Rockwell Automation 20-COMM-I Interbus Adapter - Manual (Page 55)

Using I/O Messaging 5-5
32-Bit Parameters using 16-Bit Datalinks
To read (and/or write) a 32-bit parameter using 16-bit Datalinks,
typically both Datalinks (x1 and x2) are set to the 32-bit parameter. For
example, to read Parameter 09 - [Elapsed MWh] in a PowerFlex 70,
both Datalink A1 and A2 are set to “9”. Datalink A1 will contain the
least significant word (LSW) and Datalink A2 the most significant word
(MSW). In this example, the parameter 9 value of 5.8MWh is read as a
“58” in Datalink A1.
Regardless of the Datalink combination, x1 will always contain the LSW
and x2 will always contain the MSW. In the following examples
Parameter 242 - [Power Up Marker] contains a value of 88.4541
hours.
32-bit data is stored in binary as follows:
Example:
Parameter 242 - [Power Up Marker] = 88.4541 hours
MSW = 13
decimal
= 1101
binary
= 2
19
+ 2
18
+ 2
16
= 851968
LSW = 32573
851968 + 32573 = 884541
Datalink Most/Least Significant Word Parameter Data (decimal)
A1 LSW 9 58
A2 MSW 9 0
Datalink Most/Least Significant Word Parameter Data (decimal)
A1 LSW 242 32573
A2 - Not Used - 0 0
Datalink Most/Least Significant Word Parameter Data (decimal)
A1 - Not Used - 0 0
A2 MSW 242 13
Datalink Most/Least Significant Word Parameter Data (decimal)
A2 MSW 242 13
B1 LSW 242 32573
MSW 2 31 through 2 16
LSW 2 15 through 2 0
20COMM-UM007A-EN-P.book Page 5 Tuesday, January 22, 2002 10:52 AM