Research Of Communication Technology About Laboratory Monitoring Control System Based On CAN Bus

With the development of industry towards automation and modernization, in theindustrial production process, production equipment often needs automatedinspection,intellectualized control and network management to raise the enterpriseproduction efficiency and realize unmanned production process. At the same time,in the remote control realizable way, internet network has begun playing anincreasingly important role, combining field bus with the network remote control,network technology has become one kind of important realizable plan of controlsystem, using the field bus to complete the concrete control function, realizing controlnetwork and information network’s integration through the field bus internet accesstechnology, the enterprise may realize the remote monitoring function via internet.Based on this, a remote control system has been set up which is based on the twomodes of C/S and B/S through using LABVIEW.In the long-distance control laboratory system, users log in the system through abrowser, they not only can operate the remote laboratory equipment and gainexperimental data but also be able to observe the real experiment process throughoperation long-distance network cameras. Many means of communication can beeasily used to transfer data to a remote browsing, but a program must be written toaccept the data on the remote computer.In many cases, users want to move directlythe local panel to a remote computer to view and operate, the web service technologywhich LABVIEW provides can intact panel presentation on the remote computer.This mode of operation can not only directly operate a remote network, observe theexperiment process and obtain experimental data on the server computer.if theremote users know the server computer’s IP address or the network address whichthe long-distance experiment issued. They may also observe indirectly experimentprocess or gain experimental data through network on the client computer. Therefore,the laboratory remote control can be easily realized through the network. This article mainly discusses the remote control system based on CAN card.LABVIEW is used as programming tools. The system carries out remote control onthe client computers which are installed LABVIEW through the agreement of TCP/IP,similarly it transfers DLL file of driver ZLG CAN PCI-5110through LABVIEWserver and user interface program of remote control system, realizing the operationclient with the remote terminal CAN lower computer node equipmentCommunications to achieve the purpose of remote online monitoring and control.The hardware network which this remote control system uses is: the clientcomputer is connected with the server on internet somewhere through the agreementof TCP/IP, and the master cards of ZLG CAN PCI-5110are inserted on the PLCslot of the server motherboard. Card CAN is connected with the Siemens S7-200CPU226PLC by the twisted pair line diameter CAN transferring485protocolconverter to realize the control of lower positions node terminal device. This papertakes LABVIEW computer program controlling lift experimental platform of SiemensPLC S7-200as the example. Introducing in detail the calls of the dynamic link libraryof CAN driver, as well as a detailed analysis of Function of various parameters of thedriving dynamic link library.