Eaton easyE4

6. Function blocks
6.1 Manufacturer function blocks
The mark-to-space ratio is 1:1.
The signals of channels A and B must be offset by 90°. Otherwise the count direction
cannot be determined.
Positive count direction
If the rising edge at channel A is detected before the rising edge at channel B, the
counter will count up. This means that the counter will be incremented by 1 after
there is a rising edge at channel A followed by a rising edge at channel B. The same
applies to the falling edges in sequence at channel A and channel B. The counter
relay's result will be incremented and output at output QV.
Fig. 174: CI function block counting up; QV=QV+4
Negative count direction
If the rising edge at channel B is detected before the rising edge at channel A, the
counter will count up. This means that the counter will be decremented by 1 after
there is a rising edge at channel B followed by a rising edge at channel A. The same
applies to the falling edges in sequence at channel B and channel A. The counter
relay's result will be decremented and output at output QV.
Fig. 175: CI function block counting down; QV=QV-4
NOTICE
Avoid unforeseeable switching states.
Switch C, CF, CH, CI function blocks only at one single point in the pro-
gram.
Otherwise, previous counts will be overwritten.
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