Rockwell Automation DeviceLogix System User Manual - Manual (Page 42)

42 Publication RA-UM003B-EN-P - February 2010
Chapter 2 Navigate the Function Block Editor Interface
Up Counter
The Up Counter has two inputs called Input and Reset and one output
called Output. The Up counter simply counts up on a FALSE to TRUE
transition and sets its output to TRUE when the accumulator reaches
the preset value. The accumulator continues to count up until the
counter is reset or it reaches 65,535. A TRUE value on the reset input
zeros the accumulator and sets the output to FALSE.
An illustration of the counter function with a preset value set to 3 is
below.
The valid data ranges are as follows.
Up/Down Counter
The Up/Down counter has three inputs called Input, Reset, and Count
Down Input and one output called Output. The counter increments
the accumulator any time the Input changes from FALSE to TRUE and
decrements the counter any time the Count Down Input changes from
FALSE to TRUE. When the accumulator is above or equal to the preset
value, the counter sets its output to TRUE. When the accumulator falls
below the preset, the counter resets its output to FALSE. Like the Up
Counter, the Up Down Counter resets when a TRUE level is detected
on the Reset input. When a reset occurs, the counter zeros the
accumulator and sets the output to FALSE.
Parameters Data Range
PRE 0 ~ 65535
ACC 0 ~ 65535