Rockwell Automation 1747-SN Remote I/O Scanner - Manual (Page 137)

Publication 1747-UM013B-EN-P - January 2005
Block Transfer Examples for Earlier Processors D-9
Directional Repeating Block Transfer Example
The following example shows a directional repeating block transfer.
This means that block transfer reads will be sent repeatedly, as fast as
possible. Use the same method for a BTW.
Rung 2:5
BLOCK TRANSFER READS WILL EXECUTE CONTINUOUSLY AS LONG AS THE BTR PRECONDITION
BIT IS TRUE.
| | | | |
| | | | |
| BTR PRE- |VIRTUAL |VIRTUAL |VIRTUAL |
| CONDITION |BTR ENABLE|BTR DONE |BT ERROR BTR |
| BIT |BIT |BIT |BIT PENDING |
| B3 B3 B3 B3 B3 |
|----] [--------]/[--------]/[--------]/[-----------------------+----(L)-----+-|
| 83 1615 13 12 | 80 | |
| | | |
| | | |
| | | |
| | | |
| | VIRTUAL | |
| | BTR ENABLE | |
| | BIT | |
| | B3 | |
| +----(L)-----+ |
| 1615 |
Rung 2:6
MOVE THE VIRTUAL CONTROL WORD TO THE M0 FILE FOR THE SN MODULE WHILE A BTR IS
IN PROGRESS, AND CONTINUE DOING SO UNTIL THE ENABLE, DONE AND ERROR BITS ARE
ALL TURNED OFF, COMPLETING THE HAND-SHAKE PROCESS.
| |
| |
| VIRTUAL BTR |
| BTR ENABLE CONTROL |
| BIT WORD |
| B3 +MOV---------------+ |
|-+----] [-----+------------------------------------------+MOVE +-|
| | 1615 | |Source B3:100| |
| | | | 0000000000000000| |
| | | |Dest M0:1.100| |
| | | | *| |
| | | +------------------+ |
| | | |
| | | |
| | VIRTUAL | |
| | BTR DONE | |
| | BIT | |
| | B3 | |
| +----] [-----+ |
| | 13 | |
| | | |
| | | |
| | VIRTUAL | |
| | BT ERROR | |
| | BIT | |
| | B3 | |
| +----] [-----+ |
| 12 |
Rung 2:7
| |
|-------------------------------------+END+------------------------------------|
| |