Design And Implementation Of A Intelligent Gateway Based On POWERLINK Industrial Real-time Ethernet With Multiple Interfaces

Industrial field bus have developed for a long time, which mainly accomplishes the digital serial multi-point data communication among the automations. The typical models of it are rs-485 field bus, rs-232 field bus and the Controller Area Network. With the industrial automation evolution for the higher speed, the higher accuracy and the distributed control, people will be satisfied with the one who can contain the more data and transport with the higher speed instead of the traditional bus system Unlike regular replacement of equipment in the field of consumer, the field of industry have to consider the stability and costs, so currently there are several industrial control field bus standards in the domestic market. It is difficult for these different kinds of networks to communication. There could be several buses in the industrial site because of the expanding of the production scale. The multiple protocol stacks converters, for example the CAN to RS485 protocol converter, are needed for the interconnection among the different buses.Because of it low power consumption, easy installation and moderate transmission speed, etc., the short-range wireless communications will be more widely used in the industrial field. At present, industry applies the Zigbee,Wi-Fi and 433 MHz band communications.With the characteristics of low cost, high communication rates and the global popularity, Ethernet has become the next practice development direction of the industry bus. In order to overcome the shortages of the non-real-time behavior of the traditional Ethernet communication, there has been various improvement programs. The Ethernet POWERLINK abandon the classic CSMA / CD protocol, based on the standard Ethernet MAC layer and the hardware layer and innovatively use CANopen as an application layer protocol, which provides a great convenience for the data communication and network management of the Ethernet POWERLINK. It also provide a unified interface for the different devices and the particular applications.This paper introduces the concept and development overview of the industrial real-time Ethernet and exposits the principle of POWERLINK in detail.Based on the situation of the multi-protocol co-existence of the industrial field and the tends of industrial buses to Ethernet, design the overall shceme of intelligent multi- port gateway.The system consists of POWERLINK communication unit and other communication interfaces,the POWERLINK communication unit uses FPGA implementation and the other communication interfaces uses AM3358 implementation.AM3358 run POWERLINK main node user-layer code and the software contral code of other communication interfaces;FPGA run POWERLINK main node kernel-layer code. Simple but efficient data buffer and forward delivery mechanism between different interfaces guarantee the secure data conveyance.Based on the Cortex-A8+FPGA hardware architecture,the system realized the POWERLINK main node, and integrated the wired and wireless communications ways which are commonly used in the industry to achieve the interconnection between the various means of communication. The gateway function will complete by sending the site data and status to the remote server or by receiving and transmitting the command of server through the Ethernet or GPRS module.