Qt for plc

markolino · wrote on 26 Apr 2017, 21:23

Qt for plc communication

Hi i'm Mark and i'm writing from italy.
Usually i use visual studio to create desktop application that communicate with plc siemens, read and write data to them and set event in my gui by data from plc.
But i ma fascinated from qt. I've need to know if with qt and c++ is possibile to do the same, ora is better to use wpf.

SGaist · 27 Apr 2017, 15:59

Hi and welcome to devnet,

How are you communicating currently with your PLC ?

markolino · S SGaist 26 Apr 2017, 22:10

@SGaist
Hi thanks for the answer. Usually I communicate with my plc with a Windows form app using s7.net librery. All by profinet connection

VRonin · wrote on 27 Apr 2017, 16:28

S7 offers a C API (https://cache.industry.siemens.com/dl/files/203/13649203/att_38732/v1/mn_s7api_e.pdf) you can use that to communicate with the PLC

kahlenberg · 12 Oct 2018, 02:26

Hi,
I am exactly doing what you wanto to do. Qt doesn't have any possibility for the communication to PLC, by nature. However I communicate with PLC using SNAP7 library. This library is only for Siemens S7 PLCs, and it is really great and you can find pre-compilerd binaries as well, if you don't want to compile yourself. I downloaded and compiled source code and am using this library for reading and writing variables in PLC. You can easily integrate it in your Qt application.
SNAP7 source: http://snap7.sourceforge.net/

Zelas91 · wrote on 12 Oct 2018, 02:26

This post is deleted!

Zelas91 · wrote on 12 Oct 2018, 03:26

@kahlenberg said in Qt for plc:

Hi,
I am exactly doing what you wanto to do. Qt doesn't have any possibility for the communication to PLC, by nature. However I communicate with PLC using SNAP7 library. This library is only for Siemens S7 PLCs, and it is really great and you can find pre-compilerd binaries as well, if you don't want to compile yourself. I downloaded and compiled source code and am using this library for reading and writing variables in PLC. You can easily integrate it in your Qt application.
SNAP7 source: http://snap7.sourceforge.net/

How did you do it for qtcreator?

VRonin · 12 Oct 2018, 07:33

http://doc.qt.io/qtcreator/creator-project-qmake-libraries.html
http://doc.qt.io/qt-5/third-party-libraries.html

Zelas91 · 12 Oct 2018, 07:41

@VRonin said in Qt for plc:

http://doc.qt.io/qtcreator/creator-project-qmake-libraries.html
http://doc.qt.io/qt-5/third-party-libraries.html

this is understandable, but I asked about the compilation of the library, since my compiled library does not work

VRonin · 12 Oct 2018, 08:38

@Zelas91 said in Qt for plc:

but I asked about the compilation of the library

Then this is the wrong place to ask. Try asking on the project page, they should have instructions on how to build

since my compiled library does not work

How does not work? it probably is due to incompatible compilers.

Zelas91 · V VRonin 12 Oct 2018, 07:41

@VRonin
did everything according to the instructions for the library but when compiling it turns out 3 files * .def, * .lib, * .dll

VRonin · 10 Dec 2018, 09:15

That's correct, the .dll is the compiled binary, the .lib is the library your linker will need (the LIBS += part of the links above)

The .def should not be necessary, it's a module definition file that only works with Microsoft compilers (as far as I'm aware) and is an alternative to the _declspec( dllimport )/__declspec( dllexport ) directives.

You'll also need the .h files (or those in the includes folder) from the sources (this is the INCLUDEPATH += part of the links above)

Zelas91 · V VRonin 12 Oct 2018, 08:53

@VRonin
Thanks, I will try