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28. Control Updater Datum Filter

The Control Updater Datum Filter provides a way to update controls with the result of an expression, optionally populating the expression result as a datum property.

This filter is provided by the Standard Datum Filters plugin, which is provided by the solarnode-app-datumfilters package in SolarNodeOS.

28.1 Settings

Control Updater filter component settings The screen shot shows a filter that would toggle the /power/switch/1 control on/off based on the frequency property in the /power/1 datum stream: on when the frequency is 50 or higher, off otherwise.

Each filter configuration contains the following overall settings:

Setting Description
Service Name A unique ID for the filter, to be referenced by other components.
Service Group An optional service group name to assign.
Source ID A case-insensitive pattern to match the input source ID(s) to filter. If omitted then datum for all source ID values will be filtered, otherwise only datum with matching source ID values will be filtered.
Required Mode If configured, an operational mode that must be active for this filter to be applied.
Required Tag Only apply the filter on datum with the given tag. A tag may be prefixed with ! to invert the logic so that the filter only applies to datum without the given tag. Multiple tags can be defined using a , delimiter, in which case at least one of the configured tags must match to apply the filter.
Control Configurations A list of control expression configurations.

Each control configuration contains the following settings:

Setting Description
Control ID The ID of the control to update with the expression result.
Property The optional datum property to store the expression result in.
Property Type The datum property type to use.
Expression The expression to evaluate. See below for more info.
Expression Language The expression language to write Expression in.

28.2 Expressions

See the Expressions guide for general expressions reference. The root object is a DatumExpressionRoot that lets you treat all datum properties, and filter parameters, as expression variables directly.