Design And Development Of Controller Based On The Ethernet

With the development of information network technology, the application of Ethernet technology in the instrumentation and industrial equipment field is a trend for the industrial control networks. The industrial Ethernet control system consists of field control level, the upper-level monitoring level and remote monitoring level. The Ethernet-based controller forms a connecting link between the preceding and the following in the network monitoring which works in the field control level. It is located on the spot where the sensors and actuators are placed. It can complete the live data collection, storage and processing independently. On the other hand it can upload the collected data to the interactive interface on the server via Ethernet in order to display and analysis the real-time data. At the same time it can also receive the server’s command and control the devices in the field in time. The application of the Ethernet-based controller is very broad, so this study has a very large practical value.The design and development on the Ethernet-based controller mainly included two aspects, hardware design and software design. In the part of hardware design, the controller selected C8051F120 chip as the core part and CP2200 as the Ethernet interface chip which was launched by the cygnal company in America. The peripheral equipment included power supply module, control module, reset module, JTAG debug module, circuit protection module, driver module, Ethernet communication module and serial communication module. The software design included microcontroller design and interface design of the PC monitoring and configuration. Silicon Integrated Development Environment (IDE) uses C or assembly language to develop microcontroller. It consisted of hardware and software simulation, debugging and downloading programming. It is software which is designed for C8051F chip specifically. So the preparation of the microcontroller C8051F120 procedures is in the Silicon Laboratories IDE. The program of Microcontroller software design included the integration of the TCP/IP protocol and the implementation of each functional module. Visual Basic is a visual, object-oriented, event-driven and high-level structured programming language. It can be used to develop various applications in Windows environment. So the design of PC monitoring and configuration interface uses VB to develop. VB interface program should be corresponded with the SCM process. The controller can realize the following functions: capture analog input and digital input; output pulse and the duty cycle is adjustable; output frequency triangle wave, sine wave or square wave; modify and query the IP or port number online or via the serial port; adopt positional PID, incremental PID or fuzzy control method to control the controlled object and so on. After the realization of software and hardware design, The temperature of dual-chamber electric furnace was used as the controlled object. The designed controller was used to control the temperature, observer the control effect and verify whether the controller was working properly. The experimental results showed that the controller was operating normally, transmitting data stability in time. So the controller achieved the design goals.The controller’s parameters can be configured. The control methods are available. It is a universal controller. It can be applied to different construction spot and different controlled object. It also has a good interface. With the Ethernet communication interface, RS23, RS485 communication interface, the multiplexer inputs and outputs, on the whole, the controller meet the requirements of industrial control.