client_subscription_loop.c 5.8 KB

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  1. /* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
  2. * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */
  3. /**
  4. * Client disconnect handling
  5. * --------------------------
  6. * This example shows you how to handle a client disconnect, e.g., if the server
  7. * is shut down while the client is connected. You just need to call connect
  8. * again and the client will automatically reconnect.
  9. *
  10. * This example is very similar to the tutorial_client_firststeps.c. */
  11. #include "open62541.h"
  12. #include <signal.h>
  13. UA_Boolean running = true;
  14. UA_Logger logger = UA_Log_Stdout;
  15. static void stopHandler(int sign) {
  16. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Received Ctrl-C");
  17. running = 0;
  18. }
  19. static void
  20. handler_currentTimeChanged(UA_Client *client, UA_UInt32 subId, void *subContext,
  21. UA_UInt32 monId, void *monContext, UA_DataValue *value) {
  22. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "currentTime has changed!");
  23. if(UA_Variant_hasScalarType(&value->value, &UA_TYPES[UA_TYPES_DATETIME])) {
  24. UA_DateTime raw_date = *(UA_DateTime *) value->value.data;
  25. UA_DateTimeStruct dts = UA_DateTime_toStruct(raw_date);
  26. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "date is: %02u-%02u-%04u %02u:%02u:%02u.%03u",
  27. dts.day, dts.month, dts.year, dts.hour, dts.min, dts.sec, dts.milliSec);
  28. }
  29. }
  30. static void
  31. deleteSubscriptionCallback(UA_Client *client, UA_UInt32 subscriptionId, void *subscriptionContext) {
  32. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Subscription Id %u was deleted", subscriptionId);
  33. }
  34. static void
  35. subscriptionInactivityCallback (UA_Client *client, UA_UInt32 subId, void *subContext) {
  36. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Inactivity for subscription %u", subId);
  37. }
  38. static void
  39. stateCallback (UA_Client *client, UA_ClientState clientState) {
  40. switch(clientState) {
  41. case UA_CLIENTSTATE_DISCONNECTED:
  42. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "The client is disconnected");
  43. break;
  44. case UA_CLIENTSTATE_WAITING_FOR_ACK:
  45. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Waiting for ack");
  46. break;
  47. case UA_CLIENTSTATE_CONNECTED:
  48. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A TCP connection to the server is open");
  49. break;
  50. case UA_CLIENTSTATE_SECURECHANNEL:
  51. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A SecureChannel to the server is open");
  52. break;
  53. case UA_CLIENTSTATE_SESSION:{
  54. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A session with the server is open");
  55. /* A new session was created. We need to create the subscription. */
  56. /* Create a subscription */
  57. UA_CreateSubscriptionRequest request = UA_CreateSubscriptionRequest_default();
  58. UA_CreateSubscriptionResponse response = UA_Client_Subscriptions_create(client, request,
  59. NULL, NULL, deleteSubscriptionCallback);
  60. if(response.responseHeader.serviceResult == UA_STATUSCODE_GOOD)
  61. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Create subscription succeeded, id %u", response.subscriptionId);
  62. else
  63. return;
  64. /* Add a MonitoredItem */
  65. UA_MonitoredItemCreateRequest monRequest =
  66. UA_MonitoredItemCreateRequest_default(UA_NODEID_NUMERIC(0, UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME));
  67. UA_MonitoredItemCreateResult monResponse =
  68. UA_Client_MonitoredItems_createDataChange(client, response.subscriptionId,
  69. UA_TIMESTAMPSTORETURN_BOTH,
  70. monRequest, NULL, handler_currentTimeChanged, NULL);
  71. if(monResponse.statusCode == UA_STATUSCODE_GOOD)
  72. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Monitoring UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME', id %u", monResponse.monitoredItemId);
  73. }
  74. break;
  75. case UA_CLIENTSTATE_SESSION_RENEWED:
  76. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A session with the server is open (renewed)");
  77. /* The session was renewed. We don't need to recreate the subscription. */
  78. break;
  79. case UA_CLIENTSTATE_SESSION_DISCONNECTED:
  80. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Session disconnected");
  81. break;
  82. }
  83. return;
  84. }
  85. int main(void) {
  86. signal(SIGINT, stopHandler); /* catches ctrl-c */
  87. UA_ClientConfig config = UA_ClientConfig_default;
  88. /* Set stateCallback */
  89. config.stateCallback = stateCallback;
  90. config.subscriptionInactivityCallback = subscriptionInactivityCallback;
  91. UA_Client *client = UA_Client_new(config);
  92. /* Endless loop runAsync */
  93. while (running) {
  94. /* if already connected, this will return GOOD and do nothing */
  95. /* if the connection is closed/errored, the connection will be reset and then reconnected */
  96. /* Alternatively you can also use UA_Client_getState to get the current state */
  97. UA_StatusCode retval = UA_Client_connect(client, "opc.tcp://localhost:4840");
  98. if(retval != UA_STATUSCODE_GOOD) {
  99. UA_LOG_ERROR(logger, UA_LOGCATEGORY_USERLAND, "Not connected. Retrying to connect in 1 second");
  100. /* The connect may timeout after 1 second (see above) or it may fail immediately on network errors */
  101. /* E.g. name resolution errors or unreachable network. Thus there should be a small sleep here */
  102. UA_sleep_ms(1000);
  103. continue;
  104. }
  105. UA_Client_run_iterate(client, 1000);
  106. };
  107. /* Clean up */
  108. UA_Client_delete(client); /* Disconnects the client internally */
  109. return UA_STATUSCODE_GOOD;
  110. }