cycle times. This extension can have the factor 2
- 5 with a cable length of 10 km.
Operating system execution time at the cycle control point
The table below shows the operating system execution time at the cycle checkpoint of the
CPUs.
Table 18- 13 Operating system execution time at the cycle control point
Sequence
Cycle control at the SCCP
Extended cycle time due to nested interrupts
Table 18- 14 Extended cycle time due to nested interrupts
CPU Hardware
interrupt
CPU 410-5H 75 µs
stand-alone
mode
CPU 410-5H 180 µs
redundant
The program runtime at interrupt level must be added to this time extension.
If several interrupts are nested, their times must be added together.
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC
CPU 410-5H stand-alone mode
1.05
CPU 410-5H stand-alone mode
25 - 330 µs
∅ 30 µs
Diagnostic Time-of-
interrupt day inter-
rupt
40 µs 50 µs
70 µs 200 µs
18.16 CPU 410 cycle and reaction times
Delay interrupt Cyclic
inter-
rupt
40 µs 40 µs
120 µs 120 µs
Supplementary information
CPU 410-5H redundant
1.2
CPU 410-5H redundant
120 - 600 µs
∅ 135 µs
Programming I/O
error access
error
20 µs 20 µs
90 µs 45 µs
Asyn-
chronous
error
55 µs
130 µs
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