Rockwell Automation 1395 ControlNet Communication Board - Manual (Page 34)

3–20 Configuration & PLC Interfacing
Publication 1395–5.37– March, 1999
The PMW 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 PMW
instruction with the exception of the last parameter in the list. The last
parameter requires only one word. Below is an example:
Example 1:
The PLC Controller is to read 1 parameter value from the Drive.
Message Header for BTW
PMW PMR Word 3
Message Header 4 4
8 bytes
Parameter Data 1 2 2 bytes
Total 5 words 6 words
10 bytes