DWIS-Blackboard-Samples

Sample .NET 8 console apps showing how to interact with the DWIS semantic blackboard using the reference client.

Samples

• Samples/AcquireSignals/: subscribe to signals via SPARQL query, print values periodically.
• Samples/GetQueryResults/: resolve SPARQL queries and display results (includes sample OPC UA config in config/).
• Samples/InjectManifestAndWriteData/: inject a manifest, then update provided variables periodically (sample OPC UA config in config/).
• Samples/Samples.sln: solution for building all samples.

Build & run

From Samples/:

• Build: dotnet build Samples.sln
• Run a sample, e.g.: dotnet run --project AcquireSignals/AcquireSignals.csproj

Prereqs

• DWIS Blackboard reachable via OPC UA.
• Quickstarts.ReferenceClient.Config.xml in each sample's config/ points to your server; adjust endpoints/credentials as needed. Important: you may have to change the Copy to Output Directory property of the configuration file to Copy if newer, or Copy always
• Reference client packages resolved via NuGet;

Examples

GetQueryResults

• print-query SPP: shows the SparQL query asking for a SPP signal. The result should look like:

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX ddhub: <http://ddhub.no/>

SELECT ?signal
WHERE {
                        ?dataPoint ddhub:HasDynamicValue ?signal .
                        ?dataPoint rdf:type ddhub:SPP .
}

• print-query SPP -m true -d true: shows the SparQL query asking for a Measured SPP, and the corresponding data point in addition to the signal:

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX ddhub: <http://ddhub.no/>

SELECT ?signal ?dataPoint
WHERE {
                        ?dataPoint ddhub:HasDynamicValue ?signal .
                        ?dataPoint rdf:type ddhub:Measurement .
                        ?dataPoint rdf:type ddhub:SPP .
}

• print-query-results SPP -d true -m true: displays the results of the query. Depending of the contents of your blackboard, the result can look like:

┌───────────────────────────────────────────────┬─────────────────────────────┐
│ ?SIGNAL                                       │ ?DATAPOINT                  │
├───────────────────────────────────────────────┼─────────────────────────────┤
│ http://ddhub.no/openLAB/Variables/openLAB.SPP │ http://ddhub.no/openLAB/SPP │
└───────────────────────────────────────────────┴─────────────────────────────┘