Siemens SIMATIC PCS 7 CPU 410-5H System Manual page 131

8. Based on the formula [1]:
T
= 1200 ms - (2 x 8 ms + 300 ms + 50 ms + 110 ms + 20 ms) = 704 ms
Check: Since T
1. T
2. Based on the formula [2]:
T
P15_OD
Check: Since T
1. Based on section Performance values for link-up and update (Page 133) with 170 KB of
user program data:
T
Check: Since T
1. Based on formula [3], we obtain the recommended max. inhibit time for priority
classes > 15:
T
P15
T
P15
This means that by setting a maximum inhibit time of 194 ms for priority classes > 15 in
STEP 7, you ensure that any signal changes during the update are detected with a signal
duration of 1250 ms or 1200 ms.
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
(IO subsystem)
P15
> 0, continue with
P15
= MIN (720 ms, 660 ms, 704 ms) = 660 ms
P15_HW
= 50 ms + T = 50 ms + 90 ms = 140 ms
PH
= 140 ms < T
P15_OD
= 194 ms
P15_AWP
= 194 ms < T
P15_AWP
= MAX (194 ms, 140 ms)
= 194 ms
= 660 ms, continue with
P15_HW
= 660 ms, continue with
P15_HW
Link-up and update
8.3 Time monitoring
131