Implementation of online temperature controller based on LabVIEW

Abstract

LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench) is the software which gives virtual existence of hardware, reduces its cost and hence termed as Virtual Instrumentation. This thesis presents the implementation of ON/OFF and PID controller for controlling the temperature of a heating element inside a wooden box with the help of LabVIEW. In this software, DataSocket Protocol and Transmission Control Protocol (TCP) are used for developing an online transmission process between client and server. Client has control over the set point and Server has control over the temperature. With the help of internet protocol, client provides the value of set point according to which the control actions are taken by the server. The paper also includes discussions regarding the advantages and disadvantages of TCP/IP. Written communication in LabVIEW refers to communication via internet where the user can write messages to another user. Generally written communication is not found in any programming related software but LabVIEW makes this possible using internet protocol. This helps in easy and fast transmission of data in form of messages between the client and server PC(s). After the transmission process gets over, the transmitted data is used for implementing PID controller. The various responses in PID controller are obtained by varying the tuning parameters. The responses are with respect to three conditions in the controller. On studying the response curves, parameters like setting time, rise time and maximum overshoot are obtained. A comparison table is obtained for these parameters and helps in deciding to choose the values for tuning parameters of the controller.