Rockwell Automation 1203-EN1 EtherNet/IP-to-SCANport Module - Manual (Page 57)

Using I/O Messaging 5-5
A Datalink is a mechanism used by SCANport drives to transfer data to
and from the controller. Datalinks allow parameter values to be changed
without using an Explicit Message. When enabled, each Datalink
occupies two 16-bit words in both the input and output image.
Rules for Using Datalinks
• Each set of Datalink parameters in a SCANport drive can be used by
only one module. If more than one module is connected to a single
drive, multiple modules must not try to use the same Datalink.
• Parameter settings in the drive determine the data passed through the
Datalink mechanism. For example, the 1305 drive uses Parameter
111 - [Data In A1] and Parameter 119 - [Data Out A1] to configure
the parameter(s) pointed to using Datalink A1. Refer to the
documentation for your drive.
• When you use a Datalink to change a value, the value is not written to
the Non-Volatile Storage (NVS). 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.
The example ladder logic program works with a ControlLogix controller
and a 1305 drive. The example program will also work with a 1336
PLUS II drive.
Function of the Example Program
This example program enables you to:
• Obtain Logic Status information from the drive.
• Use the Logic Command to control the drive (for example, start, stop).
• Send a Reference to the drive and receive Feedback from the drive.
• Send/receive Datalink data to/from the drive.
Using Datalinks
Example Ladder Logic Program