Configuration Of The Monitoring Times; Calculating The Minimum I/O Retention Time; Premium For The Monitoring Times Of Redundant I/O; Max. Blocking Time For Priority Classes > 15 - Siemens SIMATIC S7-400H Manual

Table 6-2
ET200M: standard output modules
ET200M: HART output modules
ET200M: fail-safe output modules
ET200L-SC with analog output modules
ET200S with analog output modules or technology modules
Perform the following steps:
• Determine the premium form the table. If several module types in the table are
used in Redundant mode, take the highest premium.
• Add it to the monitoring times already determined.

Configuration of the monitoring times

When configuring the monitoring times you must note the following dependencies;
conformity will be checked by STEP 7:
max. scan–cycle time extension
> max. communication delay
> (max. blocking time for priority classes > 15)
> min. I/O retention time
If, in the case of link-up and update with master/standby switch-over, the CPUs
have been configured with different values for a monitoring function then the higher
of the two values will be used.
Calculating the minimum I/O retention time (T
The following applies to the calculation of the minimum I/O retention time:
• with central I/O: T
• with distributed I/O: T
where T
With the use of central and distributed I/O the resulting minimum I/O retention time
is:
= MAX (30 ms, 3 × T
T
PH
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07

Premium for the monitoring times of redundant I/O

Module type
= 30 ms
PH
= 3 × T
PH
= maximum target rotation time
TRmax
of all DP master systems of the fault-tolerant station
)
TRmax
Linking and Synchronizing
)
PH
TRmax
Premium in ms
2
10
50
≤ 80
≤ 20
6-19