Research And Implementation Of POWERLINK Based On The VxWorks Operating System

In recent ten years, as the rapid development of the Internet technology, the Ethernet has became the dominant network technology in commercial communications. The transfer rate of the Ethernet is much higher than any other profibuses at present. The Ethernet with 100Mbps even up to 1Gbps has been widely used, while the highest rate of the traditional profibus is only 12Mbps. People expect that the Ethernet can also be applied to industrial control field, and replaces the existing various bus system gradually with its lower cost, higher communication rate and global universal standards.But as to the industrial control field, the real-time is more important than the transfer rate. In order to solve the real-time problems of standard Ethernet in the process of the communication, many manufacturers have introduced their own solutions. At present, there are many types of real-time industrial Ethernet, which can be roughly divided into four categories: the method of combining the Ethernet and TCP/IP; the method of modifying Ethernet MAC layer directly; the method of attaching real-time scheduling layer to the data link layer; the method of the bypass channels based on the optimization, and the method based on the synchronous clock protocol.This paper chooses the Ethernet POWERLINK as the object of study after comparing to other existing real-time solutions, which has the properties of good openness, high reliability and low cost. Starting from the analysis of its working principle, this paper studies the openPOWERLINK protocol stack, thus the principle and the interface of the VxWorks network protocol stack; and modifies the clock driver module of the openPOWERLINK based on the PowerPC hardware; then bounds the openPOWERLINK to the VxWorks operating system through the MUX interface to complete the transplantation of the real-time Ethernet protocol stack. Finally, this paper tests the actual function and performance of the openPOWERLINK based on the PowerPC hardware, focusing on the test of the minimal communication cycle, the maximum data payload, the communication of the multiple managing node, and the switch time of a standby managing node to a active managing node.