Rockwell Automation 1747-SN Remote I/O Scanner - Manual (Page 80)

Publication 1747-UM013B-EN-P - January 2005
5-2 RIO Block Transfer
RIO Block Transfer Theory of Operation - Path of Block Transfer
RIO Block Transfer Theory of Operation - Block Transfer Read (BTR)
RIO
Scanner SLC
Processor
I/O
Image
M Files
Chassis Backplane
RIO Link
= path of a Block Transfer (BT)
Adapter or
Intelligent
I/O Module
M
Files
(SLC 5/02 or
above)
Refer to the diagrams on the following pages for
more details on BTR and BTW sequence of
operation.
Block Transfer Write (BTW) data travels from the
SLC processor across the chassis backplane via
the scanner’s M files. The scanner then sends
the data across the RIO link to the adapter or
intelligent I/O module.
Block Transfer Read (BTR) data travels from the
adapter or intelligent I/O module over the RIO
link to the scanner. The chassis backplane then
transfers BTR data via the scanner’s M files to
the SLC processor. The SLC control program
processes the data once the SLC receives it from
the scanner.
1747 RIO
Scanner
I/O
Image
Chassis Backplane
Adapter or
Intelligent
I/O Module
RIO Link
= path of the BTR
Word 8
Word 9
Word 7
Word 5
Word 6
Word 3
Word 4
Word 1
Word 2
Word 0
Logical
Rack 0
Word 26
Word 27
Word 25
Word 30
Word 28
Word 29
Word 31
Logical
Rack 3
Input Image Output Image
In this example, Logical Rack 0, Logical Group 0, Logical Slot 1 is used.
M1 file
M0 file
One byte is consumed from the
input and output image file for
handshake purposes.
Group 0
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Group 7
Group 0
Group 1
Word 24
Word 23
Group 0
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Group 7
Group 7
Slot 0
Slot 1
Slot 0
Slot 1
SLC 5/02
Processor
(or later)
M
Files