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"SubscribeDataChange" using the read function

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25 Nov 2019 14:39 #8016 by Moien
Dear all,


I am reading more than 300 different variables with different node IDs from the OPC UA Server. My application is runing 24/7 and I am getting always new variables on the OPC UA Server. I used the "SubscribeDataChange" function (every 1000 milliseconds) to get the new values every second, otherwise the values won't be updated in my Delphi application.
Using "SubscribeDataChange" in a for loop (shown in the following) put lot of load on the CPU! is there any posibility to update all the variables at the same time, something like "Multipple DataChange"?

for I := NoV_DB100 to Length(OPCServerItemArray)-1 do begin
Name := OPCServerItemArray.Source + '.' + OPCServerItemArray.ItemName;
NodeID := 'nsu='+ nsu + ';s=Local Items.' + Name;
OPCUAClientRead.SubscribeDataChange(Url_String,NodeID, 1000);
end;


Best regards,
Moien

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