السبت، 15 أغسطس 2009

2.1: Introduction to our project


These days, home automation is very important. Home automation involves an integrated system of monitors that automatically operate different functions such as lighting, heating, cooling, ventilation and elevator systems, Appliances and security (Fire, Burglar…) alarm. Any company works in (control systems) technology field might get benefits from this project. Companies may setup a full office automation system to its clients. Hotels may be automated by this project to have more Lodgers.

Tourism can have huge benefits because tourists number might be increase, hence the national income will increase. This project will consume the time which be wasted in manual process inside (homes, offices, hotels…) in business [time is money]. Handy-cap and older people can have special care.


This project is useful in understanding and learning more about plc

That mean that it is an educational project that it is useful in laboratory to learn students how the plc work using actuators (output to the plc) as (fan, ventilator, valve,….etc) and using the push buttons are the input of the automated process which can be start or stop operation(security , HAVAC) and using sensors as (Temperature , smoke , photocell, photoelectric) and how use all tools of plc as timers

Our project consists of board which contain push buttons &sensors& actuators. And each process is connected below the wood that was designed to disappear the wiring connection of each one . the following steps is a systematic approach of control system design such this steps help you how to use the programmable logic control .

  • A systematic approach of control system design using a programming logic controller:

The concept of controlling a control system is very simple and easy task it involves systematic approach by following operation procedure

  1. Determine the system sequence of operation .

Firstly you have to decide what system you want to control the ultimate purpose of the programmable controller is to control an external system . this system to be controlled can be process and is often generically called the control system .The movement of the controller system is constantly monitored by the input devices that give a specified condition and send a signal to the programmable controller outputs a signal to the external output devices which actually control

the movement of the controlled specified and thus achieves the external control action .

2. Assignment of Inputs and outputs:

Secondly , all external input and output devices to be connected to the programmable controllers must be determined . the input devices are the various switches , sensors , etc . the output devices are the fans, sirens , valves, motors etc.

After identifying all the various input and output devices , assigned the numbers

corresponding to the input and output number of the particular programmable

controller you will using . the actual wiring will follow the numbers of the

programmable controller . the assignment of INPUT and OUTPUT numbers be

carried out before writing the ladder diagram because the number dictate what is the

precise meaning of the contacts in the ladder diagram .

3. writing of the program :

Next , write the ladder diagram program by following the control system sequence of operation as determined by step one.

4.programming into Memory :

Now , you can apply the programmable controller . depending on the type of programmable controller , you may have to do a I/O generation to prepare the system configuration . After that , you program in the memory by computer aided ladder software

tool. After completion of the programming , you should check for any coding errors by means of diagnostic function , and if possible simulate the whole operation to see that it is alright .

5. Running the system:

Before the start push –button is pressed , thorough ensure that

the input and output wiring are correctly connected according to

the I/O Assignment. Once confirmed, the actual operation of the

plc can now be started . you may need to debug alone the way

Test run thoroughly until it is safe to operate by anyone.

After we speak about how to design a control system using programmable logic control (PLC) we will describe our project Briefly . then speak about each one inputs and outputs in details in the next chapters .



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