● If the On threshold ≥ Off threshold, then:
Q = 1, if Cnt ≥ On
Q = 0, if Cnt < Off
● If the On threshold < Off threshold, then Q = 1, if On ≤ Cnt ≤ Off.
The system scans the counter limit value cyclically.
Thus, if the pulse frequency at the fast digital inputs I3, I4, I5 or I6 is faster than the cycle
time, the special function might not switch until after the specified limit value is exceeded.
Example: Up to 100 pulses per cycle can be counted; 900 pulses have been counted so
far. On = 950; Off = 10000. The output is set in the next cycle, after the value has
reached 1000. (The output would not be set at all if the value Off = 980).
View in programming mode (example):
To set the start value, press
If the referenced block (B021, in the example) returns a value that lies out of the valid range,
the value is rounded to the next valid value.
The view in parameter assignment mode (example):
Manual, 10/2017, A5E01248535-AA
to access the following screen form:
4.4 Special functions list - SF