Profibus-dp-based Data, Research And Design Of The Unit

Fieldbus is one of focus in automation, it is called LAN of automation. Among the present fieldbus standards, PROFIBUS is the popular fieldbus. PROIBUS-DP that used in distributed equipment for high speed is a high market share fieldbus technology."The development of automation system for raw natural rubber" aims at promoting efficiency and reducing energy in making rude rubber. The project is more advanced and innovative than traditional method in making rude rubber. The project ceters on PLC and is implemented step by step. Controller is PLC of CPU 314 with PROFIBUS-DP interface. Through researching on PROFIBUS fieldbus protocol, developing equipment with PROFIBUS interface and connecting to PROFIBUS, all above has great significance in promoting technology and characterizing. It also has realistic significance in promoting application of PROFIBUS in our country.Basing on ISO/OSI reference model and project of "The development of automation system for raw natural rubber", the paper takes the example of display module and design PROFIBUS-DP intelligent slave. After introducing physical layer and data link layer of PROFIBUS-DP, analyzing communication process between master and slave, researching frame structure and GSD file etc that is the key content of PROFIBUS-DP, the solution of singlechip computer and ASIC is used to realize the intelligent slave. Intelligent slave that is for displaying parameter is constituted by protocol chip SPC3. The hardware of the module refers to IM183 module of Siemens. MCU is AT89S52 singlechip computer. With extended function modules, the hardare is integrated in the same circuit board. The software adds function of data process and display based on DPS2, which is the firmware of SPC3.Through using PLC of 314 as master, using display module as slave, with the method of monitoring message in PC, the experiment successly validate the communication between display module and equipment of Siemens. The prospective target is achieved. The method paper present can be applied in control, acquisition system for displaying parameter (for example, temperature, pressure, speed, voltage, circuit, power, time, fault code).