Siemens SIMATIC ET 200MP Manual page 47

Calculating the response time
It is necessary to differentiate between two cases when calculating the response time of the
IM 155-5 PN ST:
● 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 backplane 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 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 ST = 750 μs + 510 μs = 1260 μs
Example calculation 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 ST = 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
Establishing the PROFINET response time for typical configurations on the PROFINET IO.
A typical PROFINET IO configuration consists of an IO controller with multiple IO devices
that are connected by cable or IWLAN to the IO controller. Additional loads, such as
programming devices (PGs), HMI devices (Panels) or additional S7 stations, can be present
as data receiving stations on the PROFINET line.
You can find the measured values of the PROFINET response time for a typical
configuration in this application example
(https://support.industry.siemens.com/cs/ww/en/view/21869080).
Interface module IM 155-5 PN ST (6ES7155-5AA01-0AB0)
Manual, 11/2017, A5E03612323-AC
Response times
B.1 Response times of the ET 200MP
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