The ScaleDeviceType defines the structure of an Object of the ScaleDeviceType. Figure 16 shows the hierarchical structure and details of the composition. It is formally defined in Table 17.
The ScaleDeviceType is an abstract ObjectType. An Object of a subtype of the ScaleDeviceType represents a scale. The ScaleDeviceType contains all information that is relevant for most of the scale types. The system is modeled with a finite state machine and contains primary information about the state and the status of the system.
Figure 16 − Overview ScaleDeviceType
Table 17 − ScaleDeviceType Definition
|
Attribute |
Value |
||||
|
BrowseName |
ScaleDeviceType |
||||
|
IsAbstract |
True |
||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
|
Subtype of the ComponentType defined in OPC 10000-100 |
|||||
|
0:HasProperty |
Variable |
AllowedEngineeringUnits |
0:EUInformation[] |
0:PropertyType |
Optional |
|
0:HasComponent |
Method |
ClearTare |
|
|
Optional |
|
0:HasComponent |
Variable |
CurrentWeight |
WeightType |
WeightItemType |
Mandatory |
|
0:HasComponent |
Object |
ListOfWeighingRanges |
|
WeighingRangeElementType |
MandatoryPlaceholder |
|
0:HasProperty |
Variable |
MaterialClass |
0:LocalizedText |
0:PropertyType |
Optional |
|
0:HasComponent |
Variable |
MinimalWeight |
0:Number |
0:AnalogUnitType |
Optional |
|
0:HasProperty |
Variable |
ProcessStateId |
0:String |
0:PropertyType |
Optional |
|
0:HasProperty |
Variable |
ProcessStateMessage |
0:LocalizedText |
0:PropertyType |
Optional |
|
0:HasComponent |
Object |
ProductionPreset |
|
ProductionPresetType |
Optional |
|
0:HasProperty |
Variable |
Policy |
0:LocalizedText[] |
0:PropertyType |
Optional |
|
0:HasComponent |
Variable |
RegisteredWeight |
WeightType |
WeightItemType |
Optional |
|
0:HasComponent |
Method |
RegisterWeight |
|
|
Optional |
|
0:HasComponent |
Method |
SetPresetTare |
|
|
Optional |
|
0:HasComponent |
Method |
SetTare |
|
|
Optional |
|
0:HasComponent |
Method |
SetZero |
|
|
Optional |
|
0:HasComponent |
Object |
SubDevices |
|
2:ConfigurableObjectType |
Optional |
|
0:HasComponent |
Object |
State |
|
4:PackMLBaseStateMachineType |
Optional |
|
|
|||||
|
The following nodes are overridden from ComponentType and the Modelling Rule change to Mandatory |
|||||
|
0:HasProperty |
Variable |
2:DeviceClass |
|
0:PropertyType |
Mandatory |
|
0:HasProperty |
Variable |
2:HardwareRevision |
|
0:PropertyType |
Mandatory |
|
0:HasProperty |
Variable |
2:Manufacturer |
|
0:PropertyType |
Mandatory |
|
0:HasProperty |
Variable |
2:Model |
|
0:PropertyType |
Mandatory |
|
0:HasProperty |
Variable |
2:SerialNumber |
|
0:PropertyType |
Mandatory |
|
0:HasProperty |
Variable |
2:SoftwareRevision |
|
0:PropertyType |
Mandatory |
|
|
|
|
|
|
|
|
The following nodes are overridden from ComponentType, the Modelling Rule change to Mandatory and the new ObjectType is now MachineIdentificationType |
|||||
|
0:HasAddIn |
Object |
2:Identification |
|
3:MachineIdentificationType |
Optional |
AllowedEngineeringUnits contains an array of engineering units that can be handled by the OPC UA server. A server that supports a method with the input argument EUInformation must also provide this array.
CurrentWeight defines the current value that is measured at the sensor at the current timestamp. This might be a highly fluctuating value.
MaterialClass defines the allowed material the scale may measure. It is only relevant for certain scales (e.g., totalizing hopper scale or continuous scale).
The MinimalWeight is the smallest sample quantity required for a weighment to just achieve a specified relative accuracy of weighing (see also EURAMET Calibration Guide No. 18). So it is the smallest load or component of a recipe that may be weighed on the scale. SubDevices: the modules (subdevices) of a modular scale are aggregated in the SubDevices Object. See OPC Unified Architecture for Devices for more information.
ProcessStateId contains a relating identification for the occurring ProcessStateMessage.
ProcessStateMessage contains the message of the current overall state of the scale.
ProductionPreset contains the production presets. See section 8.7 for the complete definition of the ProductionPresetType.
RegisteredWeight defines the last valid measurement that was recorded and will be used for further processing.
ListOfWeighingRanges defines the weighing range and resolution the scale may operate in with a structure of range and resolution.
Policy defines the legal guidelines that apply for the scale or need to be complied by the scale.
ScaleStateMachine provides information about the current state of the scale system and methods for controlling it. PackMLBaseStateMachineType is defined in OPC 30050.
The components of the ScaleDeviceType have additional references which are defined in Table 18.
Table 18 – ScaleDeviceType Additional Subcomponents
|
BrowsePath |
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Others |
|
SubDevices |
0:HasComponent |
Object |
<FeederModule> |
|
FeederModuleType |
OptionalPlaceholder |
|
SubDevices |
0:HasComponent |
Object |
<PrinterModule> |
|
PrinterModuleType |
OptionalPlaceholder |
|
SubDevices |
0:HasComponent |
Object |
<WeighingModule> |
|
WeighingModuleType |
OptionalPlaceholder |
The tare value is set to zero or deleted.
Signature
ClearTare(
);
Triggers the registration of a measured value and a new value for the RegisteredWeight will be calculated.
Signature
RegisterWeight(
);
The method set the current PresetTare.
Signature
SetPresetTare(
[in]Double PresetTare
[in]EUInformation EngineeringUnits);
Table 19 – SetPresetTare Method Arguments
|
Argument |
Description |
|
PresetTare |
The value which should be set as tare value. |
|
EngineeringUnits |
The unit of the preset. The server must check the unit. |
Table 20 – SetPresetTare Method AddressSpace definition
|
Attribute |
Value |
||||
|
BrowseName |
SetPresetTare |
||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
|
0:HasProperty |
Variable |
InputArguments |
Argument[] |
0:PropertyType |
Mandatory |
The method sets zero point. It uses the gross value of the CurrentWeight value.
Signature
SetZero (
);
The method triggers the tare operation. The CurrentWeight value is used as the tare.
Signature
SetTare(
);