Rockwell Automation 1771-TCM,D17716.5.108 TEMPERATURE CONTROL MOD - Manual (Page 119)

Appendix C
Example Ladder Logic Program
C-27
Wed Jun 1, 1994 Page 21
Program Listing Report PLC–5/40 File TCM Rung 42:10
Rung 42:10
Any time the TCM BTW function is in its ”quiescent” state, the following five
rungs will compare the DYC words from the PLC–5 data table with the same words
that were loaded into the TCM BTW data file (B24:74 – B24:137) upon conclusion
of the last successful BTW to TCM (reference the logic in Program File #045).
The subsequent two rungs will force a DYC download if a change is found.
| SEARCH |
| TCM DYC |
| WORD FILE |
| FOR CHANGE |
| R23:0 |
+–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––(RES)––––+
| |
Rung 42:11
| ERROR |
| PERFORMING |
| TCM DYC |
| WORD FILE |
| SEARCH |
| R23:0 |
+––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––(U)–––––+
| ER |
Rung 42:12
| TCM DYC |
| WORD FILE |
| SEARCH |
| INHIBITED |
| R23:0 |
+––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––(U)–––––+
| IN |
Rung 42:13
| CHANGE FND |
| DURING |
| TCM DYC |
| WORD FILE |
| SEARCH |
| R23:0 |
+––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––(U)–––––+
| FD |
Rung 42:14
| SEARCH |
| TCM DYC |
| WORD FILE |
| FOR CHANGE |
| +FSC––––––––––––––––––––+ |
+–––––––––––––––––––––––––––––––––––––––––––––––+FILE SEARCH/COMPARE +–(EN)–+
| |Control R23:0| |
| |Length 64+–(DN) |
| |Position 0| |
| |Mode ALL+–(ER) |
| |Expression | |
| |#N39:1 <> #B24:74 | |
| +–––––––––––––––––––––––+ |