Rockwell Automation 1746-HSCE,D17466.5 High-Speed Counter Module - Manual (Page 26)

Publication 1746-UM006B-EN-P - August 2005
2-8 Module Operation
Ring Counter
The figure below demonstrates ring counter operation. In ring counter
operation, the count value goes between 0 and a maximum value.
The maximum value must be entered in the Maximum Count Value
(M0:e.34 Range and Rate Mode, M0:e.41 Sequencer Mode).
The ring counter automatically rolls over to 0 if the count exceeds the
maximum value. If the count goes below 0 it rolls over to the
maximum value. The ring counter always resets to zero.
IMPORTANT
If the reset value is nonzero, there is a delay of up to
500 µs before the reset value is loaded. Count pulses
can be lost if they happen during the delay time.
Refer to Timing Information in Appendix A.
Count Up Count Down
Rollover
1 32,767