STEP7 Based Modular Program Design Of Central Air Conditioning Control System

Centralized air-conditioning system has been widely used as one of the traditional industrial HVAC products.Now commonly equipped with PLC which is used in industrial control system,centralized air conditioning system becomes more reliable and easier for programming.It performs auto monitoring function by inputting from host computer with preset program,controls valve,pump,temperature and humidity sensors,provides real-time,dynamic screen display in configuration pictures and results outputs to guest computer.Recently,the programming and operation of centralized air conditioning system is according to user's or industry's requirements,which usually do not have standardized or modularized template,may cause time wasting and mistakes as well as difficult to set the modify program configuration,also difficult to set the process parameters.To analyze the user's designing method of centralized air conditioning system,clear the control system design STEP7,development and function of SIEMENS PLC software,the design and development of regulator unit that controls and operates temperature sensor,valve,fan and other components with DI\DO\AI\AO modules in a distributed development way specializing in program structure optimization and human-machine interface practicality.Also we analyze the system which uses the SIEMENS PLC which executes field information collection,data calculation and actuator input/output control.The SIEMENS WINCC which performs communication and real-time monitoring of central air conditioning data.Through the modular design of the complete air conditioning control system,control functions of modeling and simulation,the combination of these two components can help operator with more convenience in use and enable the stability of system and temperature control as well as meet the operator's requirements for the program reading and modification.Make sure that the stable operation of the central air conditioning control system,ensure the stability line temperature control.