Siemens SIMATIC ET 200MP User Manual page 57

Calculating the response time
It is necessary to differentiate between two cases when calculating the response time of the
IM 155-5 PN HF:
● Case 1: The configured update time is greater than/equal to the backplane bus cycle
time.
Then:
Response time in μs = backplane bus cycle time + configured update time
● Case 2: The configured update time is less than the backplane bus cycle time.
Then:
Response time in μs = backplane bus cycle time + (configured update time x (backplane
bus cycle time / configured update time)).
If the division of backplane bus cycle time / configured update time does not return an
integer without remainder, an additional configured update time must be added next to
the integer in the bracket.
Example calculation for case 1: The configured update time is greater than/equal to the backplane
bus cycle time.
● Configured update time is, for example, 750 μs
● Backplane bus cycle time = 510 μs
Result of case 1
Response time of the IM 155-5 PN HF = 750 μs + 510 μs = 1260 μs
Example calculation for case 2: The configured update time is less than the backplane bus cycle time.
● Configured update time is, for example, 500 μs
● Backplane bus cycle time = 510 μs
Result of case 2
Response time of the IM 155-5 PN HF = 510 μs + (500 μs x (510 μs / 500 μs) + 500 μs) =
510 μs + (500 μs x 1 + 500 μs) = 510 μs + 1000 μs = 1510 μs
Reference
Additional information about performance measurements is available on the Internet
(http://support.automation.siemens.com/WW/view/en/34677186/136000&cspltfrm=0&cssw=0
&csbinh=5).
IM 155-5 PN HF Interface Module (6ES7155-5AA00-0AC0)
Manual, 10/2018, A5E32840985-AB
Response times
B.1 Response times of the ET 200MP
57