GE RSTi-EP - Page 176

Chapter 5 Detailed Descriptions of I/O Modules
GFK-2958E RSTi-EP User Manual 172
• Down-counting starts at the load value.
• If the parametrerized 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 ist set and a process alarm will be
triggered if it is parameterised.
• 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 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
–2 147 483 648 (–2
31
) to +2 147 483 647 (2
31
– 2)
Upper count limit
+2 147 483 647 (2
31
-1)
Periodic Counting/ No Primary Direction
Periodic Counting, No Primary Direction
• Counting (up or down) starts at the load value, the entire counting range is used.
• Upon reaching a count limit, the counter jumps to the load value and starts counting again
from there. The status bit Overflow performed or Underflow 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.