Rockwell Automation GMLC Reference Manual - Manual (Page 770)

Publication GMLC-5.2 - November 1999
Using Block Transfers 733
If the PLC is sending data to the motion controller, the remainder of the
BTW data file (words 3 through 2nn+2, where nn is the number of items
to be sent) contains the values of the specified items, and the last word
(word 2nn+3) is the end-of-block delimiter, as shown below.
If the PLC is getting data from the motion controller, no item values need
be specified in the BTW data file and thus the end-of-block delimiter is
word 3 (nn = 0). The returned data is stored in the integer (N) file
specified in the BTR. After completing the BTR, this file contains the
returned values, as shown below.
RIO Adapter Block Transfer Write
Word-Swapped 32-bit Integer Data File Format
Word Description
0
1
2 Data Type
First Data Item
Number and Format of Items: 4
dnn
3
4 First Data Item Value Least Significant Word
First Data Item Value Most Significant Word
5
6 Second Data Item Value Least Significant Word
Second Data Item Value Most Significant Word
2 nn+1
2 nn+2
Last Data Item Value Least Significant Word
Last Data Item Value Most Significant Word
2 nn+3 End-of-Block Delimiter (000D hex)
RIO Adapter Block Transfer Read
Word-Swapped 32-bit Integer Returned Values Data File Format
Word Description
0
1 First Data Item Value Least Significant Word
First Data Item Value Most Significant Word
2
3 Second Data Item Value Least Significant Word
Second Data Item Value Most Significant Word
…
…+1 Next Data Item Value Least Significant Word
Next Data Item Value Most Significant Word