The Application Of Ethernet Communication Technology In Chromatography System

Chromatography system is an important component of packing printing machine, which is responsible for controlling the accurate localization of each color. It plays a decisive role to printing quality.The paper first introduces the development of Ethernet briefly, and compares Ethernet with other field buses. This paper also gives the reason using Ethernet in the Chromatography system. This paper also introduces TCP/IP protocol structure. Considering resource of the local micro controller is limited, transport layers of TCP/IP protocol stack use UDP protocol which is unreliable. Among this paper UDP, IP and ICMP are in key introduction, also introduces the datagram of these protocol and the function of these protocol.After finishing introducing the realization environment of the Chromatography system, this paper introduces the operation principle of the Chromatography system especially. This system adopts intaglio printing. The user interface is in the center of the system, monitoring the whole operation of the system. In the control unit, local micro controller controls color register procedure and transmits data to user interface; Photoelectric detector and photoelectric encoder carry on the deviation to measure.The user interface designed by Lab VIEW 7 Express, produced by NI Company. Lab VIEW 7 Express is a kind of graphical programming language and it is used the widest at present. The main program is divided into two parts of control procedure and communication procedure. The control procedure is responsible for setting parameters and data processing; the communication procedure is responsible for data transmission. The control procedure is divided into 3 modules: parameters setting module, monitoring module, data processing and displaying module . The parameters setting module is responsible for setting up parameters; The user interface send the encapsulated date to local micro controllers by Ethernet; It is after the data transmission is finished that the monitoring module start running. The data processing and displaying module display the system running result in form of wave graph, after received the data form local micro controllers. In the description of main program, the paper gives lots of flow charts and procedure block diagrams.End in paper, according to the running result, this paper provide analysis on system debug, and give discussion on the system debugging.