GE PACSystems RX7i - Counters; Data Required for Counter Function Blocks

Chapter 4. Ladder Diagram (LD) Programming
GFK-2950C February 2018 133
4.7 Counters
Function
Mnemonic
Description
Down Counter
DNCTR
Counts down from a preset value. The output is ON whenever the
Current Value is  0.
Up Counter
UPCTR
Counts up to a designated value. The output is ON whenever the
Current Value is  the Preset Value.
4.7.1 Data Required for Counter Function Blocks
Warning
Do not use two consecutive words (registers) as the
starting addresses of two counters. Logic Developer
PLC does not check or warn you if register blocks
overlap. Timers will not work if you place the current
value of a second timer on top of the preset value for
the previous timer.