In today's industrial control systems, industrial fieldbuses have been used in large numbers to reduce application costs and improve system stability. After entering the Industry 4.0 era, industrial real-time Ethernet industrial bus application also gradually occupies the dominant position of industrial fieldbus, such as PROFINET bus led by Siemens, EtherCAT bus led by Pepperl+Fuchs, Ethernet/IP bus led by Rockwell, etc.. Industrial real-time Ethernet bus has gradually become the mainstream configuration of the new generation of industrial control systems, and at the same time, it has become the basis for entering the era of industrial digitization.

EtherCAT industrial real-time Ethernet bus with its high performance, high stability, high response and other characteristics of the industrial control system to be widely used in the rapid, at present the EtherCAT master in the high-end PLC products have been widely used, but in the more cost-sensitive compact PLC controller, the current domestic PLC is still Modbus, CANopen and so on, the low-speed Communication protocols, through independent research and development of the NXTOS system to achieve the domestic GD32F470 processor EtherCAT master function (the future will provide PROFINET soft slave and Ethernet/IP master-slave program), and support for the IEC61131-3 standard PLC programming as well as graphical master configuration and debugging tools, the core features of the program are as follows:

∎ Use of GD32F470 processor on-chip resources (based on GD32F470ZIT6 or GD32F470VIT6)

∎ Access to EtherCAT slave process data and object dictionaries based on the NXTedge Studio programming tool using the IEC61131-3 standard language

∎ Supports import of standard EtherCAT ESI device description files.

∎ Online scanning configuration and EtherCAT master-slave parameterization possible

∎ Online monitoring of EtherCAT slave device status and manipulation of PDO process data as well as reading and writing of object dictionaries via SDO

∎ Supports up to 9 EtherCAT slaves, typically 8 servo drives plus 1 IO module, with a stable EtherCAT limit cycle time of 250us, typically 1-2ms.

∎Provide more flexible cooperation mode, can provide software SDK in-depth research and development mode or based on the customer's hardware platform NXTOS system product authorization mode.

Our company and Joyce Innovative Company have cooperated deeply and jointly released the EtherCAT master solution based on GD32F470 single chip.

The selected GD32F470VI/GD32F470ZI chip is based on Cortex-M4 core with 240MHZ main frequency, 2MB FLASH, 768KB RAM, which can realize the IEC61131-3 PLC software platform and EtherCAT master through a single chip, and control 8 EtherCAT servos and 1 EtherCAT IO module at the same time. EtherCAT IO module, through the expansion of the Ethernet chip to support TCP / IP communication, Modbus TCP and private Ethernet communication protocol, while supporting IEC61131-3 standard programming, support for FBD, LD, ST, SFC and IL programming language, the application architecture is as follows:

Based on GD32F470 processor chip, in the scenario of connecting 8 EtherCAT servo and 1 EtherCAT IO module, it can still realize 1ms communication cycle of EtherCAT master, in which the single cycle of EtherCAT master only occupies the maximum processing time of 120us, and the processor still reserves enough CPU resources for guaranteeing the operation of other PLC application logics, Modbus communication, motion control and so on, and at the same time, it can realize the debugging of the state of EtherCAT master in NXTedge Studio:

In addition to the PLC solution supporting EtherCAT function through a single chip, the solution also supports the GD32F470 chip as an independent co-processor to communicate with the third-party processor, and the application with high real-time requirements will be completed by the GD32F470+NXTOS, whereas there is no need to optimize the real-time on the HOST processor, which communicates with the GD32F470 through the SPI/UART interface to access the industrial control system: