Research On LON Node Using Dual Processors Based On Neuron Chip And Microcontroller

LonWorks technology that was developed by American Echelon Company in 90s is a kind of completely open fieldbus. As a single processor, Neuron chip cann't accomplish high real-time, multi-process, multi-tasks parallel processing, and cann't meet needs of field devices requiring majority in acquisition and control, so development and design of LON node based on MC143150 and AT89S51 is discussed, aiming to reducing external event processing in the Neuron chip and fully developing own superiority on communication and meeting real-time monitoring requirements of system by quick information exchange between AT89S51 and field devices.Theory of node development technology is discussed on level dividing, mainly including Neuron chip and LonTaLk protocol of Lonworks technology, the hardware and software of microcontroller. On this basis, the thesis emphasises on hardware and software development process of digital input/output node and analog input/output node including power module, input and output channel, memory extended interface, communication interface, interface between MC143150 and AT89S51, clock circuit, reset circuit, crystal circuit etc, also including programming for MC143150 and AT89S51. In order to make node have optimal performance, stable power supply circuit is designed using MAX1677 and MAX8876; 32kB extended storage circuit is designed using AT29C512; Input and output channel is designed using photoelectric isolator; MAX197 and MAX527 being able to exchange information accurately and rapidly have high anti-interference ability. Communication interface is designed using FTT-10A transceiver being able to meet high performance and high common-mode isolating requirements of system.In order to make node have characteristic of compact size, high perfor- mance/cost ratio, high reliable and reducing taking up of resources of the hardware greatly, adapting to the demands of integration and miniaturization, the interface between MC143150 and AT89S51 is designed using a new kind of SPI and I2C serial bus, which occupy less ports, save space for layout of PCB. Programming for data exchange between MC143150 on which Neurowire and I2C object is declared using Neuron C language and AT89S51 on which SPI and I2C serial bus interface are declared using C51 language. At last optimized measures for properties of node are introduced in detail.The experiment shows that LON node based on MC143150 and AT89S51 overcomes negative effect of scheduling mechanism of event inspection, so it can control complex system.