Siemens SIMATIC ET 200SP Operating Instructions Manual page 148

Interrupts/diagnostic messages
9.6 Hardware interrupts
What is a hardware interrupt?
In accordance with the parameters assigned, the electronic weighing system triggers a
hardware interrupt when certain events or states occur.
When a hardware interrupt occurs, the CPU interrupts execution of the user program and
processes the associated hardware interrupt organization block (OB). The event that triggered
the interrupt is entered in the start information of the assigned hardware interrupt OB by the
CPU.
If different components are dosed into a scale, for example, the hardware interrupts can be
used to achieve maximum accuracy. The electronic weighing system signals, for example, the
hardware interrupt "Coarse flow (incoming)" directly after dosing has started. The
corresponding valve/slider or similar is switched directly in the hardware interrupt OB of the
PLC due to a logical operation from the hardware interrupt information and the address of the
corresponding output. This procedure achieves a high operating speed and therefore accuracy
when dosing multiple components. If only one component is dosed, you should use the digital
outputs of the module to achieve the highest possible reaction speed.
Hardware interrupt lost
If the previous event was not yet processed, "Hardware interrupt lost" is triggered.
See also
Commissioning the electronic weighing system with TIA Portal (Page 38)
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Technology module TM SIWAREX WP351 HF
Operating Instructions, 01/2020, A5E47521010-AA