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2 Basic principles of the counter module
Counter Module SIMATIC FM 350-2
V1.0, Item ID: 83146298
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2.5
Operating modes for the channels
2.5.1
Introduction to counting
In the sections below, the following counting functions are explained in greater
detail:
Continuous counting
Single count
Periodic counting
Each time a positive edge is registered by the counter module, the module
increases the value by a count of one. If the count direction "down" is selected,
it decreases the value by one.
Below you can see a diagram with the input signal and the counter reading.
This is an example intended to illustrate that irregular signals can also be present.
In the following chapters, the count will be portrayed using regular signals.
Figure 2–4: Behavior of the counter reading in relation to the input signal