What is NI SoftMotion and SoftMotion Drive Interface?
The LabVIEW SoftMotion Module enhances LabVIEW by adding the capabilities to control motors and drives using high-level commands and develop custom motion applications using NI real-time and FPGA. With NI SoftMotion, you can use a LabVIEW project to configure all of your motion axis settings, test your configuration, tune your motors, and quickly integrate custom motion control into your application. By pairing NI SoftMotion with a real-time operating system and FPGA on NI embedded controllers like PXI RT, Industrial Controller, and CompactRIO, you can easily synchronize multiple motion axes with I/O, Vision, HMI, and other functions.
The SoftMotion Drive Interface (SDI) is the solution National Instruments developed to standardize communication with third-party EtherCAT motor drives. Conventional communication with an EtherCAT-capable motor drive is done by reading and writing commands to PDO and SDO memory registers on a drive. The SDI takes care of this low-level communication to PDO and SDO registers for you, and allows you to focus on the high-level control aspects of your application using the SoftMotion API. SDI Plug-ins contain all the necessary components to add the EtherCAT drive to your LabVIEW Project and control the drive using SoftMotion.
You can download SDI Plug-ins from the LabVIEW Tools Network. The SDI framework was introduced with SoftMotion 2014 SP1 and newer, although some plug-ins require later versions of LabVIEW and SoftMotion. Plug-ins install as VI Packages through the VI Package Manager. SDI Plug-ins are hosted on the LabVIEW Tools Network, and the currently supported list of NI's Drive Partners is below.
Note: VI Package Manager must be installed to install plug-ins. The Minimum Software Set Version applies to LabVIEW and the LabVIEW SoftMotion Module. For full compatibility notes, see the related link below.
Traditionally, integrating a third-party EtherCAT motor drive into control software is a process of learning the correct PDO/SDO data registers, the data requirements for these registers, and when to communicate with them from code. Despite most EtherCAT-capable drives conforming to the CiA 402 standard, many operational behaviors differ between drive vendor implementations of CiA 402. These differences have presented a challenge to integrators that have expressed time and again, the need for a unified interface to reduce development time and cost.
National Instruments provides a unified command framework called the SoftMotion Drive Interface as a solution to this issue. The SoftMotion Drive Interface (SDI) enables you to easily work with third-party EtherCAT motor drives in SoftMotion by installing Plug-ins for third-party drives. These Plug-ins are built to translate high-level move and configuration commands into the necessary communication to a third-party drive. Instead of learning which PDO a user needs to send a command to, the user can simply send a command using the hardware-agnostic functions provided by the NI SoftMotion Module in LabVIEW.
Since the functions provided by NI SoftMotion are hardware-agnostic, the same LabVIEW control code can be re-used with a variety of different hardware with little to no change to the code. Integrators can use the SoftMotion Drive Interface as a method for developing code that can work with any hardware for which a SDI Plug-in is available.
The table above lists the EtherCAT motor drives compatible with SDI. Only the single-axis variant of each drive is supported.
SDI also requires the use of a controller that supports EtherCAT and LabVIEW Real-Time. This includes CompactRIO, CompactDAQ, PXI, and Industrial Controllers with LabVIEW Real-Time. For a more comprehensive list, see this product support page.
Contact your local NI Sales Representative here. If the drive you are working with does not have a SDI Plug-in yet, we want to know! This is valuable information we can use to make our products and capabilities better.