Monthly Archives: June 2012

Arduino as a PLC

Siemens S7-300


God made the cat in order that man might have the pleasure of caressing the lion.  ~Fernand Mery

If you know how a PLC works, if you are coming from the world of PLCs, probably you’ll find it an obvious assertion: Arduino can be seen and used ALSO as a cheap PLC substitute.

But I am almost sure there is a lot of people, in the kingdom of PCs, thinking PLCs are strange obscure devices, very hard to deal with. For those, I just say that if you look at a PLC, you see a box with usually 2 boxes (same size, by the way) beside: inputs and outputs. PLCs read inputs, process them and send commands to outputs. Do that recall something to you?

As you can imagine, PLC are industrial quality standard devices, even though somewhere you can find some Arduino versions quite… hard.

This simple fact is so true, that it’s even possible to program Arduino with ladder! For non-PLC readers, Ladder is one of the most “ancient” programming language for PLCs, dating to old times of wires and relays. I am not suggesting to you to use Ladder as the new programming language for Arduino, but I found that quite interesting.

Anyway, for those who like having some little hint about the usual way of coding Arduino, I have added this and this posts.