Design Of Distibuted Control Systerm Communication Master Based On Profibus-DP

Distributed control systems(DCS) is one of the best control platform, because of its high reliability, high flexible configuration, easy maintenance. However, the dedicated controller and bus interface make the lack of interoperability between products from different manufacturers. It also reduces the openness of the DCS system and is not conducive to system expansion. At the same time,with the development of integrated circuits, intelligent sensors, actuators, drives are increasing gradually, traditional 24 V and 4-20 m A parallel signal lines have been unable to meet the requirements of the serial digital communication between intelligent devices. Therefore, the introduction of the open digital communication bus standard, which do not rely on equipment manufacturers, becomes extremely important and urgent to the DCS system.Process Fieldbus is one of fieldbus standards which meet the requirements. It is widely used in manufacturing automation, process automation and building industry, transportation, electricity automation and so on. Profibus-DP is the important part of Process Fieldbus, it can be used to replace the expensive 24 V and 4-20 m A parallel signal lines. Profibus-DP communication master is the core module of communication systerm, the main functions are data exchange, system configuration, troubleshooting and so on.The dissertation introduces a design of Profibus-DP communication master. In terms of hardware, general-purpose digital signal processor and peripheral memory, transceiver are used to the real time process of communication data receive and send communication data. In terms of software, core state machines and auxiliary functions are used to analysis Profibus-DP protocol and achieve data downloading, periodic communication and non-periodic communication functions. Experiment show that the design can achieve communication master function reliably, can be used to replace expensive dedicated communication master chip. This design has a high research value and practical significance.