The can counting program of Figure 8-9 is described in the text. Prepare an I/O connection diagram and ladder logic program for this process. Use addresses that apply to your PLC. Enter the program into the PLC and prove its operation. Solution I/O connection There three counter instructions CTU-Count Up Counter CTD-Count Down Counter CTUD-Count Up/Down Counter All three count rung transitions Two possible Visualizations : 1st method requires extra programming if timer done status needs to be referenced On other rungs. 2nd method sets a bit with Q which can be referenced by other logic. implementation: cpuchecks I/o module checks scan inputs Execute program Update outputs.

1. The can counting program of Figure 8-9 is described in the text. Prepare an I/O connection
diagram and ladder logic program for this process. Use addresses that apply to your PLC. Enter
the program into the PLC and prove its operation.
Solution
I/O connection
There three counter instructions
CTU-Count Up Counter
CTD-Count Down Counter
CTUD-Count Up/Down Counter
All three count rung transitions
Two possible Visualizations :
1st method requires extra programming if timer done status needs to be referenced
On other rungs.
2nd method sets a bit with Q which can be referenced by other logic.
implementation:
cpuchecks
I/o module checks
scan inputs
Execute program
Update outputs