Rockwell Automation 20-COMM-D DeviceNet Adapter Series B FRN 2.xxx User Manual

Page 94

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5-10

Using the I/O

20-COMM-D DeviceNet Adapter User Manual

Publication 20COMM-UM002G-EN-P

PowerFlex 700S, PowerFlex 700L with 700S Control, PowerFlex 753/755, and
PowerFlex Digital DC Drives

Datalinks require scaling in the following way. Parameters are either 16-bit
or 32-bit integers or REALs. When the parameter is a 32-bit integer, the
data needs to be copied using a COP command to a DINT tag. (Because
PLC-5 and SLC 500 controllers do not support 32-bit integers, the data
must be separated into two 16-bit integers.) When the parameter is a REAL,
the data needs to be copied using a COP command to a REAL tag. See
subsequent sections in this chapter for ladder logic examples. See the drive
documentation to determine if the Datalink parameter is a 16-bit or 32-bit
integer parameter, or a REAL parameter.

Using 16-Bit Datalinks to Read/Write 32-Bit Parameters

This subsection only pertains to PowerFlex 70 (standard or enhanced
control), PowerFlex 700 (standard control), and PowerFlex 700H drives
which use 16-bit Datalinks. To read or write a 32-bit parameter using 16-bit
Datalinks, typically both Datalinks of a pair (A, B, C, D) are set to the same
32-bit parameter. For example, to read parameter 10 - [Elapsed Run Time]
in a PowerFlex 70 drive, both Datalink A1 Out (Parameter 310) and
Datalink A2 Out (Parameter 311) are set to ‘10’. Datalink A1 Out will
contain the least significant word (LSW) and Datalink A2 Out will contain
the most significant word (MSW).

32-bit data is stored in binary as follows:

In this example, the parameter 10 - [Elapsed Run Time] value of 6553.9 Hrs
is read as ‘6553.9’ in Datalink A1 Out (Parameter 310) and Datalink A2
Out (Parameter 311).

Conversion Example:

Parameter 010 - [Elapsed Run Time]

= 6553.9 Hrs

MSW = 0001

hex

= 0001

binary

= 2

16

= 65536

LSW = 0003

hex

=3

Engineering Value = 65536 + 3 = 65539
Parameter 10 Displayed Value = 6553.9 Hrs

MSW

2

31

through 2

16

LSW

2

15

through 2

0

Datalink

Word

Parameter

Data (Hex)

A1 Out

LSW

10

0003

A2 Out

MSW

10

0001

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