EURange
EURange is a Property of an AnalogItemType Variable holding a Range structure with the Low and High engineering-unit limits of the value. It is what a percent deadband is computed against and what an HMI uses to scale a bar or a trend axis. Without it, percent deadbands and range-based quality checks cannot work.
Where it sits in the model
AnalogItemType, defined in Part 8, adds three Properties to a Variable: EURange (mandatory), EngineeringUnits and InstrumentRange (both optional). EURange is the normal operating or display range; InstrumentRange is the sensor's full physical span. A value outside EURange but inside InstrumentRange is legitimately reportable, and some servers flag it with UncertainEngineeringUnitsExceeded.
What depends on it
Percent deadbands, HMI autoscaling, alarm limit defaults, normalisation in analytics pipelines, and any client that wants to render a gauge without hardcoded constants. It is one node read per tag at startup and it removes an entire class of configuration duplication - which is why a server that models analogue values as AnalogItemType is markedly cheaper to integrate than one that exposes bare numbers.
Most PLC servers do not provide it
Tags exported from a PLC symbol table generally arrive as BaseDataVariableType with a DataType and nothing else. Adding EURange means modelling the tag properly in the server or gateway - in TIA Portal, in a Kepware or Ignition tag definition, or in a companion-specification-based information model. That work is what makes percent deadbands and self-describing dashboards possible later.
Example
A properly modelled analogue value
Line3/Extruder/MeltTemperature : AnalogItemType (Double)
|- EURange Range { Low: -50.0, High: 400.0 }
|- EngineeringUnits EUInformation { NamespaceUri: UNECE, UnitId: <CEL>,
DisplayName: "degC", Description: "degree Celsius" }
|- InstrumentRange Range { Low: -100.0, High: 500.0 }
1 percent deadband on this node = 4.5 degC (450.0 span x 0.01)
Compare: ns=3;s="Line3"."T_melt" : BaseDataVariableType - no properties at all.Defined in: Part 8 - Data Access defines AnalogItemType, EURange, InstrumentRange and EngineeringUnits.
Last verified 7 September 2026 against OPC UA 1.05.07. OPC UA Connect is an educational resource and is not affiliated with the OPC Foundation.