/* This work is licensed under a Creative Commons CCZero 1.0 Universal License. * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */ /** * .. _pubsub-tutorial: * * Working with Publish/Subscribe * ------------------------------ * * Work in progress: * This Tutorial will be continuously extended during the next PubSub batches. More details about * the PubSub extension and corresponding open62541 API are located here: :ref:`pubsub`. * * Publishing Fields * ^^^^^^^^^^^^^^^^^ * The PubSub publish example demonstrate the simplest way to publish * informations from the information model over UDP multicast using * the UADP encoding. * * **Connection handling** * PubSubConnections can be created and deleted on runtime. More details about the system preconfiguration and * connection can be found in ``tutorial_pubsub_connection.c``. */ #include #include "open62541.h" UA_NodeId connectionIdent, publishedDataSetIdent, writerGroupIdent; static void addPubSubConnection(UA_Server *server){ /* Details about the connection configuration and handling are located * in the pubsub connection tutorial */ UA_PubSubConnectionConfig connectionConfig; memset(&connectionConfig, 0, sizeof(connectionConfig)); connectionConfig.name = UA_STRING("UDP-UADP Connection 1"); connectionConfig.transportProfileUri = UA_STRING("http://opcfoundation.org/UA-Profile/Transport/pubsub-udp-uadp"); connectionConfig.enabled = UA_TRUE; UA_NetworkAddressUrlDataType networkAddressUrl = {UA_STRING_NULL , UA_STRING("opc.udp://224.0.0.22:4840/")}; UA_Variant_setScalar(&connectionConfig.address, &networkAddressUrl, &UA_TYPES[UA_TYPES_NETWORKADDRESSURLDATATYPE]); connectionConfig.publisherId.numeric = UA_UInt32_random(); UA_Server_addPubSubConnection(server, &connectionConfig, &connectionIdent); } /** * **PublishedDataSet handling** * The PublishedDataSet (PDS) and PubSubConnection are the toplevel entities and can exist alone. The PDS contains * the collection of the published fields. * All other PubSub elements are directly or indirectly linked with the PDS or connection. */ static void addPublishedDataSet(UA_Server *server) { /* The PublishedDataSetConfig contains all necessary public * informations for the creation of a new PublishedDataSet */ UA_PublishedDataSetConfig publishedDataSetConfig; memset(&publishedDataSetConfig, 0, sizeof(UA_PublishedDataSetConfig)); publishedDataSetConfig.publishedDataSetType = UA_PUBSUB_DATASET_PUBLISHEDITEMS; publishedDataSetConfig.name = UA_STRING("Demo PDS"); /* Create new PublishedDataSet based on the PublishedDataSetConfig. */ UA_Server_addPublishedDataSet(server, &publishedDataSetConfig, &publishedDataSetIdent); } /** * **DataSetField handling** * The DataSetField (DSF) is part of the PDS and describes exactly one published field. */ static void addDataSetField(UA_Server *server) { /* Add a field to the previous created PublishedDataSet */ UA_NodeId dataSetFieldIdent; UA_DataSetFieldConfig dataSetFieldConfig; memset(&dataSetFieldConfig, 0, sizeof(UA_DataSetFieldConfig)); dataSetFieldConfig.dataSetFieldType = UA_PUBSUB_DATASETFIELD_VARIABLE; dataSetFieldConfig.field.variable.fieldNameAlias = UA_STRING("Server localtime"); dataSetFieldConfig.field.variable.promotedField = UA_FALSE; dataSetFieldConfig.field.variable.publishParameters.publishedVariable = UA_NODEID_NUMERIC(0, UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME); dataSetFieldConfig.field.variable.publishParameters.attributeId = UA_ATTRIBUTEID_VALUE; UA_Server_addDataSetField(server, publishedDataSetIdent, &dataSetFieldConfig, &dataSetFieldIdent); } /** * **WriterGroup handling** * The WriterGroup (WG) is part of the connection and contains the primary configuration * parameters for the message creation. */ static void addWriterGroup(UA_Server *server) { /* Now we create a new WriterGroupConfig and add the group to the existing PubSubConnection. */ UA_WriterGroupConfig writerGroupConfig; memset(&writerGroupConfig, 0, sizeof(UA_WriterGroupConfig)); writerGroupConfig.name = UA_STRING("Demo WriterGroup"); writerGroupConfig.publishingInterval = 100; writerGroupConfig.enabled = UA_FALSE; writerGroupConfig.writerGroupId = 100; writerGroupConfig.encodingMimeType = UA_PUBSUB_ENCODING_UADP; /* The configuration flags for the messages are encapsulated inside the * message- and transport settings extension objects. These extension objects * are defined by the standard. e.g. UadpWriterGroupMessageDataType */ UA_Server_addWriterGroup(server, connectionIdent, &writerGroupConfig, &writerGroupIdent); } /** * **DataSetWriter handling** * A DataSetWriter (DSW) is the glue between the WG and the PDS. The DSW is linked to exactly one * PDS and contains additional informations for the message generation. */ static void addDataSetWriter(UA_Server *server) { /* We need now a DataSetWriter within the WriterGroup. This means we must * create a new DataSetWriterConfig and add call the addWriterGroup function. */ UA_NodeId dataSetWriterIdent; UA_DataSetWriterConfig dataSetWriterConfig; memset(&dataSetWriterConfig, 0, sizeof(UA_DataSetWriterConfig)); dataSetWriterConfig.name = UA_STRING("Demo DataSetWriter"); dataSetWriterConfig.dataSetWriterId = 62541; dataSetWriterConfig.keyFrameCount = 10; UA_Server_addDataSetWriter(server, writerGroupIdent, publishedDataSetIdent, &dataSetWriterConfig, &dataSetWriterIdent); } /** * That's it! You're now publishing the selected fields. * Open a packet inspection tool of trust e.g. wireshark and take a look on the outgoing packages. * The following graphic figures out the packages created by this tutorial. * * .. figure:: ua-wireshark-pubsub.png * :figwidth: 100 % * :alt: OPC UA PubSub communication in wireshark * * The open62541 subscriber API will be released later. If you want to process the the datagrams, * take a look on the ua_network_pubsub_networkmessage.c which already contains the decoding code for UADP messages. * * It follows the main server code, making use of the above definitions. */ UA_Boolean running = true; static void stopHandler(int sign) { UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_SERVER, "received ctrl-c"); running = false; } int main(void) { signal(SIGINT, stopHandler); signal(SIGTERM, stopHandler); UA_StatusCode retval = UA_STATUSCODE_GOOD; UA_ServerConfig *config = UA_ServerConfig_new_default(); /* Details about the connection configuration and handling are located in the pubsub connection tutorial */ config->pubsubTransportLayers = (UA_PubSubTransportLayer *) UA_malloc(sizeof(UA_PubSubTransportLayer)); if(!config->pubsubTransportLayers) { UA_ServerConfig_delete(config); return -1; } config->pubsubTransportLayers[0] = UA_PubSubTransportLayerUDPMP(); config->pubsubTransportLayersSize++; UA_Server *server = UA_Server_new(config); addPubSubConnection(server); addPublishedDataSet(server); addDataSetField(server); addWriterGroup(server); addDataSetWriter(server); retval |= UA_Server_run(server, &running); UA_Server_delete(server); UA_ServerConfig_delete(config); return (int)retval; }