Hardware Interrupts; A.5 Hardware Interrupts - Siemens SIMATIC ET 200SP HA Manual

Drivers, parameters, diagnostics messages and address space

A.5 Hardware interrupts

A.5

Hardware interrupts

Hardware interrupts
The DI 8x24...125VDC HA can trigger hardware interrupts on a signal change of digital inputs.
Interrupt OBs are called automatically if an interrupt occurs.
You can find detailed information on the event in the hardware interrupt organization block
with the "RALRM" instruction (read additional interrupt information).
Evaluate hardware interrupts of digital inputs
On occurrence of the following events the DI 8x24...125VDC HA generates a hardware
interrupt for digital input signals:
● At positive edge (change of signal from 0 to 1)
● At negative edge (change of signal from 1 to 0)
The module digital input (channel) that has triggered the hardware interrupt is entered in
variable OB40_POINT_ADDR in the start information of OB40. The figure below shows the
assignment to the bits of local data double word 8.
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[ID: 91008194059]
Digital input module DI 8x24...125VDC HA (6DL1131-6DF00-0PK0)
Manual, 11/2017, A5E39288633-AB