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From Julian Feinauer <>
Subject Re: [DISCUSS] The State and Future of PLC4X
Date Mon, 06 May 2019 12:11:34 GMT
Hi Matthias,

first, +1 for OPC UA Integration (Both ways, Driver and Bridge) and another +1 for bringing
it to the list : )
As I recall Chris is considering treating the OPC UA Bridge thing as a prioritized Ticket,
so its really best if you get in touch.

The other thing which comes along with the OPC UA Driver is that we should extend / change
the API a bit to handle Complex fields more natively (or objects, so to say).
Lukasz also had some nice ideas so perhaps we create a Confluence page for that and you, Matthias
could kind of keep that in sync with your work on the Client.

What do others think?


Am 06.05.19, 13:35 schrieb "Strljic, Matthias Milan" <>:

    Hi Chris and Rolf, 
    i played yesterday a bit with Milo and PLC4X and would make a integration of Milo in the
PLC4J version in this week. There u would have to excuse my noobish coding after 8 Months
of only PP-Engineering. It would be first limited to the Base-Types and could be later replaced
by some nice generated driver??? ❤ #GenDriverHype
    @Chris: The EPL of Milo is there in a binary form not a problem in PLC4X or? (
    As Julian earlier mentioned we also playing a bit around with an OPC UA Bridge. It progresses
very slowly (just in a design stage) and perhaps we could synch there a bit 😊
    Matthias Strljic, M.Sc.
    Universität Stuttgart
    Institut für Steuerungstechnik der Werkzeugmaschinen und Fertigungseinrichtungen (ISW)
    Seidenstraße 36
    70174 Stuttgart
    Tel: +49 711 685-84530
    Fax: +49 711 685-74530
    -----Original Message-----
    From: Christofer Dutz <> 
    Sent: Monday, May 6, 2019 10:25 AM
    To:; Julian Feinauer <>; Rolf Wutzke
    Cc: Ralf Kölle <>
    Subject: Re: [DISCUSS] The State and Future of PLC4X
    Hi Rolf,
    I sort of didn’t see the intermediate emails on the list, so replying to multiple ones
here … as I manually had to release this one, I guess you are not all subscribed to the
mailing list. Please do so by sending an email to<>
… otherwise I will have to manually release every email you send ;)
    As Julian mentioned, the meetup date has been set to 24. May 2019 in our codecentric office
in Franfurt.
    Regarding OPC-UA … I think we have to distinguish between OPC-UA Server and Client functionality.
While OPC-UA Client is definitely something we have on our plan (Being able to connect to
OPC-UA enabled devices), also an OPC-UA Bridge utility have been discussed (Connect an OPC-UA
client to this server and in the backend this uses PLC4X to connect to non-OPC-UA devices)
and its implementation might even start earlier (Will be decided in the next few days if this
gets prioritized up).
    We already have the Specs for Profinet here at codecentric and Ethercat is also on our
ToDo list. Howerver for Ethercat we haven’t got the specs yet.
    Currently we are working on preparing a new way of creating drivers therefore we haven’t
added new protocols for quite some time. But I hope we’ll get that finished soon and be
able to start mass-producing new drivers as soon as that’s done (It would have been a nightmare
to implement, maintain and sync drivers in currently 4 languages, therefore we are working
on a driver specification and generation tooling that will automatically keep all driver implementations
in sync).
    Regarding OPC-UA: I think we could probably implement quite an efficient OPC-UA driver,
if we limit the OPC-UA features we support. So instead of providing all the features, if we
concentrate on the Data-Exchange part, I bet this could be quite efficient. But we’ll see
how they perform as soon as we have them … but it wouldn’t be the first time we out-perform
the insanely expensive industry solutions ;-)
    Von: Rolf Wutzke <>
    Antworten an: "" <>
    Datum: Montag, 6. Mai 2019 um 10:04
    An: Julian Feinauer <>
    Cc: "" <>, Ralf Kölle <>
    Betreff: Re: [DISCUSS] The State and Future of PLC4X
    Hi Julian,
    thanks for adding us here.
    We are currently not working with PLC4X but the topic looks quite promissing to jump onto.
At the moment we have a lot of PLX connection implementations done by our own which is ...
    Are there any news in regard to the meetup date? I put my availability in the doodle,
would be really happy to discuss the topic face-2-face with the rest.
    Am Do., 18. Apr. 2019 um 10:29 Uhr schrieb Julian Feinauer <<>>:
    Hi all,
    Fedlbus is a good Keyword.
    Yesterday I met with Ralf Koelle and Rolf Wutzke from scitis / sotec and they were quite
interested in these two.
    @Ralf, @Rolf: I took the freedom to take you in CC. Do you already have a working stack
for these protocols?
    Am 18.04.19, 10:14 schrieb "Bjoern Hoeper" <<>>:
        Hi erveryone,
        I agree with Markus because OPC UA is somewhat universal. If we want something open
source there is a stack which is quite evolved already:
it is maintained by a bunch of institutes (one of them is the Process Control Institute in
Aachen). So we should at least think about an adapter to OPC UA. The thing we would need to
prove is that we can really get faster than the vendor OPC UA server.
        Another thing that I think is promising and needed is adaptation to field bus systems
like Profinet and EtherCAT because they provide good performance and a quite general applicability.
And are at least not vendor specific.
        Best Regards
        -----Ursprüngliche Nachricht-----
        Von: Markus Sommer <<>>
        Gesendet: Donnerstag, 18. April 2019 09:06
        Betreff: AW: [DISCUSS] The State and Future of PLC4X
        Hi all,
        I was at the Hannovermesse and the industry clearly relies on OPC UA. If PLC4x could
realize a very fast OPC UA, this would be a massive advantage over other manufacturers.
        Best regards
        Freundliche Grüße
        Markus Sommer
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        -----Ursprüngliche Nachricht-----
        Von: Julian Feinauer <<>>
        Gesendet: Mittwoch, 17. April 2019 09:07
        Betreff: [DISCUSS] The State and Future of PLC4X
        Hi all,
        as we had a lot of non-technical discussions and topics the last time (the coming
of age of a software project, I guess) it’s time for us to go back to the real fun part
and do technical shit.
        I had a lot of discussions (on list and off list) with several people like Chris,
Matthias, Björn, Tim and others and wanted to share my thoughts on the future of PLC4X as
I see it (from a solely technical perspective).
        Currently, I see several “fronts” or centers of activity (or where I think we
should spend it).
          *   Language adoption – We should define and deliver APIs and bindings for other
languages to bring what we currently have to other people and other communities. The activities
we have there are currently (from my head): Markus and C++, Björn who wanted to investigate
C# and the “Interop Server” which I played around a bit (in fact, Matthias made a python
binding yesterday…)
          *   Driver Generation – This is a well-known Topic which is currently driven by
Chris. This is a large topic, which includes
             *   Model Generation (currently dfdl and state-xml)
             *   Templates for many languages (will partially derive from above)
             *   A build process, to wire both together
             *   Some kind of Test Suite to check the correct generation of drivers
             *   Automated Documentation / Spec Generation (!!
          *   Ecosystem / Tools – We have a set of tools that are based on PLC4X and which
enable to do things which where unthinkable before. Some are
             *   Scraper – A tool to scrape massive amounts of data from multiple PLCs based
on a yml configuration, this is mostly driven by Tim
             *   OPC UA Server – Yet to come. Maps OPC UA requests to PLC4X requests which
then go native to the PLCs. Matthias started some work on this, Tim looked over it and I think
Chris plans on implementing something here also
             *   We had multiple discussions about tools that “guess” something about
locations of variables or their types. Chris brought that up yesterday and plans to do something
there, Matthias and I discussed this several times and we plan to also do something with one
or two students there
          *   New programming models – As plc4x is open, it allows us to implement new programming
models on top of it. The best example I can give is OPM, the JPA equivalent of PLC4X. The
idea is to work with POJOs and annotations and EntityManagers (as Beans) and have a “type
safe” and Business-esque way to communicate with PLCs.
        Here I see a lot of potential and possible next steps could be (discussed by Matthias
and me)
             *   “Richer” Typesystem (not just primitives and Arrays as currently) which
covers complex objects
             *   Mapping of complex objects from POJOs to PLC segments (Like structs in S7
or ADS)
             *   Auto-generation of annotated POJOs from PLC programs (much like JPA or the
C# ORM does that based on an existing database). This could be a “killer-feature” as it
would really allow type-safe end to end communication with the plc with zero plc specific
        Other Topics in this area that can be named are
             *   A connection pool to share / reuse connections for efficiency (which was
implemented by Sebastian and is absolutely crucial for us!)
             *   A central monitoring component (similar to how a Webserver monitors each
side access and the results and latencies and so..), I am currently working on this and hope
to provide a PR soon
        Of course, all of this is solely based on my personal opinion or things that came
out in discussions with other involved people.
        For me, this structure makes sense and perhaps it helps us to “broaden” our scope
a bit from the initial focus (drivers, drivers, drivers) to the new picture which evolved
over the last to years.
        Of course, feel free to agree, disagree or participate with other opinions.
        PS.: I could offer to bring this in a more “presentable” form and prepare a short
“overview” talk about this for the next meetup, if interesting
    Rolf Wutzke | SOTEC |<> | T +49 7033 5458
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