Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 163)

Chapter 9
Using Comparison Instructions
9–12
To demonstrate the use of comparison instructions, this section provides
ladder rungs followed by the optimized instruction list for these rungs. The
rungs are part of the paper drilling machine application example described in
appendix D. You will be adding an instruction to file 2 and beginning a
subroutine in file 7.
Adding to File 2
To begin you will once again need to return to the rungs first entered in
chapter 5 in the program
GETSTART . One more instruction needs to be added
to the first rung to keep track of the drill life. This rung is indicated below
by the shading. Notice that text has also been added to the rung comment.
Important: Do not add this instruction if you are using a 16 I/O controller.
Address O0/6 is only valid for 32 I/O controllers.
Ladder Rung
Rung 2:3
Starts the conveyor in motion when the start button is pressed. However,
there are other conditions that must also be met before we start the
conveyor. They are: the drill must be in its fully retracted position
(home); the drill bit must not be past its maximum useful life. This rung
also stops the conveyor when the stop button is pressed or when the drill
life is exceeded.
| START |Drill STOP |change | Machine |
| Button |Home LS Button |drill bit | RUN |
| |NOW | Latch |
| I:0 I:0 I:0 O:0 B3 |
|–+––––] [––––––––][–––––+––––]/[––––––––]/[––––––––––––––––––( )–––––|
| | 6 5 | 7 6 0 |
| | Machine | |
| | RUN | |
| | Latch | |
| | B3 | |
| +––––] [––––––––––––––––+ |
| 0 |
Comparison Instructions in
the Paper Drilling Machine
Application Example