Rockwell Automation GMLC Reference Manual - Manual (Page 752)

Publication GMLC-5.2 - November 1999
Using Block Transfers 715
For example, to send 10 position values for axis 2, and each in 32-bit
integer format with three digits to the right of the decimal point, and from
the PLC to points 100-109 in the master cam table in the motion
controller:
1. Put 7B23 in word 0 of the BTW data file.
2. Put 0064 (100 decimal = 64 hex) in word 1 of the data file.
3. Put 030A (32-bit integer; 3 decimal digits; 10 decimal = 0A hex
items) in word 2 of the BTW data file.
See detailed information in this chapter on sending or getting each type of
item.
Note: Always specify 01 in the low byte of word 2 of the BTW data
file, when transferring a Data Parameter, Data Bit, or System
Variable.
Up to 60 sequential user variables or cam table points can be transferred
in any one block transfer depending on the numeric format specified for
the transfer. Sequential data parameter, data bit, or system variables can
not be sent to or gotten from the motion controller in one block transfer.
To access multiple items of these types, multiple block transfers are
required.
The following sections explain each of the available numeric formats.
32-bit Integer Format
When the most significant digit of word 2 in the BTW data file is 0,
values are transferred as 32-bit 2s complement integers. In the PLC data
file, each 32-bit value is stored as two contiguous 16-bit integers.
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.