Allen-Bradley 1747-SN - Page 152

7–19Application Examples
Publication 17476.6 - July 1996
Rung 2:5
If a BTR errors, unlatch the BTR enable bit and the BTR pending bit. In addition,
the BTR error code (N7:63 OR M1:1.103) must be viewed or buffered to determine the
cause of the error.
| SERVICE |
| THE BTR |
| STATUS/ |
| BTR ERROR BTR |
| BIT PENDING |
| N7:60 B3:0 |
|––––] [––––––––––––––––––––––––––––––––––––––––––––––––––––––––+––––(U)–––––+–|
| 12 | 0 | |
| | | |
| | | |
| | | |
| | BTR ENABLE | |
| | BIT | |
| | M0:1.100 | |
| +––––(U)–––––+ |
| 15 |
Rung 2:6
If a BTW errors, unlatch the BTW enable bit and the BTW pending bit. In addition,
the BTW error code (N7:67 OR M1;1.203) must be viewed or buffered to determine the
cause of the error.
| |
| |
| |
| BTW ERROR BTW ENABLE |
| BIT BIT |
| N7:64 M0:1.200 |
|––––] [––––––––––––––––––––––––––––––––––––––––––––––––––––––––+––––(U)–––––+–|
| 12 | 15 | |
| | | |
| | | |
| | SERVICE | |
| | THE BTW | |
| | STATUS/ | |
| | BTW | |
| | PENDING | |
| | B3:0 | |
| +––––(U)–––––+ |
| 1 |
Rung 2:7
Free–running timer to execute a BTR to the analog input in Logical Rack 3, Group 7
left slot every 100ms (0).
| T4:0 +TON–––––––––––––––+ |
|––]/[–––––––––––––––––––––––––––––––––––––––––––––––+TIMER ON DELAY +–(EN)–|
| DN |Timer T4:0+–(DN) |
| |Time Base 0.01| |
| |Preset 10| |
| |Accum 0| |
| +––––––––––––––––––+ |
Rung 2:8
Initiate a BTR every 100ms as long as a BTR is not in progress. A complete cycle
requires that when complete or error, the ladder program unlatches the enable bit
and the scanner then unlatches the done bit. A new BTR must not be initiated until
these conditions occur.
| | SERVICE |
| | THE BTR |
| | STATUS/ |
| BTR ENABLE|BTR DONE BTR |
| BIT |BIT PENDING |
| T4:0 M0:1.100 M1:1.100 B3:0 |
|––] [–––––]/[––––––––]/[–––––––––––––––––––––––––––––––––––––––+––––(L)–––––+–|
| DN 15 13 | 0 | |
| | | |
| | | |
| | | |
| | BTR ENABLE | |
| | BIT | |
| | M0:1.100 | |
| +––––(L)–––––+ |
| 15 |