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Query Object |
To configure a Query object to retrieve data from an OPC UA Server using an OPC UA Driver, follow these procedures:
1.Select an OPC UA Driver on Query's Define Database Server window.
Define Database Server window
2.The following window is then displayed, allowing a Query configuration.
Fields tab
The available options on the Fields tab are described on the following table.
Available options on the Fields tab
Option |
Description |
---|---|
Raw Data |
This Query returns data as stored on an OPC UA Server, similar to Storage's CompressedDataStartEndTime query. In this mode, only one OPC UA Tag can be retrieved at a time, also returning this value's quality |
Processed Data |
This Query returns aggregated data inside a time interval, similar to Storage's SampledData and CalculatedData queries. In this mode, several OPC UA Tags can be retrieved at once, although not returning this value's quality. Several aggregation functions can be used, such as average, maximum, and interpolation, among others. Different functions can be used for each OPC UA Tag and one OPC UA Tag can appear several times in a Query, with different aggregation functions. Elipse E3 only lists standard functions, without searching for OPC UA Server's specific functions or filtering functions not supported by an OPC UA Server. This Query may fail when selecting a function not supported by an OPC UA Server |
Adds a field |
Adds one or more OPC UA Tags from an OPC UA Server |
Deletes the selected field(s) |
Deletes the selected OPC UA Tag from this Query |
Updates all fields Ids |
Forces an update on OPC UA Node Identifier (NodeId) values |
Id |
Type of OPC UA Node Identifier (NodeId) on an OPC UA Server |
Columns |
Path of an OPC UA Tag on an OPC UA Server |
Title |
Name of an OPC UA Tag on an OPC UA Server |
Function |
Function used on this OPC UA Tag. This column is only available when the Processed Data option is selected |
When clicking Adds a field , the following window is then displayed, allowing to select the existent OPC UA Tags on an OPC UA Server.
Selecting OPC UA Tags
The Variables and Visualize tabs have the same behavior described on Query chapter.