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Posted to dev@plc4x.apache.org by Julian Feinauer <j....@pragmaticminds.de> on 2020/05/02 09:05:51 UTC

AW: Symbol metadata for connections

Hi,

this is a very good point.
You mean something like "getAllSymbols()" (which would only be possible in S7 case with either TIA File or S7Comm+ Protocol).
But totally makes sense for ADS or OPC UA.

Would love to see a Design Doc for that (starting with OPC UA and ADS gives quite a wide range of needs).

Julian
________________________________
Von: Christofer Dutz <ch...@c-ware.de>
Gesendet: Donnerstag, 30. April 2020 22:32
An: dev@plc4x.apache.org <de...@plc4x.apache.org>
Betreff: Re: Symbol metadata for connections

Hi Lukasz,

Initially we were planning on supporting a "browse" functionality alongside the "read", "write" and "subscribe" ...
might that be more what you are referring to?

Chris

Am 30.04.20, 21:54 schrieb "Łukasz Dywicki" <lu...@code-house.org>:

Hey,
I been going through some ideas what could be improved here and there
after doing my ADS try outs and come to following.

Current API for PlcConnectionMetadata offers few basic canRead,
canWrite, canSubscribe methods. It does not offer any api to read plc
kind or symbol, even if some drivers do discover device kind. For
comparison, with JDBC, we have few more options when we fetch metadata -
ie. java.sql.DataBaseMetadata#getTypeInfo, #getTables, #getColumns and
so on. I tend to opt for TypeInfo and Columns (symbols) as first class
citizens which we can make.

Currently protocols which can handle metadata requests can not support
discovery of available symbols cause there is no way to supply that.
This is something possible with ADS, for sure also with OPC UA. It
shouldn't be to hard to provide one.

Best regards,
Łukasz

Re: Symbol metadata for connections

Posted by Julian Feinauer <j....@pragmaticminds.de>.

Yes, that's the most important thing. In the end, the leads should be addressed that you simply add to request builder. But we should really carefully think about the api.

Would like to have @Matthias Milan Strljic<ma...@isw.uni-stuttgart.de> on board here. He knows lots of protocols.

Julian

Holen Sie sich Outlook für Android<https://aka.ms/ghei36>

________________________________
From: Christofer Dutz <ch...@c-ware.de>
Sent: Saturday, May 2, 2020 2:38:29 PM
To: dev@plc4x.apache.org <de...@plc4x.apache.org>
Subject: Re: Symbol metadata for connections

Hi,

but we should make it compatible with all protocols (in theory) so we shouldn't name things with OPC UA as reference and try to map things to that.
Would be cool if someone could describe how this mechanism works in the different protocols and how the operations are named.

Chris

Am 02.05.20, 11:06 schrieb "Julian Feinauer" <j....@pragmaticminds.de>:

    Hi,

    this is a very good point.
    You mean something like "getAllSymbols()" (which would only be possible in S7 case with either TIA File or S7Comm+ Protocol).
    But totally makes sense for ADS or OPC UA.

    Would love to see a Design Doc for that (starting with OPC UA and ADS gives quite a wide range of needs).

    Julian
    ________________________________
    Von: Christofer Dutz <ch...@c-ware.de>
    Gesendet: Donnerstag, 30. April 2020 22:32
    An: dev@plc4x.apache.org <de...@plc4x.apache.org>
    Betreff: Re: Symbol metadata for connections

    Hi Lukasz,

    Initially we were planning on supporting a "browse" functionality alongside the "read", "write" and "subscribe" ...
    might that be more what you are referring to?

    Chris


    Am 30.04.20, 21:54 schrieb "Łukasz Dywicki" <lu...@code-house.org>:

        Hey,
        I been going through some ideas what could be improved here and there
        after doing my ADS try outs and come to following.

        Current API for PlcConnectionMetadata offers few basic canRead,
        canWrite, canSubscribe methods. It does not offer any api to read plc
        kind or symbol, even if some drivers do discover device kind. For
        comparison, with JDBC, we have few more options when we fetch metadata -
        ie. java.sql.DataBaseMetadata#getTypeInfo, #getTables, #getColumns and
        so on. I tend to opt for TypeInfo and Columns (symbols) as first class
        citizens which we can make.

        Currently protocols which can handle metadata requests can not support
        discovery of available symbols cause there is no way to supply that.
        This is something possible with ADS, for sure also with OPC UA. It
        shouldn't be to hard to provide one.

        Best regards,
        Łukasz

Re: Symbol metadata for connections

Posted by Christofer Dutz <ch...@c-ware.de>.

Hi,

but we should make it compatible with all protocols (in theory) so we shouldn't name things with OPC UA as reference and try to map things to that.
Would be cool if someone could describe how this mechanism works in the different protocols and how the operations are named.

Chris

Am 02.05.20, 11:06 schrieb "Julian Feinauer" <j....@pragmaticminds.de>:

Hi,

this is a very good point.
You mean something like "getAllSymbols()" (which would only be possible in S7 case with either TIA File or S7Comm+ Protocol).
But totally makes sense for ADS or OPC UA.

Would love to see a Design Doc for that (starting with OPC UA and ADS gives quite a wide range of needs).

Hi Lukasz,

Initially we were planning on supporting a "browse" functionality alongside the "read", "write" and "subscribe" ...
might that be more what you are referring to?

Chris

Am 30.04.20, 21:54 schrieb "Łukasz Dywicki" <lu...@code-house.org>:

Hey,
I been going through some ideas what could be improved here and there
after doing my ADS try outs and come to following.

Best regards,
Łukasz