After going through tedious working days isn’t it a wonderful thing if people can just relax on the sofa and control the temperature in the living room, just with single button the room temperature can be controlled automatically so when the room temperature is too cold the heater will operate to produce a regulated temperature and when the room temperature is too high the cooling system will operate to produce the desired temperature.
There are four objectives to be achieved in this project. Below are the following objectives: 1.2.1 To design appropriate circuit for temperature control. 1.2.2 To design software using plc for temperature control.
1.2.3 To interface plc module with the input and output components. 1.2.4 To design a prototype system for temperature control.
1.3 Scope of the Project:
To achieve the objectives and purpose of the project , the scope of study and research can be divided into following areas: 1.3.1 Design and develop the prototype of the temperature control system by using plc as the controller to enhance the existing system. * This project will develop the prototype which is respect to the actual system. 1.3.2 The development of hardware and software.
1) Literature study of the hardware including PLC and others components. 2) PLC will used as the brain of the project.
3) Thermostat sensor will be used as the sensor for temperature. 4) DC power supply.
5) Fan will replace or represent the air conditioning system. 6) Hair dryer will replace or represent the heater system.
1) Several literature review of the CX-Programmer for the PLC Allen Bradley 2) Ladder diagram as the source code to the PLC.
1.4 Problem Statement:
Temperature controller is really important to monitor and adjust temperature without much operator involved. Without proper temperature control facility the system could be adversely affected and the end results may not be what we desired. So the presence of an optimum temperature control system is of paramount importance. Basic process involves the measuring of temperature of the room/house whose temperature you are attempting to control and also to maintain that target temperature. Earlier there were control panels used for this process but they had disadvantages associated with them such as:
Disadvantage of Conventional Control Panel:
There were too many wiring networks in the panel.
Modification could be quite difficult.
Troubleshooting could be quite troublesome as skilled persons were required.
Power consumption was quite high as the coils consumed power.
Machine downtime was usually long when problems occured, as it took a longer time to troubleshoot the control panel.
Drawings were not updated over the years due to changes. It took longer downtime in maintenance and modification.
There are various types of controller in the market such as ON/Off, proportional and PID. In this project, PLC has been chosen as the controller. The advantages by using PLC are the number of components for example relays and timers, the wiring and additional hardware for each new configuration of logic can be reduced and easy to troubleshoot when the error has occurred. 1.5 What Is PLC:
A Programmable controller is a solid state user programmable control system with functions to control logic, sequencing, timing, arithmetic data manipulation and counting capabilities. It can be viewed as an industrial computer that has a central processor unit, memory, input output interface and a programming device. The central processing unit provides the intelligence of the controller. It accepts data, status information from various sensing devices like limit switches, proximity switches, executes the user control program store in the memory and gives appropriate output commands to devices like solenoid...
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