Rockwell Automation 20-COMM-E PowerFlex EtherNet/IP Adapter - Manual (Page 101)

Using the I/O 5-9
20-COMM-E EtherNet/IP Adapter User Manual
Publication 20COMM-UM010G-EN-P
Using Datalinks
A Datalink is a mechanism used by PowerFlex drives to transfer data to and
from the controller. Datalinks allow a drive parameter value to be read or
written without using an Explicit Message. When enabled, each Datalink
occupies two 16-bit or 32-bit words in both the input and output image. Use
adapter Parameter 19 - [Datalink Size] to determine whether the drive
uses 16-bit or 32-bit words for Datalinks.
Rules for Using Datalinks
• Each set of Datalink parameters in a PowerFlex drive can be used by
only one adapter. If more than one adapter is connected to a single drive,
multiple adapters cannot use the same Datalink.
• Parameter settings in the drive determine the data passed through the
Datalink mechanism. See the documentation for your drive.
• When you use a Datalink to change a value, the value is not written to
the Nonvolatile Storage (NVS) memory. The value is stored in volatile
memory and lost when the drive loses power. Thus, use Datalinks when
you need to change a value of a parameter frequently.
Datalink Scaling
PowerFlex 70/700/700H Drives and PowerFlex 700L Drives with 700 Control
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, SLC 500, or
MicroLogix 1100/1400 controller—Datalink scaling is not automatic and
uses whole numbers (INTs or DINTs). See the drive documentation to
determine the unit resolution for the associated parameter Datalink. For
example, PowerFlex 700VC drive parameter 3 - [Output Current] has a 0.1
unit resolution. Because Datalink scaling uses whole numbers, the Output
Current value is multiplied by 10 in the adapter and then sent over the
network. Suppose the actual Output Current value is 35.5 amps. Reading the
associated parameter Datalink received by the controller, the value would be
355. By using ladder logic, divide the value by 10 in the controller to get the
correct scaling. See the drive documentation to determine if the Datalink
parameter is a 16-bit or 32-bit parameter.
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, SLC 500, or
MicroLogix 1100/1400 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, SLC 500, and MicroLogix