Rockwell Automation GMLC Reference Manual - Manual (Page 762)

Publication GMLC-5.2 - November 1999
Using Block Transfers 725
32-bit Signed BCD Format
When received by the motion controller, the two words representing each
value are concatenated into the original 8-digit value. This number is then
converted to a floating-point value by dividing by:
10
(Number of Decimal Digits)
This means that the values to be sent to the motion controller must be
multiplied by this value before being stored in the BTW data file. Failure
to do so results in the transfer of incorrect values to the motion controller.
With 32-bit Signed BCD numeric format, the largest value that can be
represented is ±79,999,999. The number of decimal digits specified for
the transfer also limits the largest values that can be sent to the motion
controller. The following table shows the factor by which the values in the
PLC must be multiplied before being stored in the data file as well as the
corresponding maximum representable values in the motion controller.
RIO Adapter Block Transfer Write
32-bit Signed Data File Format
Word Description
0
1
2 Data Type
First Data Item
Number and Format of Items: 2
dnn
3
4 First Data Item Value MSW
First Data Item Value LSW
5
6 Second Data Item Value MSW
Second Data Item Value LSW
2 nn+1
2 nn+2
Last Data Item Value MSW
Last Data Item Value LSW
2 nn+3 End-of-Block Delimiter (000D hex)