.. _client: Client ====== The client implementation allows remote access to all OPC UA services. For convenience, some functionality has been wrapped in :ref:`high-level abstractions `. **However**: At this time, the client does not yet contain its own thread or event-driven main-loop. So the client will not perform any actions automatically in the background. This is especially relevant for subscriptions. The user will have to periodically call `UA_Client_Subscriptions_manuallySendPublishRequest`. See also :ref:`here `. Client Configuration -------------------- .. code-block:: c typedef UA_Connection (*UA_ConnectClientConnection)(UA_ConnectionConfig localConf, const char *endpointUrl, UA_Logger logger); typedef struct UA_ClientConfig { UA_UInt32 timeout; /* Sync response timeout */ UA_UInt32 secureChannelLifeTime; /* Lifetime in ms (then the channel needs to be renewed) */ UA_Logger logger; UA_ConnectionConfig localConnectionConfig; UA_ConnectClientConnection connectionFunc; } UA_ClientConfig; Client Lifecycle ---------------- .. code-block:: c typedef enum { UA_CLIENTSTATE_READY, /* The client is not connected but initialized and ready to use. */ UA_CLIENTSTATE_CONNECTED, /* The client is connected to a server. */ UA_CLIENTSTATE_FAULTED, /* An error has occured that might have influenced the connection state. A successfull service call or renewal of the secure channel will reset the state to CONNECTED. */ UA_CLIENTSTATE_ERRORED /* A non-recoverable error has occured and the connection is no longer reliable. The client needs to be disconnected and reinitialized to recover into a CONNECTED state. */ } UA_ClientState; struct UA_Client; typedef struct UA_Client UA_Client; /* Create a new client * * @param config for the new client. You can use UA_ClientConfig_standard * which has sane defaults * @param logger function pointer to a logger function. See * examples/logger_stdout.c for a simple implementation * @return return the new Client object */ UA_Client * UA_Client_new(UA_ClientConfig config); /* Get the client connection status */ UA_ClientState UA_Client_getState(UA_Client *client); /* Reset a client */ void UA_Client_reset(UA_Client *client); /* Delete a client */ void UA_Client_delete(UA_Client *client); Manage the Connection --------------------- .. code-block:: c /* Gets a list of endpoints of a server * * @param client to use * @param server url to connect (for example "opc.tcp://localhost:16664") * @param endpointDescriptionsSize size of the array of endpoint descriptions * @param endpointDescriptions array of endpoint descriptions that is allocated * by the function (you need to free manually) * @return Indicates whether the operation succeeded or returns an error code */ UA_StatusCode UA_Client_getEndpoints(UA_Client *client, const char *serverUrl, size_t* endpointDescriptionsSize, UA_EndpointDescription** endpointDescriptions); /* Connect to the selected server * * @param client to use * @param endpointURL to connect (for example "opc.tcp://localhost:16664") * @return Indicates whether the operation succeeded or returns an error code */ UA_StatusCode UA_Client_connect(UA_Client *client, const char *endpointUrl); /* Connect to the selected server with the given username and password * * @param client to use * @param endpointURL to connect (for example "opc.tcp://localhost:16664") * @param username * @param password * @return Indicates whether the operation succeeded or returns an error code */ UA_StatusCode UA_Client_connect_username(UA_Client *client, const char *endpointUrl, const char *username, const char *password); /* Close a connection to the selected server */ UA_StatusCode UA_Client_disconnect(UA_Client *client); /* Renew the underlying secure channel */ UA_StatusCode UA_Client_manuallyRenewSecureChannel(UA_Client *client); .. _client-services: Raw Services ------------ The raw OPC UA services are exposed to the client. But most of them time, it is better to use the convenience functions from ``ua_client_highlevel.h`` that wrap the raw services. .. code-block:: c /* Don't use this function. Use the type versions below instead. */ void __UA_Client_Service(UA_Client *client, const void *request, const UA_DataType *requestType, void *response, const UA_DataType *responseType); Attribute Service Set ^^^^^^^^^^^^^^^^^^^^^ .. code-block:: c static UA_INLINE UA_ReadResponse UA_Client_Service_read(UA_Client *client, const UA_ReadRequest request) { UA_ReadResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_READREQUEST], &response, &UA_TYPES[UA_TYPES_READRESPONSE]); return response; } static UA_INLINE UA_WriteResponse UA_Client_Service_write(UA_Client *client, const UA_WriteRequest request) { UA_WriteResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_WRITEREQUEST], &response, &UA_TYPES[UA_TYPES_WRITERESPONSE]); return response; } Method Service Set ^^^^^^^^^^^^^^^^^^ .. code-block:: c #ifdef UA_ENABLE_METHODCALLS static UA_INLINE UA_CallResponse UA_Client_Service_call(UA_Client *client, const UA_CallRequest request) { UA_CallResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_CALLREQUEST], &response, &UA_TYPES[UA_TYPES_CALLRESPONSE]); return response; } #endif NodeManagement Service Set ^^^^^^^^^^^^^^^^^^^^^^^^^^ .. code-block:: c static UA_INLINE UA_AddNodesResponse UA_Client_Service_addNodes(UA_Client *client, const UA_AddNodesRequest request) { UA_AddNodesResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_ADDNODESREQUEST], &response, &UA_TYPES[UA_TYPES_ADDNODESRESPONSE]); return response; } static UA_INLINE UA_AddReferencesResponse UA_Client_Service_addReferences(UA_Client *client, const UA_AddReferencesRequest request) { UA_AddReferencesResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_ADDREFERENCESREQUEST], &response, &UA_TYPES[UA_TYPES_ADDREFERENCESRESPONSE]); return response; } static UA_INLINE UA_DeleteNodesResponse UA_Client_Service_deleteNodes(UA_Client *client, const UA_DeleteNodesRequest request) { UA_DeleteNodesResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_DELETENODESREQUEST], &response, &UA_TYPES[UA_TYPES_DELETENODESRESPONSE]); return response; } static UA_INLINE UA_DeleteReferencesResponse UA_Client_Service_deleteReferences(UA_Client *client, const UA_DeleteReferencesRequest request) { UA_DeleteReferencesResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_DELETEREFERENCESREQUEST], &response, &UA_TYPES[UA_TYPES_DELETEREFERENCESRESPONSE]); return response; } View Service Set ^^^^^^^^^^^^^^^^ .. code-block:: c static UA_INLINE UA_BrowseResponse UA_Client_Service_browse(UA_Client *client, const UA_BrowseRequest request) { UA_BrowseResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_BROWSEREQUEST], &response, &UA_TYPES[UA_TYPES_BROWSERESPONSE]); return response; } static UA_INLINE UA_BrowseNextResponse UA_Client_Service_browseNext(UA_Client *client, const UA_BrowseNextRequest request) { UA_BrowseNextResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_BROWSENEXTREQUEST], &response, &UA_TYPES[UA_TYPES_BROWSENEXTRESPONSE]); return response; } static UA_INLINE UA_TranslateBrowsePathsToNodeIdsResponse UA_Client_Service_translateBrowsePathsToNodeIds(UA_Client *client, const UA_TranslateBrowsePathsToNodeIdsRequest request) { UA_TranslateBrowsePathsToNodeIdsResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_TRANSLATEBROWSEPATHSTONODEIDSREQUEST], &response, &UA_TYPES[UA_TYPES_TRANSLATEBROWSEPATHSTONODEIDSRESPONSE]); return response; } static UA_INLINE UA_RegisterNodesResponse UA_Client_Service_registerNodes(UA_Client *client, const UA_RegisterNodesRequest request) { UA_RegisterNodesResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_REGISTERNODESREQUEST], &response, &UA_TYPES[UA_TYPES_REGISTERNODESRESPONSE]); return response; } static UA_INLINE UA_UnregisterNodesResponse UA_Client_Service_unregisterNodes(UA_Client *client, const UA_UnregisterNodesRequest request) { UA_UnregisterNodesResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_UNREGISTERNODESREQUEST], &response, &UA_TYPES[UA_TYPES_UNREGISTERNODESRESPONSE]); return response; } Query Service Set ^^^^^^^^^^^^^^^^^ .. code-block:: c static UA_INLINE UA_QueryFirstResponse UA_Client_Service_queryFirst(UA_Client *client, const UA_QueryFirstRequest request) { UA_QueryFirstResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_QUERYFIRSTREQUEST], &response, &UA_TYPES[UA_TYPES_QUERYFIRSTRESPONSE]); return response; } static UA_INLINE UA_QueryNextResponse UA_Client_Service_queryNext(UA_Client *client, const UA_QueryNextRequest request) { UA_QueryNextResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_QUERYFIRSTREQUEST], &response, &UA_TYPES[UA_TYPES_QUERYFIRSTRESPONSE]); return response; } #ifdef UA_ENABLE_SUBSCRIPTIONS MonitoredItem Service Set ^^^^^^^^^^^^^^^^^^^^^^^^^ .. code-block:: c static UA_INLINE UA_CreateMonitoredItemsResponse UA_Client_Service_createMonitoredItems(UA_Client *client, const UA_CreateMonitoredItemsRequest request) { UA_CreateMonitoredItemsResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_CREATEMONITOREDITEMSREQUEST], &response, &UA_TYPES[UA_TYPES_CREATEMONITOREDITEMSRESPONSE]); return response; } static UA_INLINE UA_DeleteMonitoredItemsResponse UA_Client_Service_deleteMonitoredItems(UA_Client *client, const UA_DeleteMonitoredItemsRequest request) { UA_DeleteMonitoredItemsResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_DELETEMONITOREDITEMSREQUEST], &response, &UA_TYPES[UA_TYPES_DELETEMONITOREDITEMSRESPONSE]); return response; } Subscription Service Set ^^^^^^^^^^^^^^^^^^^^^^^^ .. code-block:: c static UA_INLINE UA_CreateSubscriptionResponse UA_Client_Service_createSubscription(UA_Client *client, const UA_CreateSubscriptionRequest request) { UA_CreateSubscriptionResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_CREATESUBSCRIPTIONREQUEST], &response, &UA_TYPES[UA_TYPES_CREATESUBSCRIPTIONRESPONSE]); return response; } static UA_INLINE UA_ModifySubscriptionResponse UA_Client_Service_modifySubscription(UA_Client *client, const UA_ModifySubscriptionRequest request) { UA_ModifySubscriptionResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_MODIFYSUBSCRIPTIONREQUEST], &response, &UA_TYPES[UA_TYPES_MODIFYSUBSCRIPTIONRESPONSE]); return response; } static UA_INLINE UA_DeleteSubscriptionsResponse UA_Client_Service_deleteSubscriptions(UA_Client *client, const UA_DeleteSubscriptionsRequest request) { UA_DeleteSubscriptionsResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_DELETESUBSCRIPTIONSREQUEST], &response, &UA_TYPES[UA_TYPES_DELETESUBSCRIPTIONSRESPONSE]); return response; } static UA_INLINE UA_PublishResponse UA_Client_Service_publish(UA_Client *client, const UA_PublishRequest request) { UA_PublishResponse response; __UA_Client_Service(client, &request, &UA_TYPES[UA_TYPES_PUBLISHREQUEST], &response, &UA_TYPES[UA_TYPES_PUBLISHRESPONSE]); return response; } #endif .. toctree:: client_highlevel