Rockwell Automation 1395 Multi-Comm Hardware/Software - Manual (Page 52)

Chapter 3
Configuration & Interfacing
3–41
The BTW length is determined by adding the message header length (4
words) to the number of words required to specify the parameter list. Each
parameter requested requires two words in the BTW instruction with the
exception of the last parameter in the list. The last parameter requires only
one word. Below are two examples:
Example 1:
The PLC Controller is to read 1 parameter value from the Drive.
Message Header for BTW
BTW BTR Word 3
Message Header 4 4
8 bytes
Parameter Data 1 2 2 bytes
Total 5 words 6 words
10 bytes
Example 2:
The PLC Controller is to read 3 parameter values from the Drive.
Message Header for BTW
BTW BTR Word 3
Message Header 4 4
8 bytes
Parameter Data 5 6 10 bytes
Total 9 words 10 words
18 bytes