Process Interrupts - Siemens S7-1200 Programming Manualline

3 General Programming

3.8 Process interrupts

3.8 Process interrupts
The processing of the user program can be influenced by events such as process
interrupts. When you need a fast response of the controller to hardware events
(e.g. a rising edge of a channel of a digital input module), configure a process
interrupt. For each process interrupt a separate OB can be programmed. This OB
is called by the operating system of the controller in the event of a process
interrupt. The cycle of the controller is therefore interrupted and continued after
processing the process interrupt.
Figure 3-33: Process interrupt is calling OB
e.g. rising
edge E0.0
Hardware
In the following figure you can see the configuration of a "hardware interrupt" in the
hardware configuration of a digital input module.
Figure 3-34: Configuring hardware interrupt
Advantages
Fast system response to events (rising, falling edge, etc.)
Each event can start a separate OB.
Programming Guideline for S7-1200/1500
V1.2, Entry ID: 81318674
Event
Hardware
interrupt interrupt_1
OB40 OBxxx
e.g. falling
edge E6.1
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