7 OPC UA ObjectTypes

7.1 FeederModuleType Definition

7.1.1 Overview

The FeederModuleType defines the structure of an Object of the FeederModuleType. Figure 13 shows the hierarchical structure and details of the composition. It is formally defined in Table 11.

An Object of the FeederModuleType represents a feeder system. A feeder system is a subdevice of an automatic scale for conveying the product (e.g., a belt or a screw conveyor) to or from the WeighingBridge. A feeder must be part of another device (e.g., an Object of the ScaleDeviceType).

The Type defines a general communication interface for a feeder system. It contains only variables and methods.

7.1.2 ObjectType Definition

The components of the FeederModuleType have additional references which are defined in Table 12.

7.1.3 ObjectType Description

FeederLoad defines the current loaded weight on the feeder system.

FeederRunning indicates that the feeder system is running.

FeederSpeed defines the current speed of a feeder system. The unit of the FeederSpeed depends on the construction system. Possible values are velocity or a flow rate (kg/s).

MaximumFeederSpeed defines the maximum possible speed of the feeder.

MinimalFeederSpeed defines the minimal possible speed of the feeder.

The Identification-AddIn contains information about the identification and nameplate of a feeder.

MachineryItemState is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryOperationMode is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryBuildingBlocks is used as described in OPC 40001-1.

7.1.4 Method SetFeederSpeed

Allows to set a new value for the speed of the feeder system. The OPC UA server must check if the value is between the minimal and maximum allowed speed and if the unit is allowed. The signature of this Method is specified below. Table 13 and Table 14 specify the Arguments and AddressSpace representation, respectively.

Signature

	SetFeederSpeed(
	[in]	Float		FeederSpeed
	[in]	EUInformation		EngineeringUnits);

7.2 PrinterModuleType Definition

7.2.1 Overview

The PrinterModuleType defines the structure of an Object of the PrinterModuleType. Figure 14 shows the hierarchical structure and details of the composition. It is formally defined in Table 15.

An Object of the PrinterModuleType represents a printing device. A printing device is a subdevice of a scale that prints labels or other documents related to the scale or to the measurement results. The variables of the module are only readable. So, the primary use case of the module is to monitor the label and print media status.

7.2.2 ObjectType Definition

The components of the ObjectType have additional subcomponents which are defined in Table 16

7.2.3 ObjectType Description

LabelLength defines the length of the labels in stock.

LabelStock indicates the level of labels in stock in percent.

LabelTypeId defines the Id of the label to be printed.

LabelWidth defines the width of the labels in stock.

PrintMediaStock defines the level of the print media in percent (e.g., ink, wear of thermal element, etc.).

The Identification-AddIn contains information about the identification and nameplate of a printer.

MachineryItemState is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryOperationMode is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryBuildingBlocks is used as described in OPC 40001-1.

7.3 ScaleSystemType Definition

7.3.1 Overview

The ScaleSystemType defines the structure of an Object of the ScaleSystemType. Figure 15 shows the hierarchical structure and details of the composition. It is formally defined in Table 17.

An Object of the ScaleSystemType represents a scale system and contains one or more scales. The ScaleSystemType defines a general communication interface for a scale system and is the entry point for clients. This interface makes it possible to interact with this system independent of the knowledge of the internal structure and the underlying processes of the scale system.

The system is modelled with a finite state machine and contains primary information about the state and the status of the system. It optionally can also contain the objects ProductionPreset and ProductionOutput.

7.3.2 ObjectType Definition

7.3.3 ObjectType Description

The Identification-AddIn contains information about the identification and nameplate of a machine.

A scale system can contain one or more scales. The scales must be a subtype of the ScaleDeviceType but must not be of the same type. The ScaleDeviceType is described in section 7.4.

Policy defines the legal guidelines that apply for the scale or need to be complied by the scale.

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 7.7 for the complete definition of the ProductionPresetType.

SystemState provides information about the current state of the scale system and methods for controlling it. PackMLBaseStateMachineType is defined in OPC 30050.

ProductionOutput defines the overall statistic for the scale production.

The modules (subdevices) of a scale system are aggregated in the SubDevices Object (see section 6.3 and OPC 10000-100).

MachineryItemState is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryOperationMode is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryBuildingBlocks is used as described in OPC 40001-1.

The components of the ScaleSystemType have additional references which are defined in Table 19.

7.3.4 Method ResetGlobalStatistics

All statistics relating to the scale system but not to a product are reset.

Signature

	ResetGlobalStatistics(
	);

7.4 ScaleDeviceType Definition

7.4.1 Overview

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 20.

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.

7.4.2 ObjectType Definition

The components of the ScaleDeviceType have additional references which are defined in Table 21.

7.4.3 ObjectType Description

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.

ProductionOutput defines the statistic for the scale prodution related to this ScaleDeviceType instance.

ProductionPreset contains the production presets. See section 7.7 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.

MachineryItemState is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryOperationMode is used as defined in OPC 40001-1. Shall also be referenced as AddIn in the MachineryBuildingBlocks Folder

MachineryBuildingBlocks is used as described in OPC 40001-1.

The components of the ScaleDeviceType have additional subcomponents which are defined in Table 22.

7.4.4 Method ClearTare

The tare value is set to zero or deleted.

Signature

	ClearTare(
	);

7.4.5 Method RegisterWeight

Triggers the registration of a measured value and a new value for the RegisteredWeight will be calculated.

Signature

	RegisterWeight(
	);

7.4.6 Method SetPresetTare

The method set the current PresetTare.

Signature

	SetPresetTare(
	[in]	Double		PresetTare
	[in]	EUInformation		EngineeringUnits);

7.4.7 Method SetZero

The method sets zero point. It uses the gross value of the CurrentWeight value.

Signature

	SetZero (
	);

7.4.8 Method SetTare

The method triggers the tare operation. The CurrentWeight value is used as the tare.

Signature

	SetTare(
	);

7.5 WeighingRangeElementType Definition

7.5.1 Overview

The WeighingRangeElementType defines the structure of an Object of WeighingRangeElementType. Figure 17 shows the hierarchical structure and details of the composition. It is formally defined in Table 25.

7.5.2 ObjectType Definition

7.5.3 ObjectType Description

ActualScaleInterval defines the difference between two consecutive indicated values.

Range defines the range within the scale that may be operated depending on the additional parameters within this type.

Range.EngineeringUnit defines the engineering unit of the range.

VerificationScaleInterval defines the value, expressed in units of mass, used for the classification and verification of an instrument.

The components of the WeighingRangeElementType have additional references which are defined in Table 26

7.6 StatisticType Definition

7.6.1 Overview

The StatisticType defines the structure of an Object of StatisticType. Figure 18 shows the hierarchical structure and details of the composition. It is formally defined in Table 27.

The StatisticType is a container for the different statistic values. All variables are optional so that the statistics can be instantiated in an application-specific way. The StatisticType can be instantiated with parent nodes (e.g., ScaleDeviceType, …). Parent nodes other than those described in this Companion Specification are possible.

7.6.2 ObjectType Definition

7.6.3 ObjectType Description

StartTime defines the point in time at which the system starts acquiring the statistic (e.g., 15:00). This value is relevant for time statistics. For example, it can be used to create statistics for the last 3 hours.

ResetCondition is a vendor-specific, human readable string that describes the reason and context for the reset of the statistics. For example, after 4 hours or after 1000 items. Please note that the subtype FloatingStatisticType is used for floating statistics.

	Examples:
	ResetCondition::= “AFTER 4 HOURS”
	ResetCondition::= “AFTER 1000 ITEMS”
	ResetCondition::= “OPERATOR”

Tare defines the last occurring tare value of the period of time which is used for the statistic.

Throughput defines the number of items registered over the period of the statistic (e.g., packages/min).

TotalPackages defines the totalized number of packages of one cell for weight determination. Contains packages that were sorted out but were physically transported via the scale. This value may be calculated by TotalPackagesAccepted + TotalPackagesRejected.

TotalPackagesWeighed defines the totalized number of packages for which a weight was measured. No reference to acceptance or rejection of the package.

LastItem contains the values of the last item.

7.7 ProductionPresetType Definition

7.7.1 Overview

The ProductionPresetType defines the structure of an Object of ProductionPresetType. Figure 19 shows the hierarchical structure and details of the composition. It is formally defined in Table 28.

ProductionPresetType provides methods to manage the production preset.

7.7.2 ObjectType Definition

7.7.3 ObjectType Description

CurrentProducts is an array containing the Ids of all product objects currently in processing mode. The product process can be started using the SelectProduct method or another interface or an external trigger signal.

Products contains the products used in the scale aggregated in the Products Object. The objects in the folder should have the type ProductType or a subtype of it. The subcomponents of the Products Object are defined in Table 29.

7.7.4 Method AddProduct

The method creates an Object with a subtype of ProductType from the address space. The Object needs a reference of the type "0:HasComponent" to the product folder of the scale device. The signature of this Method is specified below. Table 30 and Table 31 specify the Arguments and AddressSpace representation, respectively.

Note: To simplify the handling, it is recommended that during the creation of the product the object is immediately locked for the client. (see section 7.8)

Signature

	AddProduct(
	[in]	String		ProductName
	[in]	String		ProductId
	[in]	NodeId		ProductType
	[out]	NodeId		ProductNodeId
	);

7.7.5 Method SelectProduct

Selects the product. The scale is now able to process the product. This includes that the ID is saved in the CurrentProducts array and that the ProductMode switches from "Not processing" to "Processing". Table 32 and Table 33 specify the Arguments and AddressSpace representation, respectively.

Signature

	SelectProduct (
		[in]	String		ProductId
	);

7.7.6 Method DeselectProduct

Deselects the product. The scale should stop to process the product. This includes that the ID is removed in the CurrentProducts array and that the ProductMode switches from "Processing" to "Not processing". The signature of this Method is specified below. Table 34 and Table 35 specify the Arguments and AddressSpace representation, respectively.

Signature

	DeselectProduct (
		[in]	String		ProductId
	);

7.7.7 Method RemoveProduct

The method removes an Object from the address space with a subtype of the ProductType. The signature of this Method is specified below. Table 36 and Table 37 specify the Arguments and AddressSpace representation, respectively.

Signature

	RemoveProduct (
		[in]	String		ProductId
	);

7.7.8 Method SwitchProduct

Selects the new product and deselects the old product. The scale is now able to process the new product. This includes that the new ID is saved in the CurrentProducts array and that the ProductMode switches from "Not processing" to "Processing". Additionally, the old ID is removed in the CurrentProducts array and the ProductMode of the old product switches from "Processing" to "Not Processing". This method is only possible if only one product is used. The signature of this Method is specified below. Table 38 and Table 39 specify the Arguments and AddressSpace representation, respectively.

Signature

	SwitchProduct (
		[in]	String		ProductId
	);

7.8 ProductType Definition

7.8.1 Overview

The ProductType is an abstract type that defines the basic structure of all objects that represent a product. Figure 20 shows the hierarchical structure and details of the composition. It is formally defined in Table 40. An Object of the type ProductType represents a product related to the scale.

The different subtypes of the ProductType are described in the following sections. The ProductType only contains the basic information about a product. The scale type-specific information is modeled in the subtypes for the different scale types. The Create Method makes it possible that a vendor can add own Variables and extend the Create Method.

7.8.2 ObjectType Definition

7.8.3 ObjectType Description

BatchId is the ID of the batch to which this product belongs.

BatchName is the human-readable name of the batch to which this product belongs.

JobId is the ID of the job to which this product belongs.

JobName is the human-readable name of the job to which this product belongs.

PresetTare defines the predefined tare weight. The value must be written before the item is measured.

ProductId defines a unique ID of this product.

The ProductMode displays the current mode of the product. The ProductType instance can be in the mode "Processing" or "Not Processing". The mode is independent from the Lock. Thus, it is possible that a product is in the "Processing mode" and writeable. The combination of these both modes should be used with care as the writeable element may be in an inconsistent state. If the ProductMode is true the Object is in "Processing". Otherwise, it is in the mode "Not Processing".

ProductName defines the name of this product.

Lock is used as container for the LockingServicesType Methods and Properties. It is defined in OPC 10000-100 (Locking). In addition to this definition, the server can also lock an object of the ProductType. In this case the property LockingClient contains the ProductUri of the server and LockingUser contains an empty String.

NOTE: If an Object is writeable not all variables must be writeable. There can be additional restrictions based on the implementation.

Statistic contains the different statistic values of the product. The statistic can’t be reset manually. All measurements that relate to the product of the job will be used in the statistics.

The components of the ProductType have additional Attributes defined in Table 41.

7.9 AutomaticFillingScaleType Definition

7.9.1 Overview

The AutomaticFillingScaleType defines the structure of an Object of the AutomaticFillingScaleType. Figure 21 shows the hierarchical structure and details of the composition. It is formally defined in Table 42.

An Object of AutomaticFillingScaleType represents an automatic filling scale. It defines additional Methods and Properties required for managing automatic filling scales.

7.9.2 ObjectType Definition

7.9.3 ObjectType Description

Deviation defines the relative amount of over (positive value) or under (negative value) dosed value in relation to the TargetWeight.

ToleranceState describes the state of the tolerance deviation. Under: underneath the lower tolerance value. Over: above the upper tolerance value. In: within the tolerance values. The options “under” and “over” need to be determined via the TargetItemType information of TargetWeight.

ProductionPreset, which is inherited from ScaleDeviceType shall have instances of AutomaticFillingProductType or a subtype in the Products folder.

7.10 AutomaticFillingProductType Definition

7.10.1 Overview

The AutomaticFillingProductType defines the structure of an Object of the AutomaticFillingProductType. Figure 22 shows the hierarchical structure and details of the composition. It is formally defined in Table 43.

An Object of AutomaticFillingProductType represents a product of an automatic filling scale. It defines additional methods and properties required for managing the product.

7.10.2 ObjectType Definition

7.10.3 ObjectType Description

FeedRateMeasuringInterval defines the measuring interval for evaluating the current flowrate.

FillingTime defines the maximum duration for the filling process to take place. Needs to be completed during this period.

FineFeedWeight defines the volume to be dosed in fine flow.

InFlightWeight defines the volume that is behind the valve/in flight after feeding is stopped.

JogFeed defines if an additional dosage is necessary.

MinimumDeltaPerFeedRateMeasuringInterval defines the minimum amount of weight data which needs to change within the FeedRateMeasuringInterval. Otherwise, the filling procedure is not valid.

SettlingTime defines the time that needs to be passed before the measurement process can be triggered.

TareId defines an ID of tare value for the current product or item.

TargetWeight defines the preset of the volume to be processed.

7.11 CatchweigherType Definition

7.11.1 Overview

The CatchweigherType defines the structure of an Object of the CatchweigherType. Figure 23 shows the hierarchical structure and details of the composition. It is formally defined in Table 44.

An Object of the CatchweigherType represents a catchweigher. It has no method or properties defined. The CheckweigherType and the AutomaticWeightPriceLablerType inherit from the CatchweigherType.

7.11.2 ObjectType Definition

7.11.3 ObjectType Description

ProductionPreset, which is inherited from ScaleDeviceType shall have instances of CatchweigherProductType or a subtype in the Products folder.

7.12 CatchweigherProductType Definition

7.12.1 Overview

The CatchweigherProductType defines the structure of an Object of the CatchweigherProductType. Figure 24 shows the hierarchical structure and details of the composition. It is formally defined in Table 45.

An Object of the CatchweigherProductType represents a product of a catchweigher. It defines additional methods and properties required for managing the product.

7.12.2 ObjectType Definition