The JoiningDataVariableType is a subtype of the BaseDataVariableType. It is to describe common sematic required for variables in the system. In this version of the specification, it provides information about physical quantity and Engineering Units. It is formally defined in Table 188.

Table 188 – JoiningDataVariableType Definition

Attribute		Value
BrowseName		JoiningDataVariableType
IsAbstract		False
ValueRank		−1 (−1 = Scalar)
DataType		BaseDataType
References	NodeClass		BrowseName		DataType	TypeDefinition	Other
Subtype of the 0:BaseDataVariableType defined in OPC 10000-5.
0:HasComponent	Variable		PhysicalQuantity	0:Byte		0:MultiStateDiscreteType	O, RO
0:HasProperty	Variable		0:EngineeringUnits	0:EUInformation		0:PropertyType	O, RO
Conformance Units
IJT Engineering Units

The component Variables of the JoiningDataVariableType have additional Attributes defined in Table 189.

Table 189 – JoiningDataVariableType Attribute values for child nodes

BrowsePath	Value Attribute
PhysicalQuantity 0:EnumStrings	OTHER TIME TORQUE ANGLE IMPULSE DISTANCE AREA VOLUME FORCE PRESSURE VOLTAGE CURRENT RESISTANCE POWER ENERGY MASS TEMPERATURE FREQUENCY JOLT VIBRATION NUMBER LINEAR_SPEED ANGULAR_SPEED LINEAR_ACCELERATION ANGULAR_ACCELERATION TORQUE_SPEEDTORQUE_ACCELERATION TORQUE_PER_ANGLE_GRADIENT TORQUE_PER_ANGLE_GRADIENT2

PhysicalQuantity is to determine the type of the physical quantity associated to a given value(s). It has the following pre-defined values which shall be used for each instance of this type.

• 0 – OTHER
• 1 – TIME
• 2 – TORQUE
• 3 – ANGLE
• 4 – IMPULSE
• 5 – DISTANCE
• 6 – AREA
• 7 – VOLUME
• 8 – FORCE
• 9 – PRESSURE
• 10 – VOLTAGE
• 11 – CURRENT
• 12 – RESISTANCE
• 13 – POWER
• 14 – ENERGY
• 15 – MASS
• 16 – TEMPERATURE
• 17 – FREQUENCY
• 18 – JOLT
• 19 – VIBRATION
• 20 – NUMBER
• 21 – LINEAR_SPEED is the change of distance over time.
• 22 – ANGULAR_SPEED is the change of angle over time.
• 23 – LINEAR_ACCELERATION is the change of DISTANCE_SPEED over time.
• 24 – ANGULAR_ACCELERATION is the change of ANGULAR_SPEED over time.
• 25 – TORQUE_SPEED is the change of torque over time.
• 26 – TORQUE_ACCELERATION is change of TORQUE_SPEED over time.
• 27 – TORQUE_PER_ANGLE_GRADIENT is the change of torque over angle.
• 28 – TORQUE_PER_ANGLE_GRADIENT2 is the change of TORQUE_PER_ANGLE_GRADIENT over angle. Example: It is used for yield and snug detection. It represents change of the slope in a torque over angle graph.

0:EngineeringUnits defines the engineering unit of the values.

Note: The quantity and units of the value is of importance, and it is going to be defined in harmonized way.

Note on Physical Quantity and Engineering Units

JoiningDataVariableType describes a minimal way to provide the PhysicalQuantity and EngineeringUnits properties for a given value.

An application can ensure that those are available by using a corresponding Conformance Unit defined for this use case.

If an application does not provide the EngineeringUnits for a given value, it is assumed to be in International System of Units (SI).