Real-Time Control Technology Meets the Needs of Real-Time Industrial Communication Developments – Part 3

“Part 1 of this series of technical articles introduces the market opportunity for EtherCAT Slave Stack Solutions for C2000™ Microcontrollers (MCUs) and presents a three-stage guide to getting started with Slave Stack Development. Part 2 details the features and benefits of the TI C2000 MCU EtherCAT implementation. In Part 3, we’ll detail the three stages of developing your own slave node application and describe how the EtherCAT package in TI’s C2000 controlSUITE™ software supports each stage.

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Part 1 of this series of technical articles introduces the market opportunity for EtherCAT Slave Stack Solutions for C2000™ Microcontrollers (MCUs) and presents a three-stage guide to getting started with Slave Stack Development. Part 2 details the features and benefits of the TI C2000 MCU EtherCAT implementation. In Part 3, we’ll detail the three stages of developing your own slave node application and describe how the EtherCAT package in TI’s C2000 controlSUITE™ software supports each stage.

Given that EtherCAT technology and C2000 MCU motion control applications have yet to be supported in software, and customers have made requests in this regard, TI leveraged its embedded software development experience and C2000 MCU architecture knowledge to create a software solution designed to help develop IT The C2000 controls the EtherCAT slave node of the MCU in real time. Packages will help you:

l Evaluate the stack of the slave node.

l Verify proper operation/connection of custom hardware.

l Create a complete slave node application using your hardware and the stack distributed by ETG.

Step 1: Evaluate the C2000 EtherCAT Node (Stack and Hardware)

The first software solutions included in the C2000 EtherCAT Support are designed to quickly and easily familiarize you with the basic solution. With TwinCAT Pc software for EtherCAT master, a simple “echoback” example application, and EtherCAT slaves and the C2000 Delfino MCU controlCARD kit, you can build a multi-node EtherCAT network on your bench in minutes.

The EtherCAT “slave demo” project is a binary image release of the EtherCAT controlCARD, optimized for C28x CPUs including slave stack binary versions. So all you need to do is program the C2000 MCU and connect the CAT5 cable to the EtherCAT master – the TwinCAT PC/PLC.

Figure 1: C2000 MCU out-of-the-box EtherCAT slave demonstration and evaluation solution

This evaluation project will help you answer the following questions: What is the propagation delay from an external EtherCAT controller (ET1100) to the C2000 MCU? What are the central processing unit (CPU) bandwidth requirements for this solution? What is the hardware abstraction layer (HAL) and memory footprint from the stack?

After downloading the latest controlSUITE software, you can install the demo and evaluation examples by executing the setup file “EtherCAT_Slave_Demo_Code_v01_00_00_00_setup” in the controlSUITE development kit project.

Step Two: Verify Your EtherCAT Hardware

The second software solution lets you move from being based on TI controlCARD tools to helping you develop your own hardware. The EtherCAT community refers to the interface of the programmable controller as the Processor Data Interface (PDI).You can find Parallel PDI in the EtherCAT Interface Reference Design for High Performance MCUs, “ASYNC16” (C2000 MCU External Memory Interface[EMIF]) and Serial PDI (C2000 MCU Serial Peripheral Interface[SPI]) reference hardware design. This software project will help you to verify that the hardware interface built “from MCU to wire” is correct.

Since the Hardware Abstraction Layer (HAL) test application (see Figure 2) communicates with the TwinCAT master node, this software project helps you to verify the physical PDI interfaces (EMIF and SPI ports) of an EtherCAT controller (e.g. ET1100), as well as the physical Layer (PHY) and Ethernet are properly connected.

In this case, you do not need a stack of EtherCAT slaves to verify the hardware connection. Unlike in the first step, the HAL test project can be used as source code to help verify or adapt the C2000 MCU to other physical interfaces of the EtherCAT controller.

Figure 2: C2000 MCU HAL test application

Step 3: Create your own EtherCAT slave node solution

Finally, the EtherCAT Application Reference Project provides a step-by-step example when designers need to integrate proven hardware with an EtherCAT stack. This project contains the source code needed to build an example EtherCAT slave node (initialization, HAL, echoback application). The exception is the EtherCAT slave stack itself, which you have to obtain through the EtherCAT Technology Group. It is distributed as part of the Slave Stack Configuration (SSC) tool.

Figure 3: C2000 MCU Native EtherCAT Slave Stack Reference Development Framework

If your version of the configuration tool does not support C2000 MCUs, the controlSUITE project includes a patch that gives you C2000 MCUs (along with ASYNC16 and SPI PDI options) in the drop down processor selection dialog. See the “EtherCAT Solutions Reference Guide” for details on how to insert code using SSC.

There are two project configurations to choose from:

Random-access memory (RAM)-based projects are often useful (less time spent programming flash memory) during the initial stages of a project where code changes are frequent.

l Flash-based projects are often useful when the code is more mature and ready to be tested by power cycling the target C2000 MCU.

By publishing the EtherCAT Slave and C2000 Delfino™ MCU controlCARD kit and EtherCAT solution reference in ControlSUITE software, you can jumpstart the development of EtherCAT slave stacks that run directly on the C2000 MCU.

Other resources

l Download the EtherCATcontrolSUITE software project and design files.

l Purchase C2000 EtherCAT controlCARD.

l Download the “EtherCAT Interface User Guide for High-Performance C2000 MCUs.”

l To learn more about TI’s EtherCAT Slave Node solution for C2000 microcontrollers, visit:

l DesignDRIVE training portal:

l DesignDRIVE application portal.