Interrupt-Driven Program Processing - Siemens SIMATIC S5-95F Manual

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S5-95F
Delay time of the DI module
Execution of
OB 13
OB13 call-up interval
Input signal changes;
signal change is not
recognized
Figure 7-14. Response Time with Time-Controlled Program Processing
Under worst-case conditions, the following applies for the response time with time-controlled
program processing and programmed direct access:
T
OB13 response
With direct access to the onboard I/Os you will obtain the shortest response time. If you have
programmed neither OB2/OB3 interrupts nor direct access to external I/Os, then the response time
for onboard I/Os with direct access is as follows:
T
20 ms + OB13 call-up interval + OB13 execution time.
OB13 response
7.4.6

Interrupt-Driven Program Processing

Interrupt-driven program processing is initiated when a signal from the process causes the CPU to
interrupt cyclic or time-controlled program processing and to execute a specific program. When this
program has been scanned, the CPU returns to the point of interruption in the cyclic or time-
controlled program and continues scanning at that point. For detailed information on interrupt
processing please refer to Chapter 12.
EWA 4NEB 812 6210-02
Variable delay time
Input signal
change is
recognized
1 x OB13 call-up interval
+
OB13 processing delay (max. one OB13 call-up interval)
+
OB13 execution time plus 1 data cycle, if the S5-95F is provided with
external I/Os and 1 data cycle, if direct access to the external I/Os has
been programmed in OB13 (max. one OB13 call-up interval)
+
Delay time of the input module
Variable delay time
Execution of
OB 13
t
T
OB13
OB13 call-up interval
Reaction to input signal
change in the case of
direct access
Introduction to STEP 5
t
7-29

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