/* This work is licensed under a Creative Commons CCZero 1.0 Universal License. * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */ /** * Client disconnect handling * -------------------------- * This example shows you how to handle a client disconnect, e.g., if the server * is shut down while the client is connected. You just need to call connect * again and the client will automatically reconnect. * * This example is very similar to the tutorial_client_firststeps.c. */ #include #include #include #include #include UA_Boolean running = true; static void stopHandler(int sign) { UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Received Ctrl-C"); running = 0; } static void handler_currentTimeChanged(UA_Client *client, UA_UInt32 subId, void *subContext, UA_UInt32 monId, void *monContext, UA_DataValue *value) { UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "currentTime has changed!"); if(UA_Variant_hasScalarType(&value->value, &UA_TYPES[UA_TYPES_DATETIME])) { UA_DateTime raw_date = *(UA_DateTime *) value->value.data; UA_DateTimeStruct dts = UA_DateTime_toStruct(raw_date); UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "date is: %02u-%02u-%04u %02u:%02u:%02u.%03u", dts.day, dts.month, dts.year, dts.hour, dts.min, dts.sec, dts.milliSec); } } static void deleteSubscriptionCallback(UA_Client *client, UA_UInt32 subscriptionId, void *subscriptionContext) { UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Subscription Id %u was deleted", subscriptionId); } static void subscriptionInactivityCallback (UA_Client *client, UA_UInt32 subId, void *subContext) { UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Inactivity for subscription %u", subId); } static void stateCallback(UA_Client *client, UA_SecureChannelState channelState, UA_SessionState sessionState, UA_StatusCode recoveryStatus) { switch(channelState) { case UA_SECURECHANNELSTATE_FRESH: case UA_SECURECHANNELSTATE_CLOSED: UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "The client is disconnected"); break; case UA_SECURECHANNELSTATE_HEL_SENT: UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Waiting for ack"); break; case UA_SECURECHANNELSTATE_OPN_SENT: UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Waiting for OPN Response"); break; case UA_SECURECHANNELSTATE_OPEN: UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "A SecureChannel to the server is open"); break; default: break; } switch(sessionState) { case UA_SESSIONSTATE_ACTIVATED: { UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "A session with the server is activated"); /* A new session was created. We need to create the subscription. */ /* Create a subscription */ UA_CreateSubscriptionRequest request = UA_CreateSubscriptionRequest_default(); UA_CreateSubscriptionResponse response = UA_Client_Subscriptions_create(client, request, NULL, NULL, deleteSubscriptionCallback); if(response.responseHeader.serviceResult == UA_STATUSCODE_GOOD) UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Create subscription succeeded, id %u", response.subscriptionId); else return; /* Add a MonitoredItem */ UA_NodeId currentTimeNode = UA_NODEID_NUMERIC(0, UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME); UA_MonitoredItemCreateRequest monRequest = UA_MonitoredItemCreateRequest_default(currentTimeNode); UA_MonitoredItemCreateResult monResponse = UA_Client_MonitoredItems_createDataChange(client, response.subscriptionId, UA_TIMESTAMPSTORETURN_BOTH, monRequest, NULL, handler_currentTimeChanged, NULL); if(monResponse.statusCode == UA_STATUSCODE_GOOD) UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Monitoring UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME', id %u", monResponse.monitoredItemId); } break; case UA_SESSIONSTATE_CLOSED: UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Session disconnected"); break; default: break; } } int main(void) { signal(SIGINT, stopHandler); /* catches ctrl-c */ UA_Client *client = UA_Client_new(); UA_ClientConfig *cc = UA_Client_getConfig(client); UA_ClientConfig_setDefault(cc); /* Set stateCallback */ cc->stateCallback = stateCallback; cc->subscriptionInactivityCallback = subscriptionInactivityCallback; /* Endless loop runAsync */ while(running) { /* if already connected, this will return GOOD and do nothing */ /* if the connection is closed/errored, the connection will be reset and then reconnected */ /* Alternatively you can also use UA_Client_getState to get the current state */ UA_StatusCode retval = UA_Client_connect(client, "opc.tcp://localhost:4840"); if(retval != UA_STATUSCODE_GOOD) { UA_LOG_ERROR(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "Not connected. Retrying to connect in 1 second"); /* The connect may timeout after 1 second (see above) or it may fail immediately on network errors */ /* E.g. name resolution errors or unreachable network. Thus there should be a small sleep here */ UA_sleep_ms(1000); continue; } UA_Client_run_iterate(client, 1000); }; /* Clean up */ UA_Client_delete(client); /* Disconnects the client internally */ return EXIT_SUCCESS; }