This annex is intended to provide some guidelines on how to expose a ChemometricModel prediction service on an existing ADI server.
|Scenario steps||Interface used|
|1. The client application logs on ADI Prediction server||OPC UA CreateSession|
|1. The client application reads model from disk and loads them in ADI Prediction server||OPC UA AddNode and write services|
|1. ADI Prediction server exposes all model structures in its address space||OPC UA address space + ADI data types|
|1. The client application logs off ADI Predictor server||OPC UA CloseSession|
|1. The same or another client application logs on ADI Prediction server||OPC UA CreateSession|
|1. Client application identifies loaded models and their structure||OPC UA Browse address space + ADI data types|
|1. Client application calls MVAPredict () method with the appropriate input parameters,||OPC UA/ADI method call service + ADI data types|
|1. ADI Prediction server computes predicted values using vendor native libraries.||Vendor specific native libraries|
|1. Application reads predicted values from MVAPredict () method output parameters.||OPC UA/ADI method call service + ADI data types|
|1. Repeat steps 7 to 9 for each model|
|1. Application logs off from ADI Prediction server||OPC UA CloseSession|
Many applications may execute Steps 5 to 11 concurrently.
- The client application may pass the input values and received predicted values using OPC UA/ADI address space. However, this approach does not scale up well in multi-user environment because a prediction server is expected to serve many users concurrently which make synchronization almost impossible.
- In custom / dedicated configurations, the ADI Prediction server loads a predefined set of models, so client applications can use them immediately.