Shortest Response Time - Siemens SIMATIC ET 200S Manual

Cycle and Response Times

Shortest response time

The following figure shows you the conditions under which the shortest response
time is obtained.
Figure 9-2
Calculation
The (shortest) response time consists of the following:
S 1
process image transfer time for the inputs +
S 1
operating system processing time +
S 1
program scanning time +
S 1
process image transfer time for outputs +
S Delay of the inputs and outputs
This corresponds to the sum of the cycle time and the delay of the inputs and
outputs.
9-6
Delay of the inputs
The status of the observed input changes immediately
PII
before reading in the PII. The change in the input
signal is therefore taken account of in the PII.
Operating
system
The change in the input signal is processed
User
by the user program here.
program
The response of the user program to the input signal
PIQ
change is passed on to the outputs here.
Delay of the outputs
Shortest response time
ET 200S IM 151-7 CPU Interface Module
A5E00058783-04