OPC UA client connection setup ?

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  • #14555
    zzz
    Participant

    I saw this document https://rapidscada.net/doc/content/latest/en/use-cases/opc-standard.html, but still not quite sure.

    Just to confirm that when configuring OPC UA client, all other settings, in Line Options tab can be ignored, only the following is necessary?
    – setting Driver to DrvOpcUa
    – clicking Properties button and setting the tags

    What about the timeout, delay, time, period, string address or host name, name ?

    • This topic was modified 2 weeks, 5 days ago by zzz.
    #14557
    zzz
    Participant

    Also on the TagName thing, for the first time, I need to join two OPCUA string values together. I am not sure if formula like below will be suffice.

    
    Data Len:  '30'
    Data Type: 'Ascii Str'
    TagCode: ''
    TagName: ''
    Formula Enabled: 'true'
    Formula: Val('TagCode1')+Val('TagCode2')
    

    TagCode1, TagCode2 are not referenced anywhere in Channels, only configured in ScadaComm OPC UA Properties.

    #14559
    zzz
    Participant

    Forgot to tick for notify. 😀

    #14562
    Mikhail
    Moderator

    That article is about configuring OPC Classic for Rapid SCADA 5.

    > What about the timeout, delay, time, period, string address or host name, name ?
    Time and period do not work. Address is ignored. Delay is used internally. I recommend to use the default values.

    > Also on the TagName thing, for the first time, I need to join two OPCUA string values together.
    It would be easier if you get a string in a one OPC UA tag instead of joining channels. Concatenation of string channels is possible, but the formula may be tricky.

    #14570
    zzz
    Participant

    Could you define the tricky tricky(R) ?
    My project this time is an extension of an existing project, otherwise I wouldn’t get into OPC UA I guess. I think it’s better I don’t fiddle with the KepwareEx service, since the other client software that KepwareEx is installed for seems not so robust. I don’t want to break it. And I have just learn this much about OPC UA.
    I’d rather try my luck with dotnet. I believe my previous attempts on formula in RS5 is more twisted :-D.

    #14582
    Mikhail
    Moderator

    The idea of the formula is below.
    String are encoded in Unicode, split into byte arrays and save into channels that have Double data type.
    In a formula you need to convert Doubles back into strings. Then join, and convert from string to double.
    If a channel has length > 1, the Server internally creates several channels with sequent numbers, so you can access their data as usual.
    In the Script table, find the [5] Strings functions. They will be useful for your purpose.

    #14583
    Mikhail
    Moderator

    Note that you can write some info to a text file from script to debug your formula.

    #14606
    zzz
    Participant

    ok. I give up. I thought I could poll data into db with RS6, it seems currently storing str type data is not supported in postgres or influxdb archive.
    I think adding an external string resource table and storing the string offset maybe easier than the current way, and easier to map to current supported dbs, only my shallow guess though.

    • This reply was modified 2 weeks, 1 day ago by zzz.
    #14613
    Mikhail
    Moderator

    When you use channels of string type, despite the archive type like *.dat, InfluxDB or PostgreSQL, channel data are stored as doubles. To get the string from double, it should be decoded.
    I can help you to create and debug the formula, but I will not do it by myself.

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