Research And Implementation Of WIA-PA Protocol Stack Based On CY2420

Industrial wireless technology is an emerging short range wireless technology for industrial automation and process automation. It becomes a new technical focus in industrial control field. As a national standard for industrial wireless control field, WIA-PA(Wireless Networks for Industrial Automation- Process Automation) has been voted to be an IEC international standard. WIA-PA puts forward solutions for determined reliable real-time data transmission and environmental interference in industrial wireless networks. However, these solutions need to be carried on full- featured WIA-PA stack software as support. Meanwhile, C hongqing University of Posts and Telecommunications developed an industrial wireless chip CY2420 with Uniband Electronic Corporation for the spread and application of WIA-PA standards. This CY2420 chip possesses time synchronization mechanism, scheduled communication mechanism and multi-channel frequency hopping technology. However, to make good use of these features, this chip needs to be supported by cooresponding stack software. Therefore, it is necessary to study WIA-PA standards and CY2420 fretures, and implement the CY2420 based WIA-PA protocol stack.The research aim of this thesis is to design and develop the CY2420 based WIA-PA protocol stack, and based on this, a CY2420 based link scheduling scheme and a channel selection method for WIA-PA networks are studied. The main contents of this thesis are as follows:1. The link scheduling method and channel hopping mechanism of WIA-PA standard are analysed in this thesis, and the key features of CY2420 are also studied.2. An overall design and layered implementation are proposed in this thesis, and a hardware and software co-scheduling method based on CY2420 are mainly presented. In the method, we build a schedule table function model, a schedule queue model, and the cooresponding driving mechanism, and then the major functions are implemented in the stack software.3. The channel interference in industrial environment is analysed in this thesis and an improved channel switch method for WIA-PA equipments are proposed. In the method, WIA-PA nodes evaluate the channel qualitity by the history condition of the channel, and then actively skip the bad links to avoid channel interference. The method is implemented in the stack software.4. A test system is built to verify the functions of the proposed WIA-PA protocol stack based on CY2420, and the test results are analyzed in detail.The test results show that proposed WIA-PA protocol stack based on CY2420 makes good use of its key features. It can effectively improve the stability of WIA-PA networks and the immunity from interference in industrial environments. The research results can be used as a reference for promoting the practical applications of WIA-PA networks.