Client¶
The client implementation allows remote access to all OPC UA services. For convenience, some functionality has been wrapped in 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 here.
Client Configuration¶
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¶
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¶
/* 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);
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.
/* 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¶
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¶
#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¶
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¶
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¶
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¶
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¶
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