open62541/examples/server_variable.c

/* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
 * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */

#include <signal.h>
#include "open62541.h"

UA_Boolean running = true;
UA_Logger logger = UA_Log_Stdout;

static void stopHandler(int sign) {
    UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "received ctrl-c");
    running = false;
}

static void onRead(void *handle, const UA_NodeId nodeid, const UA_Variant *data,
                   const UA_NumericRange *range) {
    UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "onRead; handle is: %i",
                (uintptr_t)handle);
}

static void onWrite(void *h, const UA_NodeId nodeid, const UA_Variant *data,
                    const UA_NumericRange *range) {
    UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "onWrite; handle: %i",
                (uintptr_t)h);
}

int main(int argc, char** argv) {
    signal(SIGINT, stopHandler); /* catches ctrl-c */

    UA_ServerConfig config = UA_ServerConfig_standard;
    UA_ServerNetworkLayer nl;
    nl = UA_ServerNetworkLayerTCP(UA_ConnectionConfig_standard, 16664);
    config.networkLayers = &nl;
    config.networkLayersSize = 1;
    UA_Server *server = UA_Server_new(config);

    /* 1) Define the attribute of the myInteger variable node */
    UA_VariableAttributes attr;
    UA_VariableAttributes_init(&attr);
    UA_Int32 myInteger = 42;
    UA_Variant_setScalar(&attr.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
    attr.description = UA_LOCALIZEDTEXT("en_US","the answer");
    attr.displayName = UA_LOCALIZEDTEXT("en_US","the answer");

    /* 2) Add the variable node to the information model */
    UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "the.answer");
    UA_QualifiedName myIntegerName = UA_QUALIFIEDNAME(1, "the answer");
    UA_NodeId parentNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER);
    UA_NodeId parentReferenceNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES);
    UA_Server_addVariableNode(server, myIntegerNodeId, parentNodeId,
                              parentReferenceNodeId, myIntegerName,
                              UA_NODEID_NULL, attr, NULL, NULL);

    UA_ValueCallback callback = {(void*)7, onRead, onWrite};
    UA_Server_setVariableNode_valueCallback(server, myIntegerNodeId, callback);

    /* 3) Write another value */
    myInteger = 43;
    UA_Variant myVar;
    UA_Variant_init(&myVar);
    UA_Variant_setScalar(&myVar, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
    UA_Server_writeValue(server, myIntegerNodeId, myVar);

    /* 4) Set the status code of the value */
    UA_WriteValue wv;
    UA_WriteValue_init(&wv);
    wv.nodeId = myIntegerNodeId;
    wv.attributeId = UA_ATTRIBUTEID_VALUE;
    wv.value.status = UA_STATUSCODE_BADNOTCONNECTED;
    wv.value.hasStatus = true;
    UA_Server_write(server, &wv);

    /* 5) Reset to a good statuscode with a value */
    wv.value.hasStatus = false;
    wv.value.value = myVar;
    wv.value.hasValue = true;
    UA_Server_write(server, &wv);

    UA_StatusCode retval = UA_Server_run(server, &running);
    UA_Server_delete(server);
    nl.deleteMembers(&nl);

    return (int)retval;
}