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d715db1057
For consistency we recommend using non-amalgamation install, thus the examples should also use the non-amalgamated headers.
124 lines
4.4 KiB
C
124 lines
4.4 KiB
C
/* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
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* See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */
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/**
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* Adding Variables to a Server
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* ----------------------------
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*
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* This tutorial shows how to work with data types and how to add variable nodes
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* to a server. First, we add a new variable to the server. Take a look at the
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* definition of the ``UA_VariableAttributes`` structure to see the list of all
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* attributes defined for VariableNodes.
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*
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* Note that the default settings have the AccessLevel of the variable value as
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* read only. See below for making the variable writable.
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*/
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#include <ua_server.h>
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#include <ua_config_default.h>
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#include <ua_log_stdout.h>
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#include <signal.h>
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static void
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addVariable(UA_Server *server) {
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/* Define the attribute of the myInteger variable node */
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UA_VariableAttributes attr = UA_VariableAttributes_default;
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UA_Int32 myInteger = 42;
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UA_Variant_setScalar(&attr.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
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attr.description = UA_LOCALIZEDTEXT("en-US","the answer");
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attr.displayName = UA_LOCALIZEDTEXT("en-US","the answer");
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attr.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
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attr.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
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/* Add the variable node to the information model */
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UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "the.answer");
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UA_QualifiedName myIntegerName = UA_QUALIFIEDNAME(1, "the answer");
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UA_NodeId parentNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER);
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UA_NodeId parentReferenceNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES);
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UA_Server_addVariableNode(server, myIntegerNodeId, parentNodeId,
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parentReferenceNodeId, myIntegerName,
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UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr, NULL, NULL);
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}
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/**
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* Now we change the value with the write service. This uses the same service
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* implementation that can also be reached over the network by an OPC UA client.
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*/
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static void
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writeVariable(UA_Server *server) {
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UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "the.answer");
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/* Write a different integer value */
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UA_Int32 myInteger = 43;
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UA_Variant myVar;
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UA_Variant_init(&myVar);
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UA_Variant_setScalar(&myVar, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
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UA_Server_writeValue(server, myIntegerNodeId, myVar);
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/* Set the status code of the value to an error code. The function
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* UA_Server_write provides access to the raw service. The above
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* UA_Server_writeValue is syntactic sugar for writing a specific node
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* attribute with the write service. */
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UA_WriteValue wv;
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UA_WriteValue_init(&wv);
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wv.nodeId = myIntegerNodeId;
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wv.attributeId = UA_ATTRIBUTEID_VALUE;
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wv.value.status = UA_STATUSCODE_BADNOTCONNECTED;
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wv.value.hasStatus = true;
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UA_Server_write(server, &wv);
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/* Reset the variable to a good statuscode with a value */
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wv.value.hasStatus = false;
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wv.value.value = myVar;
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wv.value.hasValue = true;
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UA_Server_write(server, &wv);
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}
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/**
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* Note how we initially set the DataType attribute of the variable node to the
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* NodeId of the Int32 data type. This forbids writing values that are not an
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* Int32. The following code shows how this consistency check is performed for
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* every write.
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*/
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static void
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writeWrongVariable(UA_Server *server) {
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UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "the.answer");
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/* Write a string */
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UA_String myString = UA_STRING("test");
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UA_Variant myVar;
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UA_Variant_init(&myVar);
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UA_Variant_setScalar(&myVar, &myString, &UA_TYPES[UA_TYPES_STRING]);
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UA_StatusCode retval = UA_Server_writeValue(server, myIntegerNodeId, myVar);
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printf("Writing a string returned statuscode %s\n", UA_StatusCode_name(retval));
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}
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/** It follows the main server code, making use of the above definitions. */
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UA_Boolean running = true;
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static void stopHandler(int sign) {
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UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_SERVER, "received ctrl-c");
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running = false;
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}
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int main(void) {
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signal(SIGINT, stopHandler);
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signal(SIGTERM, stopHandler);
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UA_ServerConfig *config = UA_ServerConfig_new_default();
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UA_Server *server = UA_Server_new(config);
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addVariable(server);
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writeVariable(server);
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writeWrongVariable(server);
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UA_StatusCode retval = UA_Server_run(server, &running);
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UA_Server_delete(server);
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UA_ServerConfig_delete(config);
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return (int)retval;
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}
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