Real-time control technology to meet the needs of real-time industrial communication development – Part 1

In my previous blog post, “EtherCAT and C2000 MCUs – Real-Time Communication Meets Real-Time Control,” I discussed a design in the TI Designs reference design library to help simplify International Electrotechnical Commission (IEC) 61158 compliant and TI C2000-based Hardware development for EtherCAT slave nodes that control microcontrollers (MCUs) in real time. This blog post outlines why EtherCAT technology is ideal for C2000 MCUs in industrial automation applications, and why the TI DesignDRIVE team chose Beckhoff’s ET1100 as a reference. The EtherCAT Interface for High-Performance MCU Reference Design does not provide a way to evaluate and create a complete EtherCAT node (including stack) on your own.

With the release of the EtherCAT Slave and C2000 Delfino MCU controlCARD kit and EtherCAT solution reference software in controlSUITE, you can jumpstart the development of EtherCAT slave stacks directly on the C2000 MCU.

In the next blog series, I’ll discuss the market opportunities for EtherCAT slave stack support on C2000 MCUs; how TI’s implementation is different; and then dive into how to support evaluation, verification, and creation of these stages of development.

The merits of EtherCAT in industrial applications are well known. The global adoption of Ethercat, especially on multi-axis servo machines, has been very compelling, at least from the perspective of TI’s C2000 market. With the EtherCAT Technology Group (ETG) surpassing 4,300 members and the growing and balanced mix of global members not dominated by Europe, it is clear that the overall EtherCAT solution, technology, availability, licensing, support, etc. Industrial customers resonated.

We have seen many customers take on the task of enabling C2000 MCUs to run the EtherCAT stack natively, especially in motion control applications. Integrating real-time communications directly into the real-time control development environment simplifies the development process. Clearly, integration into a single central processing unit (CPU) would simplify synchronization between network interruptions and real-time control loop timing.

The C2000 MCU is fully capable of executing the software stack and simultaneously performing demanding real-time motor control, primarily because the EtherCAT hardware is capable of handling the most challenging real-time elements of EtherCAT communication. A single CPU has significant advantages in reducing cost and board space compared to adding a secondary CPU to run the stack. System performance also benefits from reduced transport latency if you use the extra CPU to process the stack. In motion control applications, the time or delay for the system to respond to a new target position is critical. Why minimize position control loop time if position command input timing cannot keep up with control loop function? A temporary CPU running the EtherCAT stack may affect overall motion performance.

Given the complementary aspects of EtherCAT and C2000 MCU motion control and customer support requests, TI leveraged its embedded software development experience and C2000 MCU architecture knowledge to create a software solution designed to help develop EtherCAT slave nodes for TI’s real-time control MCUs. This package requires little development investment and helps you:

Evaluate the stack of the slave node.

Verify proper operation or connection of custom hardware.

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

Figure 1: C2000 MCU native EtherCAT slave stack support flow

Figure 1 shows the three stages of developing a self-developed slave node application. It also outlines hardware assumptions and describes the software modules that can be used to support each stage. We will spend more time answering each stage of support in subsequent blog posts. However, the next blog post in this series will describe some of the specific features enabled and the steps taken to make slave stack development on C2000 MCUs more attractive for real-time control applications.

Other resources

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

DesignDRIVE training portal.

DesignDRIVE application portal.

The Links:   KCS057QV1AJ-G20   2DI50D-050A