Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 384)

Preface MicroLogix 1000 Programmable Controllers User Manual
E–34
On/Off Circuit Application Example
The following application example illustrates how to use an input to toggle an
output either on or off. For a detailed explanation of:
•
XIC, XIO, OTE, OTU, OTL, and OSR instructions, see chapter 6.
•
JMP and LBL instructions, see chapter 10.
If the output is off when the input is energized, the output is turned on. If the output
is on when the input is energized, the output is turned off.
On/Off Circuit Ladder Program
Rung 2:0
Does a one-shot from the input push button to an internal bit – the
internal bit is true for only one scan. This prevent toggling of the
physical output in case the push button is held ”ON” for more than one
scan (always the case).
| push button|OSR #1 | push button |
| Input | | false-to- |
| | true |
| I:0 B3 B3 |
|––––] [–––––––[OSR]––––––––––––––––––––––––––––––––––––––––––( )–––––|
| 0 1 0 |
Rung 2:1
If the push button input has gone from false-to-true and the output is
presently OFF, turn the output ON and jump over the following rung to
the rest of the programs. If the JMP instruction was missing, the
following rung would be true and would turn the output back OFF.
|push button|Toggling Toggling |
| false-to- |Output Output |
| true | |
| B3 O:0 O:0 |
|––––] [––––––––]/[––––––––––––––––––––––––––––––––––––+––––(L)–––––+–|
| 0 0 | 0 | |
| | Go to rest | |
| | of program | |
| | | |
| | 1 | |
| +–––(JMP)––––+ |
| |