Siemens SIMATIC PCS 7 CPU 410-5H System Manual page 297

Monitoring times during link-up and update
Note
If you have made I/O modules redundant and have taken account of this in your program,
you may need to add an overhead to the calculated monitoring times so that no bumps occur
at output modules (in HW Config -> Properties CPU -> H Parameter).
An overhead is only required if you operate modules from the following table as redundant
modules.
Table 15- 8
Module type
ET200M: Standard output modules
ET200M: HART output modules
ET200M: F-output modules
Follow the steps below:
● Calculate the overhead from the table. If you use several module types from the table
redundantly, apply the largest overhead.
● Add this to all of the monitoring times calculated so far.
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
For the monitoring times with redundant I/O
15.14 Other options for connecting redundant I/Os
Overhead in ms
2
10
50
Supplementary information
297