Additional Counter Features - Emerson PACSystems RSTi-EP User Manual

User Manual
GFK-2958J
Periodic Counting/ Primary Direction Down
Figure 118: Periodic Counting, Primary Direction Down
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Counting Range
Limits
End value
Upper count limit

Additional Counter Features

You can define the additional features for the counter listed below by parametrizing or via
the process data outputs:
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Detailed Description of I/O Modules
Down-counting starts at the load value.
If the parameterized end value +1 is reached during counting in the negative
direction, the counter jumps back to the load value at the next count pulse and
continues counting from there. The status bit End value reached is set and a process
alarm will be triggered if it is parameterized.
Upon reaching the upper count limit the counter jumps to the lower count limit to
continue counting from there. The status bit Overflow performed is set and a
process alarm will be triggered if it is parameterized. All status bits remain set until
they are reset with the bit Reset status bits in the control word.
Valid range of values
–2 147 483 647 (–2
+2 147 483 647 (–2
Reset: resets the counting value to the load value during counting.
Comparator: Upon meeting the comparison condition, the comparison bit is
activated, or a process alarm is triggered.
Hysteresis: reduces frequent toggling of the comparison bit and/or excessive
triggering of a process alarm, e.g. when the value of a sensor signal fluctuates
around the comparison value. It is possible to count beyond the lower count limit.
) to +2 147 483 647 (2 –1)
31 31
31 –1)
Chapter 5
Oct 2019
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