Programmable Logic Controllers are MicroControllers ?


Joined Feb 24, 2006
That is the way they are implemented. What distinguishes them is the firmware which creates the ladder logic programming pardigm.

Thread Starter


Joined Oct 17, 2006
You Programmable Logic Controllers and MicroControllers differ ? A textbook in one differs a lot from a textbook in the other ?


Joined Oct 21, 2007
they are different but in many cases can be used to do the same thing. basically a logic device has a bunch of logic gates packed into groups and are programmed by how they get connected to each other. a microcontroller has a processor and while having some internal logic devices (counters etc) most of the work is done by the processor in software. adding subtracting comparing etc. hope that helps.


Joined May 19, 2004
if you view the definition of a microcontroller as a (generally small) system with a processor unit, memory (ram and/or rom) and limited input/output capability and with limited instruction count, yes a plc is a microcontroller.

a pla is a programmable device where the desired logic circuits can be burned into the blank component - when done can emulate a combinational logic circuit which may have taken hundreds of gates to perform.


Joined Feb 24, 2006
I don't think it matters which one you learn first as long as you're not working against a fixed schedule. If you are going at your own pace then pick one and quit wasting your time worrying about it.


Joined Oct 24, 2007
What you learn first depends on what you want to do with electronics?

If it is hobby driven then what area do you want to tinker with?

You can start in what area give you the most interest and enjoyment. Eventually though you may have to cover the basics. Check out the "All about Circuits" E-Books, see the links located at the bottom of this forum.

If it is career based, continue on your own path of interest but also consider formal education. Again what formal education depends on what path you want to take?

On this forum there are electricians, technicians, engineers, application developers embedded programmers etc.

The field is huge. Only you can determine what path you want to take.

Just my 2 cents.




Joined Jan 23, 2006
I don't know your background in electronics.

Before studying Programmable Logic Controllers, Programmable Logic Arrays or Microcontroller hardware, you should know basic electronics.

If you understand digital logic (AND gates, OR gates, flip flops, etc.) then the Programmable Logic Arrays will not be too difficult to understand.


Joined Sep 25, 2007
Like everybody else said - depends on your current knowledge about electronics. The basics are essential.

But having said that, rest assured you can work safely on PLC's even with limited exposure to electronics or engineering in general.

PLC's are all about ladder programming on a GUI. This kind of programming is made easier by the concept of dragging and dropping different building blocks, as opposed to microcontroller and PLA programming where you have to deal with a proper programming syntax.

PLC's were infact developed to assist technicians who had limited knowledge of programming syntax. With PLC's they could easily have a 'virtual microcontroller' that could control applications, with the added advantage of simple programming.

PLC's would be good for a start for you.


Joined Dec 19, 2007
My understanding is a Microcontroller is microprocessor based hardware that runs software and some basic OS. a PLD is software-configured hardware but nothing "runs" for it to maintain that configuration once it is set. is a PLD and PLA the same thing?


Joined Oct 22, 2007
the programmable logic controller(PLC)
based on the microcontroller ,the PLC have cpu which control the process
PLC is more trust in the industrial plants
so the M.C is the base of the PLC


Joined Dec 23, 2006
If you're going to work in a very industrial atmosphere such as assembly lines at factories, then you typically will only deal with PLCs. At my college there are a lot of folks that take the class for that specific purpose. PLCs and Microcontrollers are essentially the same, it's just that PLCs follow a specific standard including ladder logic and hardware designed specifically for higher voltages.