Rockwell Automation 1769-SM1 Compact I/O to DPI/SCANport Module User Manual
Page 54
4-6
Understanding the I/O Image
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] in a PowerFlex 70 drive contains a
value of 88.4541 hours.
The following example shows an unlike Datalink pair of A2 and B1.
With A1 already assigned, the next two available Datalinks were used.
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
decimal
851968 + 32573 = 884541
Datalink
Most/Least Significant Word
Parameter Data (decimal)
A1
LSW
242
32573
A2
- Not Used -
0
0
A1
- Not Used -
0
0
A2
MSW
242
13
A1
LSW
242
32573
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
Most Significant Word Value
Least Significant Word Value
0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 1
0 1 1 1 1 1 1 1 0 0 1 1 1 1 0 1
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
851968
32573