1747-6.22, Backup Scanner User Manual

7-130 RIO Block Transfer
Publication 1747-6.22
Rung 2:0
Configure the BTR operation type, length and RIO address at power-up. Bit b3:100/7 must be set prior to going to ru
to indicate a BTR operation.
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| 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 therefore will impact the overall
processor scan time.
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| BTR |
| PENDING BTR STATUS |
| B3 +COP---------------+ |
|-+----] [-----+------------------------------------------+COPY FILE +-
| | 80 | |Source #M1:1.100| |
| | | |Dest #B3:0| |
| | | |Length 4| |
| | | +±±±±±±±±±±±±±±±±±±+ |
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| | CHECK BTR | |
| | STATUS | |
| | B3 | |
| +----] [-----+ |
| 81 |
Rung 2:2
When the error or done bit is set indicating that the BTR completed either unsuccessfully or successfully, the enable
bit must be unlatched by the ladder program. The 1747-SN scanner then unlatches the error/done bit to complete
the block transfer hand-shake process at this time the "check BTR status" bit must be unlatched to avoid
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| unnecessary M-file accesses.
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| VIRTUAL |
| BTR DONE CHECK BTR |
| BIT STATUS |
| B3 B3 |
|-+----]/[-----+-------------------------------------------------------(U)-----
| | 13 | 81 |
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| | VIRTUAL | |
| | BT ERROR | |
| | BIT | |
| | B3 | |
| +----]/[-----+ |
| 12 |