Setting Up A Block Transfer - Allen-Bradley 1747-SN User Manual

Setting Up a Block
Transfer
Follow the steps below to set up your scanner and SLC control
program for either BTWs or BTRs.
1. To use the BT functionality, you must increase the size of the M0
and M1 files in an offline APS session. The size depends on the
number of BT buffers your applications requires. Note that
setting the buffers to maximum size (3300) will not affect system
performance. However, addressing M-files in your SLC control
program does affect system performance.
2. Set the control flags in M0:e.x00. Where x = block transfer
buffer number. See the tables below for read/write settings.
If You Want to Transfer
Data:
To the scanner from the
adapter
From the scanner to the
adapter
If You Want to specify a:
BTR (Block Transfer Read)
BTW (Block Transfer Write)
3. Specify the length of the data you wish to block transfer in word
M0:e.x01. Note that maximum length is 64 words.
4. Specify the device's logical rack, group, and slot in word
M0:e.x02.
5. Set up your SLC control program to set the EN bit.
RIO Block Transfer
Use:
BTR (Block Transfer Read)
BTW (Block Transfer Write)
Do this to the M0:e.x00/7 file :
Set the bit to 1 to specify a read operation
Set the bit to 0 to specify a write operation.
Publication 1747 6.6 - July 1996
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