OPC UA OPC Unified Architecture

Transcription

1 OPC Unified Architecture

2 Content 1. Motivation 2. An Overview of Distributed Software Architecture Approaches 2.1 Pro & Contra Middleware 2.2 Message-Based Architectures 2.3 Service-Based Architectures 2.4 Subscribe-Based Architectures 2.5 Component-Based Architectures 3. Inter-Process-Communication (IPC) in Unix 4. Example: MPI 5. Example: Web Services 6. Example: OPC UA 7. Critical Sections and Deadlocks 8. Example: DDS 9. Example: OSGi 10. Redundancy and Consistency 11. MultiCore Programming and Synchronous Languages

3 Introduction Successor of the OPC protocol will be standardized as IEC first version in 2006 current version in 2009

4 Introduction Message Serialization: XML or binary Message Security: Web Service Security or UA binary security Message Transport: TCP or HTTP/SOAP OPC UA Client OPC UA Server OPC UA Client SDK OPC UA Server SDK OPC UA Stack Message Serialization Message Security Message Transport OPC UA Stack Message Serialization Message Security Message Transport

5 Introduction OPC UA has two main components: 1. the OPC UA information model 2. the API to access data, events, and the information model The information model allows for an explicit modeling of the data syntax and its semantics OPC UA API OPC UA Information Model OPC UA Server

6 Information Model The information model comprises data, data types, references, etc., i.e. the information model comprises instances and the meta layer (inner meta layers) The data type information and the data items themselves are accessed via the same API, i.e. the APIs support reflection OPC UA Information Model Meta-Model Outer Meta Layers Data types and the data themselves are modeled explicitly using the OPC UA information model meta-model (outer meta layers) Type Levels Inner Meta Layers Instance Level

7 Information Model The OPC UA information model meta-model comprises 1. nodes, 2. their attributes, and 3. references Node Attributes Node Attributes Nodes have the following attributes NodeID: unique ID in the address space NodeClass: e.g. object, method, type,... BrowseName: non localized name DisplayName: localized name... Node Attributes Reference

8 Information Model The OPC UA information model meta-model comprises 1. nodes, 2. their attributes, and 3. references References comprise source NodeID target NodeID direction of the reference Semantic of the reference defined as ReferenceType, ReferenceTypes are nodes Node Attributes Node Attributes Node Attributes Reference Additional attributes of ReferenceTypes: Symmetric: same meaning in both directions? InverseName: semantic of backward direction IsAbstract: can not be used directly

9 Information Model The following ReferenceTypes are defined by OPC UA and can be extended: References HierarchicalReferences NonHierarchicalReferences HasChild Organize HasTypeDefinition Aggregates HasComponent HasSubtype HasSubtype reference ReferenceType

10 Information Model NodeClasses: Variable: Stores a value (data or meta information) Clients can read, write and subscribe to variables Additional attributes: Value DataType: NodeID of the type of the value ValueRank: Array?... Method: Represent method calls; methods calls are defined by their input and output arguments, these arguments are defined by variables (called properties here) beneath the method Object: Objects structure the OPC UA server address space; objects comprise objects, variables, and methods Additional attributes: EventNotifier: Objects can generate events

11 Information Model NodeClasses: ObjectType: ObjectTypes type objects, ObjectTypes can use inheritance ObjectTypes can be simple: Sensor DisplayName "Sensor" NodeClass = ObjectType Sensor42 DisplayName "Sensor42" NodeClass = Object I/O Sensor DisplayName "I/O Sensor" NodeClass = ObjectType HasType Reference HasSubtype Reference

12 Information Model Types of nodes can also be complex: Sensor DisplayName "Sensor" NodeClass = ObjectType Sensor42 DisplayName "Sensor42" NodeClass = Object Temperature DisplayName "Temperature" NodeClass = Variable Temperature DisplayName "Temperature" NodeClass = Variable Calibrate DisplayName "Calibrate" NodeClass = Method Calibrate DisplayName "Calibrate" NodeClass = Method Provider DisplayName "Provider" NodeClass = Object Address DisplayName "Address" NodeClass = Variable Provider DisplayName "Provider" NodeClass = Object Address DisplayName "Address" NodeClass = Variable HasType Reference HasComponent Reference

13 Information Model NodeClasses: VariableType: VariableTypes behave as ObjectType but do not allow objects or method beneath the type definition

14 OPC UA API The OPC UA API is defined language-independent Each method is defined by a request (defined by a set of parameters) and a response (defined by a set of parameters) The general procedure is as follows: 1. find servers 2. establish connection 3. find information in the address space 4. access information - read/write/subscribe to data and/or meta information - call methods - access historical data - modify structure of the address space 5. close connection

15 OPC UA API The OPC UA API is defined language-independent Each method is defined by a request (defined by a set of parameters) and a response (defined by a set of parameters)

16 1. Find Server API OPC UA API RegisterServer: register specific server at the discovery server FindServer: find specific server at the discovery server GetEndpoints: get connection information from specific server

17 FindServer-Methode <ua:server> <ua:applicationuri>urn:somehost:myserver</ua:applicationuri> <ua:applicationtype>server_1</ua:applicationtype> <ua:discoveryurls> <ua:string> </ua:discoveryurls> </ua:server>

18 GetEndpoint-Methode <EndpointDescription> <ua:endpointurl> <ua:server> <ua:applicationuri>urn:somehost:myserver</ua:applicationuri> <ua:applicationtype>server_1</ua:applicationtype> <ua:discoveryurls> <ua:string> </ua:discoveryurls> </ua:server> <ua:servercertificate>...</ua:servercertificate> <ua:securitymode>signandencrypt_3</ua:securitymode> <ua:securitypolicyuri> SecurityPolicy#Basic128Rsa15</ua:SecurityPolicyUri> <ua:useridentitytokens /> <TransportProfileUri> transport/wsxml</transportprofileuri> <ua:securitylevel>1</ua:securitylevel> </EndpointDescription>

19 2. Establish Connection OpenSecureChannel: open secure channel OPC UA Stack OPC UA API Message Serialization Message Security Message Transport CreateSession: creates a session between two applications ActivateSession: activates channel, assigns secure channel

20 OPC UA API 3. Find Information in the Address Space Browse: get description including all references for one or several specific NodeIDs TranslateBrowsePathToNodeIds: pathname-like node description is translated to NodeIDs

21 OPC UA API 4. Access Information Read: reads values of NodeIDs Write: writes values of NodeIDs Call: Calls a method HistoryRead: Reads historic data

22 OPC UA API 4. Access Information Subscriptions are skipped here...

23 OPC UA API 4. Modify Information in the Address Space AddNode: creates a new node, parent node and type must be provided AddReference: add reference between two nodes DeleteNode: removes a node DeleteReference: removes a reference

24 5. Close Connection CloseSecureChannel: close secure channel CloseSession OPC UA Stack OPC UA API Message Serialization Message Security Message Transport

25 Beispiel Grundstruktur einer SOAP- Nachricht <v:envelope xmlns:i=" xmlns:d=" xmlns:v=" <v:header> <d:action> </d:action> </v:header> <v:body> <! hier kommen die Daten rein --> </v:body> </v:envelope>

26 Beispiel Response <?xml version="1.0"?> <s:envelope xmlns:s=" envelope" xmlns:a=" <s:header> <a:action s:mustunderstand="1"> </s:header> <s:body> <PublishResponse xmlns=" xmlns:i=" instance"> <ResponseHeader> <Timestamp> T09:33:16.359Z</Timestamp> <RequestHandle>0</RequestHandle> <ServiceResult> </ServiceResult> <ServiceDiagnostics i:nil="true"/> <StringTable/> <AdditionalHeader i:nil="true"/> </ResponseHeader> <SubscriptionId>2</SubscriptionId> <AvailableSequenceNumbers> <UInt32>194</UInt32> <UInt32>195</UInt32> <UInt32>196</UInt32> <UInt32>197</UInt32> <UInt32>198</UInt32> <UInt32>199</UInt32> <UInt32>200</UInt32> <UInt32>201</UInt32> <UInt32>202</UInt32> </AvailableSequenceNumbers> <MoreNotifications>false</MoreNotifications> <NotificationMessage> <SequenceNumber>202</SequenceNumber> <PublishTime> T09:33:16.359Z</PublishTime> <NotificationData> <ExtensionObject> <TypeId> <Identifier>i=810</Identifier> </TypeId> <Body> <DataChangeNotification> <MonitoredItems> <MonitoredItemNotification> <ClientHandle>15</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds>

27 Beispiel Response <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification> <MonitoredItemNotification> <ClientHandle>26</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification> <MonitoredItemNotification> <ClientHandle>27</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification> <MonitoredItemNotification> <ClientHandle>13</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp>

28 Beispiel Response </MonitoredItemNotification> <MonitoredItemNotification> <ClientHandle>25</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification> <MonitoredItemNotification> <ClientHandle>24</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification> <MonitoredItemNotification> <ClientHandle>10</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification> <MonitoredItemNotification> <ClientHandle>9</ClientHandle>

29 Beispiel Response <ClientHandle>9</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>7</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>0</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>3</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp>

30 Beispiel Response <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>23</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00 </ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>6</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>22</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp>

31 Beispiel Response </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>1</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>12</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification><MonitoredItemNotification> <ClientHandle>4</ClientHandle> <Float> </Float> <StatusCode> <SourceTimestamp> T00:00:00</SourceTimestamp> <SourcePicoseconds>0</SourcePicoseconds> <ServerTimestamp> T00:00:00</ServerTimestamp> </MonitoredItemNotification> </MonitoredItems> <DiagnosticInfos/> </DataChangeNotification> </Body> Sonntag, 26. </ExtensionObject> Mai 13

32 Beispiel Response </Body> </ExtensionObject> </NotificationData> </NotificationMessage> <Results/> <DiagnosticInfos/> </PublishResponse> </s:body> </s:envelope>

33 Beispiel The same response as a binary message <?xml version="1.0" encoding="utf- 8"?> <s:envelope xmlns:s=" envelope" xmlns:a=" <s:header> <a:action s:mustunderstand="1"> </s:header> <s:body> f312e f4b0d0a436f6e74656e742d4c656e a d0a436f6e74656e742d a c f6e2f736f61702b786d6c3b d d 380d0a a204d f736f66742d f312e300d0a a204d6f6e2c a34303a d540d0a0d0a3c733a456e76656c6f d 6c6e733a733d a2f2f e77332e6f72672f f3035f736f61702d656e76656c6f d6c6e733a613d a2f2f e77332e6f72672f f30382f e67223e3c733a e3c613a f6e20733a6d e e643d e a2f2f6f f756e f6e2e6f72672f55412f f30322f e c2f f6e73653c2f613a f6e3e3c2f733a e3c733a426f64793e3c f6e d6c6e733d a2f2f6f f7 56e f6e2e6f72672f55412f f30322f e d6c6e733a693d a2f2f e77332e6f72672f f584d4c d612d696e e e3 c f6e e3c54696d d703e d31322d a34303a33362e a3c2f54696d d703e3c e646c653e303c2f e646c653e3c c743e3c436f64653e303c2f436f64653e3c2f c743e3c e6f a6e696c3d f3e3 c e c652f3e3c f6e616c a6e696c3d f3e3c2f f6e e3c c74733e3c c75653e3c56616c7 5653e3c56616c75653e3c4e6f e3c e e6e733d323b733d303a4c4d463c2f e e3c2f4e6f e3c2f56616c75653e3c2f56616c75653e3c f64653e3c436f64653e303c2f436f64653e3c2f f64653e3c536f d d703e d30312d a30303a30303c2f536f d d703e3c5 36f f f6e64733e303c2f536f f f6e64733e3c d d703e d30312d a30303a30303c2f d d703e3c f f6e64733e303c2f f f6e64733e3c2f c75653e3c c75653e3c56616c75653e3c56616c75653e3c496e e313c2f496e e3c2f56616c75653e3c2f56616c75653e3c f64653e3c436f6465 </s:body> </s:envelope>

34 Beispiel TCP Transport