When running the AS4toAs6-migration script, I received a message stating that the LoopCont library had been replaced by the “mapp Temperature” and “mapp Controls Tools” libraries.
Does anyone know if there is a more “open” approach to replacing this library than using mapp technology packages?
Are there other base libraries that offer the same functions as the existing LoopCont library?
Hello Niklas Richter:
One option I can see would be using LoopContR : Function blocks and functions
There a few differencies, the main would be the LoopContR uses floating operation (REAL) and the LoopCont uses integer based operation.
The again, as the help itself indicates, this library is replaced by mechantronic libraries.
Hello @Niklas_Richter ,
LoopCont has become obsolete since modern PLC uses floating point units inside their processors.
Integer arithmetic therefore offers no advantage and is likely to be slightly slower.
If you change to mapp Controls you will get access to straightforward control libraries (‘MT…’)
Most of these libraries are free of charge (no license)
Licensing
@christoph.hilchenbac
We have a broad C code base which we use on all of our plants.
Since we also have to maintain und sometimes extend old plants, we work with versions from AS 2.7 up to AS 4.12.
Our code contains uses a lot of functions from the Loopcont as well as Loopconr, which work well.
That makes it impossible for us to move ta AS 6 with our new projects.
I actually don’t understand, why the Loopcont library gets not provided anymore for AS 6, since it only contains mathematical algorithms an it has no hardware or AR dependencies and I ask B&R to make it available again for legacy code reasons.
Hi @Michael.Uray ,
I completely understand that it takes some effort to migrate such projects now.
Many hardware and software products were discontinued during the transition to AS 6 due to the CRA topic.
The LoopCont library is over 20 years old, and the developer responsible for it has been retired for several years.
If we were to continue making this library available in the current Automation Studio, we would be committing to maintaining it for at least 10 years.
Since we don’t have a “deprecated” flag, there is a risk that this library could also be used in new projects.
I hope you understand.
Do you see any chance that the source code of this library will be available in B&Rs public Github repository? This way it would be still available for those who rely on it and B&R won’t need to maintain it.
My biggest problem in switching to the new MT-Libraries or even the LoopConR is the lack of an existing machine. Those are running in the field for many years with well working PID parameters. Switching to another library would make it necessary to travel to the customers for optimizing the controllers and there are plenty of them in use.
As I wrote, we can not migrate since we have to maintain our code for all the older Automation Studio versions as well.
So it is actually a very well-developed product. I don’t see any reason to maintain it since it is working fine over years I think there was already no development in the past years+.
It only contains mathematical algorithms, so I don’t see any problem with the CRA.
So just keep it in as it as, which maintenance work would you expect with it?
That sounds like a good idea to me. The software is obviously nothing worth for B&R, so why not make it public?
We have already proposed to our B&R sales guy in January to send us the source code to solve that issue, but we never received a feedback on that matter.
We also have the same issue, that we experienced of the years PID parameters which fit to our applications and I don’t see a reason to re-evealuate all the settings for all applications.
Independent from that, the new libraries still do not support all the same functionality as the LoopCont library:
So I ask to just add it to the AS 6 version and don’t further develop it.
I fully agree with this point.
From my perspective, there shouldn’t be any issue with CRA here, since we’re essentially talking about mathematical functions - there’s no inherent risk involved.
It would be highly appreciated if the library (at least LoopContrR) were made available as open source, or even better, if it continued to be actively maintained.
I’d also like to emphasize that you’re not the only customers affected - others would strongly welcome B&R continuing support for this instead of discontinuing the library.
An open-source approach could be a reasonable compromise.
That said, a simple, lightweight library without dependency on mapp components would still be a very desirable alternative from B&R.
I think not every fundamental function needs to rely on mapp technologies.
I’m converting an old prj with no clear specification of all use cases so I’m more comfortable to be volunteer on maintaining old libraries rather than use new libraries where I can’t test all situations.
Ciao
Valerio