| /* 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 <open62541/client_config_default.h> |
| #include <open62541/client_highlevel.h> |
| #include <open62541/plugin/log_stdout.h> |
| |
| #include <signal.h> |
| #include <stdlib.h> |
| |
| UA_Boolean running = true; |
| |
| static void stopHandler(int sign) { |
| UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_CLIENT, "Received Ctrl-C"); |
| running = 0; |
| } |
| |
| 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); |
| |
| /* default timeout is 5 seconds. Set it to 1 second here for demo */ |
| cc->timeout = 1000; |
| |
| /* Read the value attribute of the node. UA_Client_readValueAttribute is a |
| * wrapper for the raw read service available as UA_Client_Service_read. */ |
| UA_Variant value; /* Variants can hold scalar values and arrays of any type */ |
| UA_Variant_init(&value); |
| |
| /* Endless loop reading the server time */ |
| 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_CLIENT, "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; |
| } |
| |
| /* NodeId of the variable holding the current time */ |
| const UA_NodeId nodeId = |
| UA_NODEID_NUMERIC(0, UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME); |
| |
| retval = UA_Client_readValueAttribute(client, nodeId, &value); |
| if(retval == UA_STATUSCODE_BADCONNECTIONCLOSED) { |
| UA_LOG_ERROR(UA_Log_Stdout, UA_LOGCATEGORY_CLIENT, |
| "Connection was closed. Reconnecting ..."); |
| continue; |
| } |
| if(retval == UA_STATUSCODE_GOOD && |
| UA_Variant_hasScalarType(&value, &UA_TYPES[UA_TYPES_DATETIME])) { |
| UA_DateTime raw_date = *(UA_DateTime *) 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); |
| } |
| UA_Variant_clear(&value); |
| UA_sleep_ms(1000); |
| }; |
| |
| /* Clean up */ |
| UA_Variant_clear(&value); |
| UA_Client_delete(client); /* Disconnects the client internally */ |
| return EXIT_SUCCESS; |
| } |