Emerson PACSystems RSTi-EP User Manual page 211

User Manual
GFK-2958J
One-time Counting/ Primary Direction Down
Figure 115: 1-time Counting, Primary Count Down
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•
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Counting Range
Limits
End value
Upper count limit
Periodic Counting/ No Primary Direction
Figure 116: Periodic Counting, No Primary Direction
Detailed Description of I/O Modules
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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. The
internal gate is automatically closed, the status bit End value reached is set and a
process alarm will be triggered if it is parameterized.
To restart counting, the internal gate must be reopened. Counting starts again at
the load value.
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
–2 147 483 648 (–2
+2 147 483 647 (2
31 ) to +2 147 483 647 (2 31 –2)
31 – 1)
Chapter 5
Oct 2019
196