Application Of PLC To DCS For Broadcast & TV Equipments

On the basis of studying the current situation in the computerized monitor and control research field for broadcasting equipments, this paper studies the DCS, PLC and LAN, designing a distributed automatically monitoring and controlling system based on PLC and LAN. After thinking about the reality of the equipments of broadcast & TV equipments and the functional requirements of the computerized monitoring and controlling system for broadcasting equipments, we introduce the overall scheme of design and draw out systematic structural representation in the thesis.The computer-monitoring and controlling system for broadcast and TV equipments is composed of Local LAN, Control LAN and long distance management LAN, which can be separated into the following several portions according to the structure: data acquisition subsystem, host computer subsystem, duty monitoring and controlling subsystem, report forms printing subsystem, database server subsystem, system time proofing subsystem, and so on. The main functions of this system are as follows: telemetry system, remote signaling and remote controlling the equipment, automatically switching on and off the equipment, automatically creating report forms, giving an alarm automatically when there' s something wrong with the equipments.The emphasis of this paper is studying application of PLC to DCS for broadcast & TV equipments. Primary content is that the design of the on-site monitoring system base on PLC. It introduces the design of the PLC program and the data collection subsystem and the circuit for the PLC output control in detail. In the design process, according to the control request of broadcast and television transmitter, combining the structuring programming designing method, the PLC program is divided into 9 parts, and carrying on the design to each mold piece.In addition , in order to assure the system dependably runs in the environment of the strong electromagnetic interference , this paper puts up lucubrating on the design of the electromagnetic compatibility , the grounding , and the power supply for the PLC control system.