Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 119)

Publication 1747-UM010B-EN-P - September 2003
RIO Block Transfer 7-7
Examples of BT I/O Image File Allocation
Example 1
1747-SN RIO Scanner’s I/O Image Files
Logical
Rack 0
Logical
Rack 3
Input Image Output Image
Logical Slot 0
Logical Slot 1
The minimum portion of the scanner’s image that
can be assigned to an adapter is 1/4-logical rack.
Each logical device that you assign BT operations
(BTR or BTW) consumes one byte from the
scanner’s input and output image file. The one
byte can come from either the low" byte (Logical
Slot 0) or the high" byte (Logical Slot 1). Logical
Slot 1 only applies for 2 slot addressing.
In this example there are two block transfer
operations mapped to the scanner’s I/O image.
One BT operation is mapped to Logical Rack 0,
Logical Group 4, Logical Slot 1. The other is
mapped to Logical Rack 3, Logical Group 4, Logical
Slot 0.
TIP
The logical address of your RIO
devices (i.e., adapter and
intelligent I/O modules)
determine where the block
transfer gets mapped.
Group 0
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Group 7
Group 0
Group 1
Group 7
Group 0
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Group 7
Word 0
Word 1
Word 2
Word 3
Word 4
Word 5
Word 6
Word 7
Word 8
Word 9
Word 23
Word 24
Word 25
Word 26
Word 27
Word 28
Word 29
Word 30
Word 31