Question to FORTE

[vwitti]

Dear 4diac developers,

we have ported on our hardware (STM32N6570) the FORTE run-time with ThreadX RTOS and at a first glance it is working satisfying.
I have some question ideas regarding FORTE

• Performance CODESYS vs. 4diac FBs
  This is more my personal interest, I have worked for more than 13 years in CODESYS development with companies like ABB or Lenze. I know the CODESYS compiler very well, and at least to my last knowledge this compiler is not very performant. Your approch to generate C++ code, which is compiled using a high optimizing g++ compiler, should result in a significant performance advantage when running on the same hardware base. Did you ever made some comparisions between CODESYS and FORTE runtime. As I said in the beginning, this is just a personal interest.

• Load FB code during run-time dynamically
  In current design state, all FBs are defined in 4diac IDE and the code generator gives a .cpp implementation, which you add to your firmware, so you are able to generate a customer network in the 4diac IDE. From my point of view, an important feature of any PLC is the possibility to download a FB during run-time. since we have .cpp we would be able to compile this code "relocatable" and download this objects into RAM and execute from here. For this use-case the calling inside the FORTE run-time should also have a dynamic mode, e.g. write a pointer list of new FBs after download. My question is: Is there an idea existing to extend FORTE in such a way, and second do you have an idea or estimation how difficult this could be. This is in the current stage not a feature request, but just interesting for me, since this is an important feature for our customer, and I would be happy to have a bried discussion on a community meeting.

• 4diac Codegenerator as Key-Shortcut or by script
  In current version you have to do a lot clicks to run the code generation (Export). Is there a way to do the Export via a key-shortcut or trigger it by a script or something else.

best regards
Volker Wittelsberger

[mx990]

I am happy to hear that 4diac FORTE is working to your satisfaction so far. I have split my answers to your questions into multiple comments below, so that we can have independent threads of conversation if needed. In the future, I would ask you to please keep each issue or discussion on one topic only. This makes it easier for others to find topics of interest to them and join in the conversation.

[mx990]

• Performance CODESYS vs. 4diac FBs
  This is more my personal interest, I have worked for more than 13 years in CODESYS development with companies like ABB or Lenze. I know the CODESYS compiler very well, and at least to my last knowledge this compiler is not very performant. Your approch to generate C++ code, which is compiled using a high optimizing g++ compiler, should result in a significant performance advantage when running on the same hardware base. Did you ever made some comparisions between CODESYS and FORTE runtime. As I said in the beginning, this is just a personal interest.

I am currently not aware of any performance comparisons between CODESYS and 4diac, but maybe someone else knows of any.

[azoitl]

We have done some performance evaluations of 4diac FORTE as part of a master's thesis some 13 Years ago. However as part of this master's thesis we also noticed that it is hard to compare IEC 61499 applications with existing IC 61131-3 from a performance point.

If you have an event heavy application like any sequence control then an IEC 61499 will implemented completely different and also behave completely different then an IEC 61131-3 application. So comparing both would be hard. Especially as in such situations most parts of the IEC 61499 application would "sleep" all the time.

Where it could make sense to compare is if you have algorithm heavy blocks. Here it could be interesting to compare. Or maybe just even measure 4diac FORTE performance and assess it. While C++ allows you to write very high performance code, in my experience it is also very easy to write code that looks like it will be high performance but then is not.

So I would use this here as a call out for large FBs with many lines of ST code that could be assessed. The more ST statements the better:

• loops
• conditions and switches
• method calls
• function calls
• ...

[MartinMelikMerkumians]

To add here, the execution speed of an IEC 61131 FB inside a task is rather "irrelevant" for the execution time, as the scan cycle determines the perceived speed. The faster your POUs are executing the more you can cramp into one scan cycle, whereas in IEC 61499 FB execution speed directly influences perceivable event flow speed in an IEC 61499 application

[mx990]

• 4diac Codegenerator as Key-Shortcut or by script
  In current version you have to do a lot clicks to run the code generation (Export). Is there a way to do the Export via a key-shortcut or trigger it by a script or something else.

You can automatically export all types during build using the 4diac Export Builder. As long as you have Build Automatically selected under Project in the main menu, this will happen each time you save a type. It can be enabled in the project properties (right click on your project and select Properties):

[vwitti]

Hi,

thank you for your quick answer, i had a few days off, so I could not answer before. I don't see the menu entry, not 3.0.2 or 3.1 in Windows or Linux. Do I have to start 4diac IDE in a diffrent mode ? Please see attached screenshot
best regards
volker

[mx990]

Your screenshot shows the Preferences, which are settings for your Eclipse workspace. The Type Export properties are project-specific and you can find them by right clicking on your project and selecting Properties.

[vwitti]

Hi,

sorry for the confusion, I found it, both menus look quite similar, I looked into the wrong menu
best
volker

[mx990]

No worries, they do indeed look very similar. I am glad you found it and hope the automatic export is working for you now.

[azoitl]

Maybe to add here they are on purpose similar so that the same preferences that are available on workspace level are also in the same structure on project preferences. This preference though is only a project preference as it does not make really sense on workspace level.

[mx990]

• Load FB code during run-time dynamically
  In current design state, all FBs are defined in 4diac IDE and the code generator gives a .cpp implementation, which you add to your firmware, so you are able to generate a customer network in the 4diac IDE. From my point of view, an important feature of any PLC is the possibility to download a FB during run-time. since we have .cpp we would be able to compile this code "relocatable" and download this objects into RAM and execute from here. For this use-case the calling inside the FORTE run-time should also have a dynamic mode, e.g. write a pointer list of new FBs after download. My question is: Is there an idea existing to extend FORTE in such a way, and second do you have an idea or estimation how difficult this could be. This is in the current stage not a feature request, but just interesting for me, since this is an important feature for our customer, and I would be happy to have a bried discussion on a community meeting.

We already support loading additional types into 4diac FORTE at run time using shared libraries. However, this relies on support by the operating system and is currently only supported on Posix and Windows. If you want to try it out yourself, you can build both 4diac FORTE and your modules according to Building your own 4diac FORTE and then load your modules using the -l option.

Internally, all types are self-registering themselves in the FORTE runtime, so this should also work regardless of your operating system, as long as you are able to somehow load and initialize the executable code. In other words, you will need a dynamic linker for your particular operating system and target platform. Afterwards, it should just be a matter of how to download the code and pass it on to the dynamic linker.

Aside from that, there is also support for a dynamic deployment of FB types using a Lua interpreter, but this is currently defunct.