In Figure 3, the ProcessValueType and its supertypes with key InstanceDeclarations is shown. The mandatory 3:SignalTag contains a unique name as defined by OPC 30081. The optional 3:ZeroPointAdjustment Method allows to set a zero point as defined in OPC 30081. The ProcessValueType adds a reference to the ZeroPointAdjustmentEventType. Events of this EventType are generated, when the zero-point adjustment is executed (see 8.1). The 3:AnalogSignal defined in OPC 30081 is extended with additional meta data. The ProcessValueType is defined in 7.1, having additional optional components like process value setpoint and alarm information.
This ObjectType was introduced to bind functionality to the process value that cannot be added to the 3:AnalogSignal directly, like Objects and Methods.
