After years of development, the most common bus servo technologies in China are the CAN bus and bus servo. Common bus chips are typically 485 and CAN communication chips. In reality, these high- and low-voltage bus transmission modes are unstable and unsuitable for industrial products. Furthermore, this communication bus has been popular in the Chinese market for decades. As a pioneering technology with a low barrier to entry, it is widely used in various industrial control devices, such as PLCs, motion control systems, and remote I/O. Many engineers are familiar with these two bus technologies. However, due to limitations in hardware performance and software protocols, the CAN bus is primarily used in applications with small data volumes and low real-time requirements. Its capabilities are somewhat limited for applications with large amounts of data and low latency.
With the advent of the Industry 4.0 information age, industrial field applications are increasingly demanding high-volume data communication and real-time performance. To address this, high-speed industrial Ethernet buses have emerged. Ethernet-based hardware performance and improved data exchange protocols can meet the needs of most high-speed, large-data, and real-time scenarios. Among various industrial Ethernet buses, bus servo is particularly popular in China. The popularity of bus servos is primarily due to the following reasons:
1. The EtherCAT protocol is a completely open protocol. Any company can use it and become a member.
2. The master uses a standard physical layer and data link layer, requiring no additions or modifications to existing hardware.
This protocol simply improves the data flow model within the Ethernet protocol; it is a purely software-based change.
3. Many chip manufacturers have directly integrated EtherCAT slave implementations, making EtherCAT slaves very easy to implement.
However, bus servos are not as popular as CAN bus because the implementation cost and technical barriers to entry of the EtherCAT master are relatively high. Key non-utility data includes basic control board parameters, function settings, diagnostic functions, servo motor status, and alarms. The transmission rate is relatively low. The CAN socket power adapter acts as a bridge between the host computer software and the servo motor module, transmitting data and controlling the servo motor. The servo motor module collects data and information on-site and transmits it to the host computer software via the system bus for real-time monitoring. Since its founding, our company has focused on the research and development of specialized motion control systems, evolving from injection molding and extraction robot control systems to current robotics control systems. In terms of control execution, we have evolved step by step from pulse, CAN bus, RTEX bus, and finally bus servo, accumulating extensive experience in industrial motion control. In 2015, China vigorously promoted Industry 4.0. We responded positively and began developing integrated drive control systems and bus servo servo systems. As we developed our own bus servo servo system, we discovered that the EtherCAT master solutions currently available either used Beckhoff's Twincat software or licensed software from foreign companies, often at very high prices. As a key technology for Industry 4.0, it remained under the control of others. We could not accept this fact. From that moment on, we decided to develop an EtherCAT master specifically tailored to our motion control system.