Configuring Event/Period Measurement Operating Mode - Siemens SIMATIC S7-1500 System Manual

7.9.7

Configuring event/period measurement operating mode

Event/period duration measurement
Event counter
You use event measurement (16-bit value) to measure the number of rising edges per
application cycle over the feedback interface.
The event counter is a rotary counter.
● An event counter overflow is not displayed.
● The exact value must be calculated on the basis of the difference.
Period measurement
You use the period duration measurement (32-bit value) to measure the number of
increments of 41.67 ns between the last two rising edges received in the application cycle
over the feedback interface.
Period = 41.67 ns • number of increments
Note
Isochronous mode
Event/period measurement requires isochronous mode.
1. Select the the required channel for the Event/period measurement operating mode.
Figure 7-24 Event/period duration measurement
Inversion
You can invert the 24 V signal to adjust it to your process. By default, the signal is not
inverted.
Input delay
To suppress faults, you can set an input delay of 1 µs or 125 µs for the input filter of the
digital inputs. Changes to the signal are only detected if they are constantly pending for
longer than the set input delay time.
To allow signals pending very briefly to be detected at high counting frequencies, you need
to set an input delay of 1 µs.
SIMATIC Drive Controller
System Manual, 11/2019, A5E46600094-AA
7.9 Configuration of digital inputs/outputs (X142)
Configuring
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