Hardware Interrupts - Siemens SIMATIC ET 200SP Manual

5.3

Hardware interrupts

Introduction
For the technology module, you can configure which events are to trigger a hardware
interrupt during operation.
What is a hardware interrupt?
The technology module will trigger a hardware interrupt as configured in response to specific
events/states. When a hardware interrupt occurs, the CPU interrupts execution of the user
program and processes the assigned hardware interrupt OB. The event that triggered the
interrupt is entered in the start information of the assigned hardware interrupt OB by the
CPU.
Lost hardware interrupt
If an event occurs that is to trigger a hardware interrupt and the preceding event has not yet
been processed, another hardware interrupt cannot be triggered. The hardware interrupt is
lost and the diagnostic interrupt "Lost hardware interrupt" is triggered.
Enabling of hardware interrupts
A hardware interrupt is triggered when the condition for the change of the respective status
or event bit in the feedback interface is met.
You enable the hardware interrupts in the device configuration with the basic parameters.
You can configure hardware interrupts to be triggered for the following event types:
● Opening of internal gate (gate start)
● Closing of internal gate (gate stop)
● Overflow (high counting limit violated)
● Underflow (low counting limit violated)
● Comparison event for DQ0 has occurred
● Comparison event for DQ1 has occurred
● Zero crossing
● New Capture value available
● Synchronization of the counter by an external signal
● Direction reversal
Only configurable in Counting mode
1
Feedback bit STS_DIR is preassigned with "0". If the first counter value change occurs in
2
the
interrupt is triggered.
When the "Zero crossing" hardware interrupt is enabled, for system-related reasons it can
3
also be triggered if "0" is outside the configured value range.
TM Count 1x24V (6ES7138‑6AA01‑0BA0) technology module
Manual, 07/2019, A5E33002339-AD
3
2
downwards direction
directly after switching on the technology module, no hardware
1
Interrupts/diagnostic messages
5.3 Hardware interrupts
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