1747-6.22, Backup Scanner User Manual

7-124 RIO Block Transfer
Rung 2:0
| |
| |
|
POWER±UP BTR |
| BIT CONTROL |
| S:1 +COP---------------+ |
|-+----] [-----+------------------------------------------+COPY FILE |
| 15 |Source #B3:100| |
|
|Dest #M0:1.100| |
| |Length 3| |
| +------------------+ |
Rung 2:1
Copy the BTR status area to a binary file which will be used throughout the program. This avoids addressing the M1 file multiple times
during each program scan. Each time an instruction containing an M1 file bit, word or file is scanned by the processor, an immediate
data transfer to the module occurs and will impact the overall processor scan time.
| SERVICE |
| THE BTR |
| STATUS/ |
| BTR |
| PENDING BTR STATUS |
| B3:5 +COP---------------+ |
|-+----] [-----+------------------------------------------+COPY FILE |
| 0 |Source #M1:1.100| |
|
| | |Dest #B3:0| |
| | | |Length 4| |
| | | +------------------+ |
| | CHECK BTR | |
| | STATUS | |
| | UNTIL DN | |
| | OR ER BIT | |
| | IS OFF | |
| | B3:5 | |
| +----] [-----+ |
| 1 |
Rung 2:2
| | | CHECK BTR |
| | | STATUS |
| | VIRTUAL | UNTIL DN |
| | BTR DONE | OR ER BIT |
| | BIT | IS OFF |
| B3:0 B3:5 |
|----]/[-------------------------------------------------------------(U)--------
| 13 1
|
| |
| | VIRTUAL |
| | BTR ERROR |
| | BIT |
| | B3:0 |
| +----]/[-----+
| 12
Publication 1747-6.22
Block Transfer Read Control Logic Example
Configure the BTR operation type, length and rio address at power-up. Bit b3:100/7 must be set prior to run to
indicate a BTR operation.
Unlatch the bit that continues to check the btr status. When a BTR is complete, the done bit is set. The ladder program must then
unlatch the enable bit, then wait for the SN module to turn off the done bit before another BTR to the same M-file location can be initiate
This is one complete BTR cycle.