Rockwell Automation 20-COMM-Q ControlNet Adapter User Manual
Page 86
5-12
Using the I/O
20-COMM-C/Q ControlNet Adapter User Manual
Publication 20COMM-UM003F-EN-P
PowerFlex 700S, PowerFlex 700L with 700S Control, PowerFlex 753/755, and
PowerFlex Digital DC Drives
When using RSLogix 5000 software, version 16.00 or later, Datalink
scaling is done automatically. However, when using RSLogix 5000
software, version 15.00 or earlier—or when using a PLC-5 or SLC 500
controller—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