Hello friends, in this post I am going to start sharing a information related to a new topic Programmable Logic Controller which plays a very important role in automation of every industry.

Evolution of PLC ?

Manufacturing process require a sequence of operations in order to make a product.

And in this case sequencing can be done by manually or some type of controller.

In late 1960’s sequencing operations are performed by using a bank of relays wired to perform a particular job.

But there were drawbacks, logic systems were difficult to reprogram for production changes and also troubleshooting is very difficult.

To avoid the above drawbacks PLC’s are used.

PLC’s use the sum relay logic function and sequence is not hardwired but can be programmed and stored in a memory.

The contents of the memory are easily changed.

PLC’s are used first by automobile industries.