Dear readers,
I am asking this question, because I want to use/extend an already available hmi system (does not need to be free of charge but should be open source) or to write a simple, new one (open source), as the existing (as far as I know) to not fullfill my requirements. I would like to use a standard file format, so that new components could be used by a wider community. Maybe this is already available. Therefore I have some questions do you.
- Main Question:
- Which HMI software would you suggest for visualisation only (no alarm logging etc.)? Or what are your experiences with such open source software?
- Requirements: I need a Human Machine Interface, where I can just show valves, vessels etc. which change the color depending on the state. But I also want to change the color of the pipes between the components, depending if the way is open or not. It would be nice if it is not a bitmap but vector graphics so that the definition of the layout is independent of the screen resolution. It should be possible, to click on it (touch screen) and to report the click event to the interface.
- Existing Software: As I do not want to invent the wheel again, I had a closer look on 4 x open source hmi software. But there are the following problems:
- Most of them use Java, which needs a lot of RAM and computing power. And it does not work on many embedded systems. And I must commit that I have only very few knowledge about Java (and for any reason which I do not know, it is not sympathically to me).
- Some do not have any documentation, one has to scan the source code in order to understand how it works. And the supplied examples to not work, as you need to install newer versions of the Virtual machine or another browser or ...
- Or it uses the QT Designer, which cannot draw pipes etc.
- Or the the last changes were made years ago and it is only half finished.
A common problem ist, that you can only use bitmaps and Widgets, but not connect them using a pipe. Another problem is, that some are so complex, as they have alarm logging etc. which I would like to have separated.
- Suggestions for new software:
- C++ classes
- separate interface class for graphic output so that most of it can be kept device independent. (so that one can use GTK, QT or Windows GDI).
- using a text file or, better, XML for definitions of the shape of valves...
- more comments would be appreciated ...
Greetings Ernst Murnleitner