C /C++ in PLC or in Automation


Thread Starter


Hi to all automation engineers..

Anyboday can help me what is C/C++ in PLC?
i know how to program PLC using laptop, i know how to configure the data. Wiring installation.
i'm using ladder method. Our PLC is Melsec and we used GX-Developer software and Omron we used CX-programmer.

My question is sometimes there's a hiring need [for a] technician or engineer in PLC [requiring] C++. how it means?

C++ is the same of statement list like ( OR , LOAD , ORB , ANDB and etc.. ) ( then , if , go and etc.. ) programming.

My last question: [Is] the Melsec GX-developer software available to program in C++?

Michael Griffin

If I had to guess without seeing the actual item you are referring to, I would guess that the requirement is for someone to do mainly PLC programming, but must also be able to do C and C++ programming for PC projects.
Maybe it's because not all PLCs uses LADDER (LAD) Logic or Function Block Diagram (FBD). In some cases, Statement List (STL) programming is used. In this case, a background in computer programming (maybe C or C++) is a must. Siemens PLCs do support this kind of programming, and I guess other PLCs support this too. Since most PLC programmers are not that adept in computer programming, this is rarely used in the industry...
Anyway, programming languages like C, C++, and Visual Basic are also used (mostly) on HMI development. They are used in scripting of various HMI softwares. It is a big plus if you know how to program a PLC and at the same time, program an HMI.

Jarmo Aaltonen


I am an electronic automation specialist from Finland. What I have noticed is that user interfaces in automation cells are quite often created by VB or C++. So if you work with independent automation cells it is a big advantage if you handle both tools, PLC and, for example, C++. You reach a bigger number of customers, and if you have a company of your own you can charge a better hourly price.