1 Scope

This OPC UA Companion Specification shall define the required data structures, parameters, methods, state machines etc. for the communication among process air extraction and filtration systems (PAEFS), between process air extraction and filtration systems and preceding machinery, between process air extraction and filtration systems and supporting systems (e.g. technical ventilation, conveying systems) and from process air extraction and filtration systems into higher level manufacturing systems (e.g. Manufacturing Execution System, MES), for information and diagnostic purposes and to set parameters regarding the extraction and filtration system process.

Note: Compressed air is not considered in this Companion Specification.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments and errata) applies.

OPC 10000-1, OPC Unified Architecture - Part 1: Overview and Concepts

OPC 10000-1

OPC 10000-2, OPC Unified Architecture - Part 2: Security Model

OPC 10000-2

OPC 10000-3, OPC Unified Architecture - Part 3: Address Space Model

OPC 10000-3

OPC 10000-4, OPC Unified Architecture - Part 4: Services

OPC 10000-4

OPC 10000-5, OPC Unified Architecture - Part 5: Information Model

OPC 10000-5

OPC 10000-6, OPC Unified Architecture - Part 6: Mappings

OPC 10000-6

OPC 10000-7, OPC Unified Architecture - Part 7: Profiles

OPC 10000-7

OPC 10000-8, OPC Unified Architecture - Part 8: Data Access

OPC 10000-8

OPC 10000-9, OPC Unified Architecture - Part 9: Alarms and Conditions

OPC 10000-9

OPC 10000-16, OPC Unified Architecture - Part 16: State Machines

OPC 10000-16

OPC 10000-100, OPC Unified Architecture - Part 100: Devices

OPC 10000-100

OPC 30081, OPC UA for Process Automation Devices – PA-DIM^TM 

http://www.opcfoundation.org/UA/PADIM/ 

OPC 40001-1, OPC UA for Machinery - Part 1: Basic Building Blocks

http://www.opcfoundation.org/UA/Machinery/

OPC 40001-2, OPC UA for Machinery - Part 2: Process Values

http://www.opcfoundation.org/UA/Machinery/ProcessValues/

3 Terms, definitions and conventions

3.1 Overview

It is assumed that basic concepts of OPC UA information modelling are understood in this specification. This specification will use these concepts to describe the Process Air Extraction and Filtration Systems Information Model. For the purposes of this document, the terms and definitions given in OPC 10000-1, OPC 10000-3, OPC 10000-4, OPC 10000-5, OPC 10000-7, OPC 10000-100, OPC 40001-1, OPC 40001-2.

Note that OPC UA terms and terms defined in this specification are italicized in the specification.

3.2 OPC UA for Process Air Extraction and Filtration Systems terms

3.2.1 Filter system

System which serves the purpose of extracting and filtering process gas; e.g., air. It consists of several filter units and other devices and components.

3.2.2 Filter unit

Subcomponent of a filter system, consisting of other devices and components.

3.2.3 Separator

Part of the filter unit that filters solid, liquid or gaseous components from the process gas.
Examples are:

Wet separator

Cartridge filter

Automatic roll band filter

Electrostatic precipitator

3.2.4 Process air

Atmospheric air that comes into contact with a manufacturing process and must be present in a defined degree of purity for the manufacturing process to function or is contaminated with released substances (e.g. solid, liquid or gaseous components) or energy loads as a result of the manufacturing process

3.2.5 Air connection

Air interface that connects the filter system and the filter units to the process air duct system. Parts of this interface can be, for example, gate valves or check valves.

3.2.6 Discharge system

Device used to remove collected filter material from the filter unit. Examples are: rotary valves or discharge gate valves.

3.2.7 Cleaning unit

Device for the reduction of filtered materials in separators. The cleaning can be achieved e.g. by vibration, reversed airflow or compressed-air blast (EN 12779:2015).

3.2.8 Device for filter aid

Device for the application of a filter aid. Examples of filter aids are: finely divided, porous solid material, material for neutralization of gases or liquids.

3.2.9 Fan

Component within the filter system which produces the volume flow rate necessary for extracting process gas. Examples are: ventilators, blowers

3.2.10 Temperature regulator

Component in the filter system for heating or cooling the process gas.

3.2.11 Safety system

Component that represents a protective device. Examples are: extinguishing systems, smoke detectors, spark detectors.

3.3 Abbreviated terms

PAEFS Process Air Extraction and Filtration Systems

ESP Electrostatic precipitator

3.4 Conventions used in this document

3.4.1 Conventions for Node descriptions

3.4.1.1 Node definitions

Node definitions are specified using tables (see Table 2).

Attributes are defined by providing the Attribute name and a value, or a description of the value.

References are defined by providing the ReferenceType name, the BrowseName of the TargetNode and its NodeClass.

If the TargetNode is a component of the Node being defined in the table the Attributes of the composed Node are defined in the same row of the table.

The DataType is only specified for Variables; “[<number>]” indicates a single-dimensional array, for multi-dimensional arrays the expression is repeated for each dimension (e.g. [2][3] for a two-dimensional array). For all arrays the ArrayDimensions is set as identified by <number> values. If no <number> is set, the corresponding dimension is set to 0, indicating an unknown size. If no number is provided at all the ArrayDimensions can be omitted. If no brackets are provided, it identifies a scalar DataType and the ValueRank is set to the corresponding value (see OPC 10000-3). In addition, ArrayDimensions is set to null or is omitted. If it can be Any or ScalarOrOneDimension, the value is put into “{<value>}”, so either “{Any}” or “{ScalarOrOneDimension}” and the ValueRank is set to the corresponding value (see OPC 10000-3) and the ArrayDimensions is set to null or is omitted. Examples are given in Table 1.

The TypeDefinition is specified for Objects and Variables.

The TypeDefinition column specifies a symbolic name for a NodeId, i.e. the specified Node points with a HasTypeDefinition Reference to the corresponding Node.

The ModellingRule of the referenced component is provided by specifying the symbolic name of the rule in the ModellingRule column. In the AddressSpace, the Node shall use a HasModellingRule Reference to point to the corresponding ModellingRule Object.

If the NodeId of a DataType is provided, the symbolic name of the Node representing the DataType shall be used.

Note that if a symbolic name of a different namespace is used, it is prefixed by the NamespaceIndex (see 3.4.2.2).

Nodes of all other NodeClasses cannot be defined in the same table; therefore only the used ReferenceType, their NodeClass and their BrowseName are specified. A reference to another part of this document points to their definition. Table 2 illustrates the table. If no components are provided, the DataType, TypeDefinition and ModellingRule columns may be omitted and only a Comment column is introduced to point to the Node definition.

Each Type Node or well-known Instance Node defined shall have one or more ConformanceUnits defined in 11.1 that require the Node to be in the AddressSpace.

The relations between Nodes and ConformanceUnits are defined at the end of the tables defining Nodes, one row per ConformanceUnit. The ConformanceUnits are reflected in the Category element for the Node definition in the UANodeSet (see OPC 10000-6).

The list of ConformanceUnits in the UANodeSet allows Servers to optimize resource consumption by using a list of supported ConformanceUnits to select a subset of the Nodes in an Information Model.

When a Node is selected in this way, all dependencies implied by the References are also selected.

Dependencies exist if the Node is the source of HasTypeDefinition, HasInterface, HasAddIn or any HierarchicalReference. Dependencies also exist if the Node is the target of a HasSubtype Reference. For Variables and VariableTypes, the value of the DataType Attribute is a dependency. For DataType Nodes, any DataTypes referenced in the DataTypeDefinition Attribute are also dependencies.

For additional details see OPC 10000-5.

Components of Nodes can be complex that is containing components by themselves. The TypeDefinition, NodeClass and DataType can be derived from the type definitions, and the symbolic name can be created as defined in 3.4.3.1. Therefore, those containing components are not explicitly specified; they are implicitly specified by the type definitions.

The Other column defines additional characteristics of the Node. Examples of characteristics that can appear in this column are show in Table 3.

If multiple characteristics are defined they are separated by commas. The name or the short name may be used.

3.4.1.2 Additional References

To provide information about additional References, the format as shown in Table 4 is used.

The components of the ObjectType have additional references which are defined in Table 4.

References can be to any other Node.

3.4.1.3 Additional sub-components

To provide information about sub-components, the format as shown in Table 5 is used.

3.4.1.4 Additional Attribute values

The type definition table provides columns to specify the values for required Node Attributes for InstanceDeclarations. To provide information about additional Attributes, the format as shown in Table 6 is used.

There can be multiple columns to define more than one Attribute.

3.4.2 NodeIds and BrowseNames

3.4.2.1 NodeIds

The NodeIds of all Nodes described in this standard are only symbolic names. Annex A defines the actual NodeIds.

The symbolic name of each Node defined in this document is its BrowseName, or, when it is part of another Node, the BrowseName of the other Node, a “.”, and the BrowseName of itself. In this case “part of” means that the whole has a HasProperty or HasComponent Reference to its part. Since all Nodes not being part of another Node have a unique name in this document, the symbolic name is unique.

The NamespaceUri for all NodeIds defined in this document is defined in Annex A. The NamespaceIndex for this NamespaceUri is vendor-specific and depends on the position of the NamespaceUri in the server namespace table.

Note that this document not only defines concrete Nodes, but also requires that some Nodes shall be generated, for example one for each Session running on the Server. The NodeIds of those Nodes are Server-specific, including the namespace. But the NamespaceIndex of those Nodes cannot be the NamespaceIndex used for the Nodes defined in this document, because they are not defined by this document but generated by the Server.

3.4.2.2 BrowseNames

The text part of the BrowseNames for all Nodes defined in this document is specified in the tables defining the Nodes. The NamespaceUri for all BrowseNames defined in this document is defined in 12.2.

For InstanceDeclarations of NodeClass Object and Variable that are placeholders (OptionalPlaceholder and MandatoryPlaceholder ModellingRule), the BrowseName and the DisplayName are enclosed in angle brackets (<>) as recommended in OPC 10000-3. If the BrowseName is not defined by this document, a namespace index prefix is added to the BrowseName (e.g., prefix '0' leading to ‘0:EngineeringUnits’ or prefix '2' leading to ‘2:DeviceRevision’). This is typically necessary if a Property of another specification is overwritten or used in the OPC UA types defined in this document. Table 121 provides a list of namespaces and their indexes as used in this document.

3.4.3 Common Attributes

3.4.3.1 General

The Attributes of Nodes, their DataTypes and descriptions are defined in OPC 10000-3. Attributes not marked as optional are mandatory and shall be provided by a Server. The following tables define if the Attribute value is defined by this specification or if it is server-specific.

For all Nodes specified in this specification, the Attributes named in Table 7 shall be set as specified in the table.

3.4.3.2 Objects

For all Objects specified in this specification, the Attributes named in Table 8 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.

3.4.3.3 Variables

For all Variables specified in this specification, the Attributes named in Table 9 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.

3.4.3.4 VariableTypes

For all VariableTypes specified in this specification, the Attributes named in Table 10 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.

3.4.3.5 Methods

For all Methods specified in this specification, the Attributes named in Table 11 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.

4 General information to Process Air Extraction and Filtration Systems and OPC UA

4.1 Introduction to Process Air Extraction and Filtration Systems

The joint VDMA and OPC Foundation “Process Air Extraction and Filtration Systems” OPC UA Working Group has developed an OPC UA Information Model for Process Air Extraction and Filtration Systems. Universal manufacturer-independent interfaces based on OPC UA have been created.

PAEFS are important systems which are used in the process industry and manufacturing industry or others. An elementary task of PAEFS in operational process air technology is to fulfill their basic function of supplying a process with the required air and/or establishing the air condition necessary for the operation of a process and/or eliminating substances released by the process (e.g. extraction systems for hazardous substances).

Extraction and filtration systems include inertial force extraction and filtration systems, electrostatic extraction and filtration systems, wet separators and automatic roll filters. These extraction and filtration systems may be cleanable or non-cleanable as well as regenerative or non-regenerative.

Apart from the basic function, additional functionalities, such as:

self-monitoring

generation of condition information

diagnostic purposes to set parameters regarding the extraction and filtration system process

identification of PAEFS for device management

energy consumption for energy management applications

remote device control

are essential for data generation, for the optimization of performance, (foresighted) maintenance and operational process control.

4.2 Introduction to OPC Unified Architecture

4.2.1 What is OPC UA?

OPC UA is an open and royalty free set of standards designed as a universal communication protocol. While there are numerous communication solutions available, OPC UA has key advantages:

A state of art security model (see OPC 10000-2).

A fault tolerant communication protocol.

An information modelling framework that allows application developers to represent their data in a way that makes sense to them.

OPC UA has a broad scope which delivers for economies of scale for application developers. This means that a larger number of high-quality applications at a reasonable cost are available. When combined with semantic models such as Process Air Extraction and Filtration Systems, OPC UA makes it easier for end users to access data via generic commercial applications.

The OPC UA model is scalable from small devices to ERP systems. OPC UA Servers process information locally and then provide that data in a consistent format to any application requesting data - ERP, MES, PMS, Maintenance Systems, HMI, Smartphone or a standard Browser, for examples. For a more complete overview see OPC 10000-1.

4.2.2 Basics of OPC UA

As an open standard, OPC UA is based on standard internet technologies, like TCP/IP, HTTP, Web Sockets.

As an extensible standard, OPC UA provides a set of Services (see OPC 10000-4) and a basic information model framework. This framework provides an easy manner for creating and exposing vendor defined information in a standard way. More importantly all OPC UA Clients are expected to be able to discover and use vendor-defined information. This means OPC UA users can benefit from the economies of scale that come with generic visualization and historian applications. This specification is an example of an OPC UA Information Model designed to meet the needs of developers and users.

OPC UA Clients can be any consumer of data from another device on the network to browser based thin clients and ERP systems. The full scope of OPC UA applications is shown in Figure 1.

OPC UA provides a robust and reliable communication infrastructure having mechanisms for handling lost messages, failover, heartbeat, etc. With its binary encoded data, it offers a high-performing data exchange solution. Security is built into OPC UA as security requirements become more and more important especially since environments are connected to the office network or the internet and attackers are starting to focus on automation systems.

4.2.3 Information modelling in OPC UA

4.2.3.1 Concepts

OPC UA provides a framework that can be used to represent complex information as Objects in an AddressSpace which can be accessed with standard services. These Objects consist of Nodes connected by References. Different classes of Nodes convey different semantics. For example, a Variable Node represents a value that can be read or written. The Variable Node has an associated DataType that can define the actual value, such as a string, float, structure etc. It can also describe the Variable value as a variant. A Method Node represents a function that can be called. Every Node has a number of Attributes including a unique identifier called a NodeId and non-localized name called as BrowseName. An Object representing a ‘Reservation’ is shown in Figure 2.

Object and Variable Nodes represent instances and they always reference a TypeDefinition (ObjectType or VariableType) Node which describes their semantics and structure. Figure 3 illustrates the relationship between an instance and its TypeDefinition.

The type Nodes are templates that define all of the children that can be present in an instance of the type. In the example in Figure 3 the PersonType ObjectType defines two children: First Name and Last Name. All instances of PersonType are expected to have the same children with the same BrowseNames. Within a type the BrowseNames uniquely identify the children. This means Client applications can be designed to search for children based on the BrowseNames from the type instead of NodeIds. This eliminates the need for manual reconfiguration of systems if a Client uses types that multiple Servers implement.

OPC UA also supports the concept of sub-typing. This allows a modeller to take an existing type and extend it. There are rules regarding sub-typing defined in OPC 10000-3, but in general they allow the extension of a given type or the restriction of a DataType. For example, the modeller may decide that the existing ObjectType in some cases needs an additional Variable. The modeller can create a subtype of the ObjectType and add the Variable. A Client that is expecting the parent type can treat the new type as if it was of the parent type. Regarding DataTypes, subtypes can only restrict. If a Variable is defined to have a numeric value, a sub type could restrict it to a float.

References allow Nodes to be connected in ways that describe their relationships. All References have a ReferenceType that specifies the semantics of the relationship. References can be hierarchical or non-hierarchical. Hierarchical references are used to create the structure of Objects and Variables. Non-hierarchical are used to create arbitrary associations. Applications can define their own ReferenceType by creating subtypes of an existing ReferenceType. Subtypes inherit the semantics of the parent but may add additional restrictions. Figure 4 depicts several References, connecting different Objects.

The figures above use a notation that was developed for the OPC UA specification. The notation is summarized in Figure 5. UML representations can also be used; however, the OPC UA notation is less ambiguous because there is a direct mapping from the elements in the figures to Nodes in the AddressSpace of an OPC UA Server.

A complete description of the different types of Nodes and References can be found in OPC 10000-3 and the base structure is described in OPC 10000-5.

OPC UA specification defines a very wide range of functionality in its basic information model. It is not required that all Clients or Servers support all functionality in the OPC UA specifications. OPC UA includes the concept of Profiles, which segment the functionality into testable certifiable units. This allows the definition of functional subsets (that are expected to be implemented) within a companion specification. The Profiles do not restrict functionality, but generate requirements for a minimum set of functionality (see OPC 10000-7)

4.2.3.2 Namespaces

OPC UA allows information from many different sources to be combined into a single coherent AddressSpace. Namespaces are used to make this possible by eliminating naming and id conflicts between information from different sources. Each namespace in OPC UA has a globally unique string called a NamespaceUri which identifies a naming authority and a locally unique integer called a NamespaceIndex, which is an index into the Server's table of NamespaceUris. The NamespaceIndex is unique only within the context of a Session between an OPC UA Client and an OPC UA Server- the NamespaceIndex can change between Sessions and still identify the same item even though the NamespaceUri's location in the table has changed. The Services defined for OPC UA use the NamespaceIndex to specify the Namespace for qualified values.

There are two types of structured values in OPC UA that are qualified with NamespaceIndexes: NodeIds and QualifiedNames. NodeIds are locally unique (and sometimes globally unique) identifiers for Nodes. The same globally unique NodeId can be used as the identifier in a node in many Servers – the node's instance data may vary but its semantic meaning is the same regardless of the Server it appears in. This means Clients can have built-in knowledge of of what the data means in these Nodes. OPC UA Information Models generally define globally unique NodeIds for the TypeDefinitions defined by the Information Model.

QualifiedNames are non-localized names qualified with a Namespace. They are used for the BrowseNames of Nodes and allow the same names to be used by different information models without conflict. TypeDefinitions are not allowed to have children with duplicate BrowseNames; however, instances do not have that restriction.

4.2.3.3 Companion Specifications

An OPC UA companion specification for an industry specific vertical market describes an Information Model by defining ObjectTypes, VariableTypes, DataTypes and ReferenceTypes that represent the concepts used in the vertical market, and potentially also well-defined Objects as entry points into the AddressSpace.

5 Use cases

Below is a list of possible use cases a PAEFS may implement fully or partly.

5.1 Device Identification

Device Identification forms the basis for the operation of a Process Air Extraction and Filtration System and the operator’s plant asset management. For this purpose, the PAEFS shall provide properties for asset identification. An operator/integrator should be able to explore the topology of the PAEFS. All browsable components shall be identifiable.

5.2 Device Monitoring

A PAEFS can be monitored by reading and collecting sensor and operational data. This data collection forms the basis for process planning and job management.

The data may include e.g., operating hours, material supply and energy consumption.

5.3 Device Maintenance

Maintenance management is designed to give the plant operator access to PAEFS-specific maintenance information. A plant operator can actively check the health status of the plant or be notified about problems and errors. This allows the operator to react to impending failures or to proactively plan maintenance.

5.4 Device Operation

Device Operation includes turning on and off the PAEFS or one of its components and choosing from different operating modes. Furthermore, setpoints can be configured and methods for controlling the PAEFS can be called.

5.5 Untitled

6 PAEFS Information Model overview

6.1 Model Overview

Figure 6 shows a schematic overview of all parts a PAEFS consists of and how they relate to each other. The representation uses a mixture of a type and instance representation for ease of understanding. Auxiliary objects that represent data structures are not displayed.

The filter system serves as a root node to which several filter units are attached. A filter unit consists of subcomponents, some of which are optional.

Some components can be shared between filter units and some components are exclusively used by one filter unit. A component which can be used by exactly one filter unit is represented as a child node of the filter unit. A component which is shared by multiple filter units is represented as a child node of the filter system and referenced by its filter units via the Uses reference defined in 10.1.

The shared component temperature regulator is intended to be referenced by one or more filter units. The same applies to the fan component. The discharge system, the cleaning unit and the device for filter aid may be shared by multiple separators. These components should be referenced from the separator by the Uses ReferenceType. Every component may have a safety system that is responsible for monitoring the component. The safety system is referenced by the component via a Uses reference.

Example: Two filter units share a fan. The fan can be used either by one filter unit or by the other filter unit. Both fans are referenced by a Uses reference from the filter unit.

The Uses reference is a many-to-many relation between components which are functionally connected. It serves primarily navigational and organizational purposes. 

The filter system and the filter unit must each have exactly two instances of the air connection. Any other component can be instantiated any number of times. The safety system can be used by any main component via the Uses reference. Main components are defined in 10.1.

For the benefit of clarity, the dashed arrows between the safety system and other components in Figure 6 are not drawn.

Depending on the design of the plant, either the filter system or the individual filter units can be regarded as a machine. The following cases are possible:

The filter system is a machine and the filter units are its components.

The filter system is not a machine and each filter unit is a machine.

Each machine has methods to turn it on and off. Each machine is listed in the machines folder provided by OPC 40001-1.

The air connection component is an abstract component. It represents a link between two air-carrying systems. It is not a physical component. There are always two air connections, one for the air intake and one for the air outlet. The two air connections are available both on the filter system (total air inflow/outflow) and on the individual filter units (total air distribution).

6.2 PAEFS modelling examples

6.2.1 Example 1: Air filtration system with redundant cartridge filter

This filter system has two identical filter units and two fans. Only one filter unit is in operation at a time. Both units have a common air inflow and outflow. The air flow can be routed through either of the filter units via switch-over flaps.

In this example, the ducting of the common air intake and outlet of the filter units is represented by the two air connections on the filter system. The total airflow is distributed to the two filter units via the switch flaps. The split airflow is represented by the two air connections on the filter units.

6.2.2 Example 2: Air filtration system with multiple separators

This filter system is used for the filtration of laser dust. It is modelled as a filter system with one filter unit. Physically, three different filter types are installed: a cartridge filter (CartridgeFilter1), a HEPA storage filter (CartridgeFilter2), and a sorption filter (CartridgeFilter3). In the PAEFS data model, all three filters are represented by the cartridge filter type. Assigned to CartridgeFilter1 are a device for adding filter aids to bind sticky and very fine laser smoke, and a cleaning unit for removing dust from the cartridge filter.

The assignment in the PAEFS data model is done via the Uses reference. The system also has several safety systems that are connected to the component to be monitored via a Uses reference.

6.2.3 Example 3: Electrostatic precipitator with three filter stages

This filter system is used for the filtration of plasticizers using electrostatic precipitators. The polluted intake air is drawn in by a fan (Fan 1). The polluted air is mixed with fresh air before it is directed to the precipitator. The fresh air is preheated by a heat exchanger and a heater (temperature regulator). A second fan (Fan 2) is used for this purpose. The actual separation is performed by three electrostatic precipitators, each with two high-voltage units. Each high-voltage unit has two collectors and two ionizers. Each electrostatic precipitator is considered as one stage of the filter unit.

7 OPC UA ObjectTypes

Figure 13 shows all ObjectTypes which are defined by this companion specification.

7.1 SensorMonitoringType ObjectType Definition

The SensorMonitoringType represents a process value whose value is determined by a measuring device. It is formally defined in Table 12. The measuring device can be identified via the MachineryComponentIdentificationType from OPC 40001-1.

The process value and all associated metadata such as unit and value ranges are inherited from the ProcessValueType. The optional setpoint of the ProcessValueType must not be used in instances of this type. If a setpoint is needed, the subtypes SensorSetpointReadType and SensorSetpointWrite should be used.

Optionally it can be specified whether the measuring signal is provided in analog or digital form.

The components of the SensorMonitoringType have additional references which are defined in Table 14.

7.2 SensorSetpointReadType ObjectType Definition

The SensorSetpointReadType represents a process value and provides a setpoint for this value. It is formally defined in Table 15. A device is not required to provide a setpoint.

This type provides only read-access to the setpoint. Write-access is provided by SensorSetpointWriteType.

The component Variables of the SensorSetpointReadType have additional Attributes defined in Table 16.

The components of the SensorSetpointReadType have additional subcomponents which are defined in Table 17.

Some devices may control a process value via alternative, mutually exclusive setpoint (e.g. a target value for either pressure or airflow may be specified). The IsActiveSetpoint variable indicates whether the setpoint of an instance of this type is the currently active setpoint.

7.3 SensorSetpointWriteType ObjectType Definition

The SensorSetpointWriteType represents a process value and provides a readable and writable setpoint for this value. It is formally defined in Table 18.

The components of the SensorSetpointWriteType have additional subcomponents which are defined in Table 19.

7.4 ConsumptionType ObjectType Definition

The ConsumptionType contains information related to the consumption of a device and is formally defined in Table 20. Consumption can refer, for example, to electricity or compressed air consumption.

7.5 FilterSystemType ObjectType Definition

7.5.1 Overview

The FilterSystemType serves the purpose of extracting and filtering process gas, e.g., air. It consists of several filter units and other devices and components. It is formally defined in Table 22.

The server sends a MalfunctionAlarmType event when the Malfunction property changes.

The MaintenanceRequestedConditionType is triggered when the MaintenanceRequested property changes.

The components of the FilterSystemType have additional subcomponents which are defined in Table 24.

The components of the FilterSystemType have additional references which are defined in Table 25.

7.5.2 OperationOn Method

The Method OperationOn turns the filter system machine on. It should only be available on the filter system if the filter units are considered components of the filter system and do not have their own OperationOn and OperationOff methods. The method changes the state of MachineryItemState. The signature of this Method is specified below. Table 26 specifies the AddressSpace representation.

Signature

	OperationOn ()

7.5.3 OperationOff Method

The Method OperationOff turns the filter system machine off. As with the OperationOn method, this method should be present under the FilterSystemType if and only if the filter units are considered components of the system rather than individual machines. The method changes the state of MachineryItemState. The signature of this Method is specified below. Table 27 specifies the AddressSpace representation.

Signature

	OperationOff ()

7.5.4 MachineryItemState StateMachine

This building block provides information about the state of a MachineryItem. It defines the states NotAvailable, OutOfService, NotExecuting and Executing. The exact semantics of the states are defined in OPC 40001-1. The StateMachine defines Transitions between all States. Instances might restrict the usage of the defined States and Transitions. An overview of the StateMachine is provided in Figure 15.

7.6 FilterUnitType ObjectType Definition

7.6.1 Overview

The FilterUnitType is a subcomponent of a filter system consisting of other devices and components.

It is formally defined in Table 28.

The server sends a MalfunctionAlarmType event when the Malfunction property changes.

The MaintenanceRequestedConditionType is triggered when the MaintenanceRequested property changes.

The amount of gas that is processed by the filter unit can be governed either by airflow, pressure, or rotational fan speed. Only one of these three quantities can be specified as the setpoint at a time.

The methods SetAndActivateAirflowSetpoint, SetAndActivatePressureSetpoint, and SetAndActivateRotationalSpeedSetpoint set the value of the setpoint and set this setpoint as the active setpoint.

Each of the objects Airflow, Pressure, and RotationalSpeed of type SensorType contains a read-only boolean variable IsActiveSetpoint. The boolean IsActiveSetpoint indicates which of the three setpoints is currently active. IsActiveSetpoint must be true for exactly one quantity at any given time.

The components of the FilterUnitType have additional references which are defined in Table 31.

7.6.2 SetAndActivateAirflowSetpointMethod

The Method SetAndActivateAirflowSetpoint sets a setpoint for the airflow. The value’s unit is the same as the one specified in object Airflow. Since setpoints are mutually exclusive, the method also sets the boolean IsActiveSetpoint of the setpoints for pressure and rotational speed to false.

The signature of this Method is specified below. Table 32 and Table 33 specify the Arguments and AddressSpace representation, respectively.

Signature

	SetAndActivateAirflowSetpoint(
		[in]	0:Double		Value)

7.6.3 SetAndActivatePressureSetpoint Method

The Method SetAndActivatePressureSetpoint sets a setpoint for the pressure. The value’s unit is the same as the one specified in object Pressure. Since setpoints are mutually exclusive, the method also sets the boolean IsActiveSetpoint of the setpoints for airflow and rotational speed to false. The signature of this Method is specified below.

Table 34 and Table 35 specify the Arguments and AddressSpace representation, respectively.

Signature

	SetAndActivatePressureSetpoint (
		[in]	0:Double	Value)

7.6.4 SetAndActivateRotationalSpeedSetpoint Method

The Method SetAndActivateRotationalSpeedSetpoint sets a setpoint for the rotational speed. The value’s unit is the same as the one specified in object RotationalSpeed. Since setpoints are mutually exclusive, the method also sets the boolean IsActiveSetpoint of the setpoints for airflow and pressure to false.

The signature of this Method is specified below. Table 36 and Table 37 specify the Arguments and AddressSpace representation, respectively.

Signature

	SetAndActivateRotationalSpeedSetpoint (
		[in]	0:Double	Value)

7.6.5 OperationOn Method

The Method OperationOn turns the machine on. It should only be available on the filter unit if the filter unit is considered a machine, rather than a component of a larger machine. If the filter unit is only a component of a larger machine, the OperationOn Method should be present on the filter system. The method changes the state of MachineryItemState.

Table 38 specifies the AddressSpace representation.

Signature

	OperationOn ()

7.6.6 OperationOff Method

The Method OperationOff turns the machine off. As with the OperationOn Method, this method should be present under the filter unit if and only if the filter unit is considered a machine. The signature of this Method is specified below. Table 39 specifies the AddressSpace representation. The method changes the state of MachineryItemState.

Signature

	OperationOff ()

7.7 AirConnectionType ObjectType Definition

7.7.1 Overview

The AirConnectionType is a non-tangible component representing the state of a connection from the ducting system to a filter unit. The connection can be open or closed. The open state represents a state of the ducting system where air can pass through to the filter unit.

It is formally defined in Table 40.

The Open and Close Methods can be called to open or close the connection. In a complex ducting system that consists of a network of joints and junctions, opening or closing the connection may involve switching multiple valves.

The control logic for switching the state of the ducting system is determined by the server implementation.

The air connection may contain optional sensors for humidity, temperature, air flow, gas quality, and air pressure.

The server sends a MalfunctionAlarmType event when the Malfunction property changes.

The AirConnectionStatusChangedConditionType event is triggered when the ConnectionOpen property changes.

7.7.2 Open Method

The Method Open opens or switches all valves of the ducting system so that the air can pass through to the filter device. The signature of this Method is specified below. Table 42 specifies the AddressSpace representation.

Signature

	Open ()

7.7.3 Close Method

The Method Close closes or switches some of the valves in the ducting system so that no air may pass through the ducting system to the device. The signature of this Method is specified below. Table 43 specifies the AddressSpace representation.

Signature

	Close ()

7.8 FanType ObjectType Definition

The FanType represents a device for generating negative air pressure and is formally defined in Table 44.

The components of the FanType have additional references which are defined in Table 46.

The server sends a MalfunctionAlarmType event when the Malfunction property changes.

The server sends a MaintenanceSwitchOnConditionType event when the physical maintenance switch is turned on.

7.9 TemperatureRegulatorType ObjectType Definition

The TemperatureRegulatorType represents a device for regulating the temperature of the process gas and is formally defined in Table 47.

The components of the TemperatureRegulatorType have additional references which are defined in Table 49.

The server sends a MalfunctionAlarmType event when the Malfunction property changes.

7.10 SafetySystemType ObjectType Definition

The SafetySystemType is a generic component that represents a protective device. Each component in the PAEFS can reference an instance of the safety system via a Uses reference.

It is formally defined in Table 50.

The component Variables of the SafetySystemType have additional Attributes defined in Table 51.

The components of the SafetySystemType have additional references which are defined in Table 52.

The server sends a SafetySystemTriggeredAlarmType event when the safety system is triggered.

The server sends a MalfunctionAlarmType event when the Malfunction property changes.

7.11 FilterAidDeviceType ObjectType Definition

7.11.1 Overview

The FilterAidDeviceType is a device for the application of a filter aid. It is formally defined in Table 53.

The components of the FilterAidDeviceType have additional references which are defined in Table 55.