Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 118)

Publication 1747-UM010B-EN-P - September 2003
7-6 RIO Block Transfer
Scanner I/O Image Allocation For Block Transfer
Block transfer operations (BTR and BTW) consume only one byte of
the RIO scanner’s I/O image file, independent of what type of I/O slot
addressing is used. This one byte image is reserved for
communication “handshake” purposes between the remote device
(adapter or intelligent I/O module) and the scanner. SLC control
programs must never read/write to these image locations because
unpredictable operations may result.
Block transfer operations (BTR and BTW) can be addressed to any
logical slot within the RIO scanner’s four logical racks. See the
examples on the following page.
You use an M0 file BT control buffer to
initiate a BT. The corresponding M1 file
displays the status of the block transfer.
BT buffers reside on 100 word boundaries
in the M0/M1 files starting at word 100.
For example, BT buffer 1 resides at
M0:e.100 and M1:e.100; BT buffer 2 resides
at M0:e200 and M1:e.200; while BT buffer
16 resides at M0:e.1600 and M1:e.1600.
Note that the "e" in these examples refers
to the physical chassis slot number in
which the scanner resides.
All block transfer buffers (M0 and M1) are
cleared (set to zero) either when the RIO
scanner goes through a power cycle or
when the SLC processor commands the
scanner to change mode from Program to
Test mode, Program to Run mode, or Test
to Run mode.
M0 Control Buffers 1...32
M0:e.100 M0:e.3200
Words
100...109
Words
110...173
3 words for
control and
7 reserved
64 words for
BT Write Data
Words
3200...3209
Words
3210...3273
3 words for
control and 7
reserved
64 words for
BT Write Data
M1 Status Buffers 1...32
Words
100...109
Words
110..173
4 words for
status and 6
reserved
64 words for
BT Read Data
M1:e.100 M1:e.3200
4 words for
status and 6
reserved
64 words for
BT Read Data
Words
3200...3209
Words
3210...3273