beautypg.com

Rockwell Automation RECOMM-DNET DeviceNet Adapter for use with DPI AC Drives User Manual

Page 59

background image

Using I/O Messaging

6-5

6.5.2 32-Bit Parameters Using 16-Bit Datalinks

To read (and/or write) a 32-bit parameter using 16-bit Datalinks,
typically both Datalinks (A,B,C,D) are set to the 32-bit parameter.

For example, to read Elapsed MWH (9), 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, Power Up Marker (242) contains a value of 88.4541
hours.

32-bit data is stored in binary as follows:

Example:

Power Up Marker (242) = 88.4541 hours
MSW = 13

decimal

= 1101

binary

= 2

16

+ 2

18

+ 2

19

= 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