Allen-Bradley 1747-SN - Page 104

5–27RIO Block Transfer
Publication 17476.6 - July 1996
Rung 2:4
IF A BTW ERRORS, UNLATCH THE ENABLE BIT, THE BTW PENDING BIT AND BUFFER THE BTW
ERROR CODE. ALSO, LATCH THE BIT THAT CONTINUES CHECKING THE BTW STATUS UNTIL
THE SN MODULE TURNS OFF THE ERROR BIT.
| |
| |
| VIRTUAL |
| BTW ERROR BUFFER BTW |
| BIT ERROR CODE |
| B3:0 +MOV–––––––––––––––+ |
|––––] [––––––––––––––––––––––––––––––––––––––––––––––+–+MOVE +–+–|
| 12 | |Source B3:3| | |
| | | 0000000000000000| | |
| | |Dest B3:4| | |
| | | 0000000000000000| | |
| | +––––––––––––––––––+ | |
| | SERVICE | |
| | THE BTW | |
| | STATUS/ | |
| | BTW | |
| | PENDING | |
| | B3:5 | |
| +––––(U)–––––––––––––––+ |
| | 0 | |
| | | |
| | VIRTUAL | |
| | BTW ENABLE | |
| | BIT | |
| | B3:100 | |
| +––––(U)–––––––––––––––+ |
| | 15 | |
| | | |
| | CHECK BTW | |
| | STATUS | |
| | UNTIL DONE | |
| | BIT IS OFF | |
| | B3:5 | |
| +––––(L)–––––––––––––––+ |
| 1 |
Rung 2:5
WHEN USER LOGIC INITIATES A NEW BTW, COPY THE DATA TO THE M0 FILE DATA AREA
AND LATCH THE VIRTUAL BTW ENABLE BIT, PROVIDED THAT A BTW IS NOT IN PROGRESS.
ALSO, LATCH THE BTW PENDING BIT, SO THE BT STATUS FILE WILL BE READ BY THE
LADDER PROGRAM.
| | | | |
| USER LOGIC| | | |
| TO |VIRTUAL |VIRTUAL |VIRTUAL |
| INITIATE A|BTW ENABLE|BTW DONE |BTW ERROR |
| BTW |BIT |BIT |BIT BTW DATA |
| I:2.0 B3:100 B3:0 B3:0 +COP–––––––––––––––+ |
|––––] [––––––––]/[––––––––]/[––––––––]/[–––––––––––––+–+COPY FILE +–+–|
| 0 15 13 12 | |Source #N7:110| | |
| | |Dest #M0:1.110| | |
| | |Length 64| | |
| | +––––––––––––––––––+ | |
| | SERVICE | |
| | THE BTW | |
| | STATUS/ | |
| | BTW | |
| | PENDING | |
| | B3:5 | |
| +––––(L)–––––––––––––––+ |
| | 0 | |
| | | |
| | | |
| | VIRTUAL | |
| | BTW ENABLE | |
| | BIT | |
| | B3:100 | |
| +––––(L)–––––––––––––––+ |
| 15 |