GE RSTi-EP

Chapter 5 Detailed Descriptions of I/O Modules
GFK-2958E RSTi-EP User Manual 193
Counting Range
Limits
Valid range of values
End value
–2 147 483 647 (–2
31
+ 1) to +2 147 483 647 (2
31
–1)
Lower count limit
+2 147 483 648 (–2
31
)
Periodic Counting/ Primary Direction Down
Periodic Counting, Primary Direction Down
• Down-counting starts at the load value.
• If the parameterised 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 parameterised. All status bits remain set until they are reset with the bit Reset
status bits in the control word.
Counting Range
Limits
Valid range of values
End value
–2 147 483 647 (–2
31
) to +2 147 483 647 (2
31
–1)
Upper count limit
+2 147 483 647 (–2
31
–1)
5.15.3 Additional Counter Features
You can define the additional features for the counter listed below by parametrising or via the
process data outputs:
• 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.