Allen-Bradley 1747-SN - Bidirectional Continuous Block Transfer Example

5–38 RIO Block Transfer
Publication 17476.6 - July 1996
Bidirectional Continuous Block Transfer Example
The following rungs demonstrate a bidirectional continuous block
transfer. The BTR and BTW will each execute as fast as possible,
continuously and independently of one another.
Rung 2:0
CONFIGURE THE BT OPERATION TYPE, LENGTH AND RIO ADDRESS (R,G,S IN DECIMAL) AT
POWER–UP. BIT N7:50/7 MUST BE SET TO A ”1” TO INDICATE A BTR AND BIT N7:53/7
MUST BE A LOGICAL ”0” TO INDICATE A BTW OPERATION.
| |
| |
| |
| POWER–UP BTR |
| BIT CONTROL |
| S:1 +COP–––––––––––––––+ |
|––––] [––––––––––––––––––––––––––––––––––––––––––––––+–+COPY FILE +–+–|
| 15 | |Source #N7:50| | |
| | |Dest #M0:1.100| | |
| | |Length 3| | |
| | +––––––––––––––––––+ | |
| | | |
| | | |
| | | |
| | BTW | |
| | CONTROL | |
| | +COP–––––––––––––––+ | |
| +–+COPY FILE +–+ |
| |Source #N7:53| |
| |Dest #M0:1.200| |
| |Length 3| |
| +––––––––––––––––––+ |
Rung 2:1
COPY THE BTR STATUS AREA TO AN INTEGER FILE ONLY WHEN A BTR IS IN PROGRESS.
THIS STATUS INFORMATION WILL THEN BE USED THROUGHOUT THE PROGRAM AND WILL LIMIT
THE NUMBER OF M–FILE ACCESSES.
| |
| |
| |
| BTR |
| PENDING BTR STATUS |
| B3 +COP–––––––––––––––+ |
|–+––––] [–––––+––––––––––––––––––––––––––––––––––––––––––+COPY FILE +–|
| | 0 | |Source #M1:1.100| |
| | | |Dest #N7:60| |
| | | |Length 4| |
| | | +––––––––––––––––––+ |
| | | |
| | | |
| | | |
| | CHECK BTR | |
| | STATUS | |
| | B3 | |
| +––––] [–––––+ |
| 2 |
Rung 2:2
UNLATCH THE BIT THAT CONTINUES TO CHECK THE BTR STATUS. WHEN A BTR IS
COMPLETE, THE DONE OR ERROR BIT IS SET. THE LADDER PROGRAM MUST THEN UNLATCH
THE ENABLE BIT, THEN WAIT FOR THE SN MODULE TO TURN OFF THE DONE/ERROR BIT
BEFORE ANOTHER BTR TO THE SAME M–FILE LOCATION CAN BE INITIATED. THIS IS ONE
COMPLETE BTR CYCLE.
| |
| |
| VIRTUAL |
| BTR DONE CHECK BTR |
| BIT STATUS |
| N7:60 B3 |
|–+––––]/[–––––+–––––––––––––––––––––––––––––––––––––––––––––––––––––––(U)–––––|
| | 13 | 2 |
| | | |
| | | |
| | VIRTUAL | |
| | BTR ERROR | |
| | BIT | |
| | N7:60 | |
| +––––]/[–––––+ |
| 12 |