Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 494)

Appendix E
Application Example Programs
E–51
Spray Booth Ladder Program
Rung 2:0
These three rungs read the color information coming from the barcode
decoder outputs and load this into integer N7:4. This color is loaded
into the FIFO when the part carrier actuates the SHIFT LIMIT SWITCH.
| Low Bit | Color |
| from Bar | Select |
| Code | Word |
| Decoder | |
| I:0 N7:4 |
|––––] [–––––––––––––––––––––––––––––––––––––––––––––––––––––( )––––––|
| 2 0 |
Rung 2:1
| Middle Bit | Color |
| from Bar | Select |
| Code | Word |
| Decoder | |
| I:0 N7:4 |
|––––] [–––––––––––––––––––––––––––––––––––––––––––––––––––––( )––––––|
| 3 1 |
Rung 2:2
| High Bit | Color |
| from Bar | Select |
| Code | Word |
| Decoder | |
| I:0 N7:4 |
|––––] [––––––––––––––––––––––––––––––––––––––––––––––––––––––( )–––––|
| 4 2 |
Rung 2:3
When the part carrier actuates the SHIFT LIMIT SWITCH, three things happen
in this rung: (1) the color of the previously painted part is unloaded
from the FIFO to make room for the color of the new part, (2) the color of
the new part is loaded into the FIFO, (3) the presence or absence of a
part on the part carrier is shifted into the Shift Register.
| Shift Unload color |
| Limit of previously |
| Switch painted part |
| |
| I:0 +FFU–––––––––––––––+ |
|––––] [––––––––––––––––––––––––––––––––+–+FIFO UNLOAD +–(EU)–+–|
| 0 | |FIFO #N7:0+–(DN) | |
| | |Dest N7:10+–(EM) | |
| | |Control R6:0| | |
| | |Length 4| | |
| | |Position 4| | |
| | +––––––––––––––––––+ | |
| | Load color of | |
| | new part | |
| | +FFL–––––––––––––––+ | |
| +–+FIFO LOAD +–(EU)–+ |
| | |Source N7:4+–(DN) | |
| | |FIFO #N7:0+–(EM) | |
| | |Control R6:0| | |
| | |Length 4| | |
| | |Position 4| | |
| | +––––––––––––––––––+ | |
| | Load the presence | |
| | of the new part | |
| | | |
| | +BSL–––––––––––––––+ | |
| +–+BIT SHIFT LEFT +–(EU)–+ |
| |File #B3:0+–(DN) |
| |Control R6:1| |
| |Bit Address I:0/1| |
| |Length 4| |
| +––––––––––––––––––+ |