Monitoring System For Plastic Extruders Operation

Up till now, plastic extruders operate independently. The equipment operating parameters can't be monitored real time and the historic data can't be looked up either. The quality of the products totally depends on the proficiency of operators. It brings great disadvantages to management. In order to solve the problems, a new type of plastic extruder monitoring system is proposed in this dissertation. In the system, each manager(ARM microprocessor) by means of RS-485 filed bus collects and stores operating parameters from slave computers real time and transmits to PC to form historic data report. Thus the real-time displaying of remote data and scientific management can be realized in the systemA distributed real-time monitoring system is put forward in this dissertation in which AT91SAM7S64 microprocessor,μC/OS-II operating system, RS-485 and Modbus were used as the hardware platform, software platform, field bus and communication protocol respectively. Two-lever supervision structure consisted of ARM management units and PC based remote data management centre is beneficial to managing data and programming simply. RS-485 filed bus makes it convenient to establish network. Modbus communication protocol guarantees data transmitted reliably. The advantages of ARM processor andμC/OS-II embedded operating system based to implement multitask management and communication improves reliability, expansibility and real time of the system. Consequently, the system can meet different filed applications.In this dissertation, the selection of the system scheme is firstly introduced according to the requirements of the research, and thus the whole structure of the monitoring system is designed. The design of the hardware and software of the system are then illustrated in detail. In term of the hardware design, the ARM microprocessor, the design of its peripheral circuits and the circuit analysis of the slave measurement modules are fully discussed. In the light of the software design, it includes manager and PC application program. The soft system structure of the manager is designed by use of Data Flow Diagram and the tasks which include the communication processing between slave modules and manager, data acquisition and processing and the communication processing with PC are implemented based onμC/OS-II. The PC interface design is completed based on ActiveX Control which has friendly graphic user interface and high code reuse and Control transplantation. Finally the debug method of the system and the experiment results are introduced.Many tests indicated that the designed monitoring system of the plastic extruder had excellent features and satisfied all required performance.