Event-Driven Program Execution; Response Time Of The Cpus When Program Execution Is Event-Controlled - Siemens Simatic S7-1500 Function Manual

Event-driven program execution

4.1 Response time of the CPUs when program execution is event-
controlled
Introduction
Hardware interrupts are used to detect events in the process in the user program and to
react to them with an appropriate program. In STEP 7, the organization blocks OB 40 to
OB 47 are intended for processing hardware alarms. You can create additional hardware
interrupts starting with organization block OB 123. The number of available organization
blocks depends on the CPU used.
Hardware interrupt
A hardware interrupt is an interrupt that occurs during the running program execution, due to
an interrupt-triggering process event. The operating system calls the assigned interrupt OB;
as a result, the execution of the program cycle or of lower priority program parts is
interrupted. A hardware interrupt OB is assigned to the "Hardware interrupt" event class.
Cycle and response times
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