Owner's manual

16 Rockwell Automation Publication 1756-UM536A-EN-P - April 2012
Chapter 2 Module Operation
Up/Down Count Function
The Up/Down Count function causes a counter to increment or decrement
accumulated count or changes the direction bit for frequency values.
To invoke the Up/Down Count function for a counter by using the hardware
input method, tie the function to a hardware input on the Input Configuration
tab of the Module Properties dialog box as shown in Figure 3
.
Figure 3 - Up/Down Count Function Controlled by Hardware Input
When tied to a hardware input, this function is level-sensitive resulting in a
change of status when the input is either low or high:
• By default, the count direction goes up when the input is low and down
when the input is high.
• When the function is inverted, the count direction goes up when an input
is high and down when the input is low.
Up/Down Count function for counter 1
is tied to hardware input 3.