Implementation of Door Control System Using Ladder Language

With ever-growing increase in computing power and personal computer popularity, the processors are becoming relatively inexpensive. This has led to a surge in the affordability of Programmable Logic Controllers- the brain behind many machines. In this paper mainly focuses on programmable logic controller used for automatic door control system which will be open during entrance and during exit. In this paper we also focus on counting the number of people enters or leaves in industries or conference hall. Here the total number of people present will be display on the screen. PLC was designed to replace relay logic systems. Automated industrial production line in the sixties and seventies consisted of huge electrical system controls and frequently it covered an entire wall. Within this board there were a great number of relays to make the whole system work. The plan given to electrician, for making connections, was called Ladder schematic. In this paper PLC programmed in ladder language which strongly resembles with relay logic. PLC ladder logic allows the programmer (the person writing the logic) to see any issues with the timing of the logic sequence more easily than other formats. PLC interface some input and output with a hardware device and it operate with the help of programmer. Here an Allen Bradley (AB) PLC is used to control the virtual model of a door control module. Door Control System is important from security point of view as well as for disabled persons also.