Subscriber Realtime example using custom nodesΒΆ

The purpose of this example file is to use the custom nodes of the XML file(subDataModel.xml) for subscriber. This Subscriber example uses the two custom nodes (SubscriberCounterVariable and Pressure) created using the XML file(subDataModel.xml) for subscribing the packet. The subDataModel.csv will contain the nodeids of custom nodes(object and variables) and the nodeids of the custom nodes are harcoded inside the addSubscribedVariables API

This example uses two threads namely the Subscriber and UserApplication. The Subscriber thread is used to subscribe to data at every cycle. The UserApplication thread serves the functionality of the Control loop, which reads the Information Model of the Subscriber and the new counterdata will be written in the csv along with received timestamp.

Run steps of the Subscriber application as mentioned below:

./bin/examples/pubsub_nodeset_rt_subscriber -i <iface>

For more information run ./bin/examples/pubsub_nodeset_rt_subscriber -h.

#define _GNU_SOURCE

/* For thread operations */
#include <pthread.h>

#include <open62541/server.h>
#include <open62541/server_config_default.h>
#include <open62541/plugin/log_stdout.h>
#include <open62541/types_generated.h>

#include "ua_pubsub.h"
#include "open62541/namespace_example_subscriber_generated.h"

UA_NodeId readerGroupIdentifier;
UA_NodeId readerIdentifier;
UA_DataSetReaderConfig readerConfig;

/* to find load of each thread
 * ps -L -o pid,pri,%cpu -C pubsub_nodeset_rt_subscriber*/

/* Configurable Parameters */
/* Cycle time in milliseconds */
#define             DEFAULT_CYCLE_TIME                    0.25
/* Qbv offset */
#define             QBV_OFFSET                            25 * 1000
#define             DEFAULT_SOCKET_PRIORITY               3
#define             PUBLISHER_ID_SUB                      2234
#define             WRITER_GROUP_ID_SUB                   101
#define             DATA_SET_WRITER_ID_SUB                62541
#define             SUBSCRIBING_MAC_ADDRESS               "opc.eth://01-00-5E-7F-00-01:8.3"
#define             PORT_NUMBER                           62541

/* Non-Configurable Parameters */
/* Milli sec and sec conversion to nano sec */
#define             MILLI_SECONDS                         1000 * 1000
#define             SECONDS                               1000 * 1000 * 1000
#define             SECONDS_SLEEP                         5
#define             DEFAULT_SUB_SCHED_PRIORITY            81
#define             MAX_MEASUREMENTS                      30000000
#define             DEFAULT_PUBSUB_CORE                   2
#define             DEFAULT_USER_APP_CORE                 3
#define             SECONDS_INCREMENT                     1
#define             CLOCKID                               CLOCK_TAI
#define             ETH_TRANSPORT_PROFILE                 "http://opcfoundation.org/UA-Profile/Transport/pubsub-eth-uadp"
#define             DEFAULT_USERAPPLICATION_SCHED_PRIORITY 75

/* Below mentioned parameters can be provided as input using command line arguments
 * If user did not provide the below mentioned parameters as input through command line
 * argument then default value will be used */
static UA_Double  cycleTimeMsec   = DEFAULT_CYCLE_TIME;
static UA_Boolean consolePrint    = UA_FALSE;
static UA_Int32   subPriority     = DEFAULT_SUB_SCHED_PRIORITY;
static UA_Int32   userAppPriority = DEFAULT_USERAPPLICATION_SCHED_PRIORITY;
static UA_Int32   pubSubCore      = DEFAULT_PUBSUB_CORE;
static UA_Int32   userAppCore     = DEFAULT_USER_APP_CORE;
/* User application Pub will wakeup at the 30% of cycle time and handles the */
/* user data write in Information model */
/* After 60% is left for publisher */
static UA_Double  userAppWakeupPercentage = 0.3;
/* Subscriber will wake up at the start of cycle time and then receives the packet */
static UA_Double  subWakeupPercentage     = 0;
static UA_Boolean fileWrite = UA_FALSE;

/* Set server running as true */
UA_Boolean          running                = UA_TRUE;
UA_UInt16           nsIdx = 0;

UA_UInt64           *subCounterData;
UA_DataValue        *subDataValueRT;
UA_Double           *pressureData;
UA_DataValue        *pressureValueRT;

/* File to store the data and timestamps for different traffic */
FILE               *fpSubscriber;
char               *fileName     = "subscriber_T4.csv";
/* Array to store subscribed counter data */
UA_UInt64           subscribeCounterValue[MAX_MEASUREMENTS];
UA_Double           pressureValues[MAX_MEASUREMENTS];
size_t              measurementsSubscriber = 0;
/* Array to store timestamp */
struct timespec     subscribeTimestamp[MAX_MEASUREMENTS];

/* Thread for subscriber */
pthread_t           subthreadID;
/* Variable for PubSub connection creation */
UA_NodeId           connectionIdentSubscriber;
struct timespec     dataReceiveTime;

/* Thread for user application*/
pthread_t           userApplicationThreadID;

typedef struct {
UA_Server*                   ServerRun;
} serverConfigStruct;

/* Structure to define thread parameters */
typedef struct {
UA_Server*                   server;
void*                        data;
UA_ServerCallback            callback;
UA_Duration                  interval_ms;
UA_UInt64*                   callbackId;
} threadArg;

/* Subscriber thread routine */
void *subscriber(void *arg);
/* User application thread routine */
void *userApplicationSub(void *arg);
/* To create multi-threads */
static pthread_t threadCreation(UA_Int32 threadPriority, UA_Int32 coreAffinity, void *(*thread) (void *),
                                char *applicationName, void *serverConfig);

/* Stop signal */
static void stopHandler(int sign) {
    UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_SERVER, "received ctrl-c");
    running = UA_FALSE;
}

Nanosecond field handling

Nanosecond field in timespec is checked for overflowing and one second is added to seconds field and nanosecond field is set to zero

    while (timeSpecValue->tv_nsec > (SECONDS -1)) {
        /* Move to next second and remove it from ns field */
        timeSpecValue->tv_sec  += SECONDS_INCREMENT;
        timeSpecValue->tv_nsec -= SECONDS;
    }

}

Custom callback handling

Custom callback thread handling overwrites the default timer based callback function with the custom (user-specified) callback interval.

/* Add a callback for cyclic repetition */
static UA_StatusCode
addPubSubApplicationCallback(UA_Server *server, UA_NodeId identifier, UA_ServerCallback callback,
                             void *data, UA_Double interval_ms,
                             UA_DateTime *baseTime, UA_TimerPolicy timerPolicy,
                             UA_UInt64 *callbackId) {
    /* Initialize arguments required for the thread to run */
    threadArg *threadArguments = (threadArg *) UA_malloc(sizeof(threadArg));

    /* Pass the value required for the threads */
    threadArguments->server      = server;
    threadArguments->data        = data;
    threadArguments->callback    = callback;
    threadArguments->interval_ms = interval_ms;
    threadArguments->callbackId  = callbackId;
    /* Create the subscriber thread with the required priority and core affinity */
    char threadNameSub[11] = "Subscriber";
    subthreadID            = threadCreation(subPriority, pubSubCore, subscriber, threadNameSub, threadArguments);
    return UA_STATUSCODE_GOOD;
}

static UA_StatusCode
changePubSubApplicationCallback(UA_Server *server, UA_NodeId identifier, UA_UInt64 callbackId,
                                UA_Double interval_ms, UA_DateTime *baseTime, UA_TimerPolicy timerPolicy) {
    /* Callback interval need not be modified as it is thread based implementation.
     * The thread uses nanosleep for calculating cycle time and modification in
     * nanosleep value changes cycle time */
    return UA_STATUSCODE_GOOD;
}

/* Remove the callback added for cyclic repetition */
static void
removePubSubApplicationCallback(UA_Server *server, UA_NodeId identifier, UA_UInt64 callbackId) {
    if(callbackId && (pthread_join((pthread_t)callbackId, NULL) != 0))
        UA_LOG_WARNING(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
                       "Pthread Join Failed thread: %lu\n", (long unsigned)callbackId);
}

External data source handling

If the external data source is written over the information model, the externalDataWriteCallback will be triggered. The user has to take care and assure that the write leads not to synchronization issues and race conditions.

static UA_StatusCode
externalDataWriteCallback(UA_Server *server, const UA_NodeId *sessionId,
                          void *sessionContext, const UA_NodeId *nodeId,
                          void *nodeContext, const UA_NumericRange *range,
                          const UA_DataValue *data){
    //node values are updated by using variables in the memory
    //UA_Server_write is not used for updating node values.
    return UA_STATUSCODE_GOOD;
}

static UA_StatusCode
externalDataReadNotificationCallback(UA_Server *server, const UA_NodeId *sessionId,
                                     void *sessionContext, const UA_NodeId *nodeid,
                                     void *nodeContext, const UA_NumericRange *range){
    //allow read without any preparation
    return UA_STATUSCODE_GOOD;
}

Subscriber Connection Creation

Create Subscriber connection for the Subscriber thread

static void
addPubSubConnectionSubscriber(UA_Server *server, UA_NetworkAddressUrlDataType *networkAddressUrlSubscriber){
    UA_StatusCode    retval                                 = UA_STATUSCODE_GOOD;
    /* Details about the connection configuration and handling are located
     * in the pubsub connection tutorial */
    UA_PubSubConnectionConfig connectionConfig;
    memset(&connectionConfig, 0, sizeof(connectionConfig));
    connectionConfig.name                                   = UA_STRING("Subscriber Connection");
    connectionConfig.enabled                                = UA_TRUE;
    UA_NetworkAddressUrlDataType networkAddressUrlsubscribe = *networkAddressUrlSubscriber;
    connectionConfig.transportProfileUri                    = UA_STRING(ETH_TRANSPORT_PROFILE);
    UA_Variant_setScalar(&connectionConfig.address, &networkAddressUrlsubscribe, &UA_TYPES[UA_TYPES_NETWORKADDRESSURLDATATYPE]);
    connectionConfig.publisherIdType                        = UA_PUBLISHERIDTYPE_UINT32;
    connectionConfig.publisherId.uint32                     = UA_UInt32_random();
    retval |= UA_Server_addPubSubConnection(server, &connectionConfig, &connectionIdentSubscriber);
    if (retval == UA_STATUSCODE_GOOD)
         UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_SERVER,"The PubSub Connection was created successfully!");
}

ReaderGroup

ReaderGroup is used to group a list of DataSetReaders. All ReaderGroups are created within a PubSubConnection and automatically deleted if the connection is removed.

/* Add ReaderGroup to the created connection */
static void
addReaderGroup(UA_Server *server) {
    if (server == NULL) {
        return;
    }

    UA_ReaderGroupConfig     readerGroupConfig;
    memset (&readerGroupConfig, 0, sizeof(UA_ReaderGroupConfig));
    readerGroupConfig.name   = UA_STRING("ReaderGroup1");
    readerGroupConfig.rtLevel = UA_PUBSUB_RT_FIXED_SIZE;
    readerGroupConfig.pubsubManagerCallback.addCustomCallback = addPubSubApplicationCallback;
    readerGroupConfig.pubsubManagerCallback.changeCustomCallback = changePubSubApplicationCallback;
    readerGroupConfig.pubsubManagerCallback.removeCustomCallback = removePubSubApplicationCallback;
    UA_Server_addReaderGroup(server, connectionIdentSubscriber, &readerGroupConfig,
                             &readerGroupIdentifier);
}

SubscribedDataSet

Set SubscribedDataSet type to TargetVariables data type Add SubscriberCounter variable to the DataSetReader

static void addSubscribedVariables (UA_Server *server) {
    if (server == NULL) {
        return;
    }

    UA_FieldTargetVariable *targetVars = (UA_FieldTargetVariable*)
        UA_calloc(2, sizeof(UA_FieldTargetVariable));

    subCounterData = UA_UInt64_new();
    *subCounterData = 0;
    subDataValueRT = UA_DataValue_new();
    UA_Variant_setScalar(&subDataValueRT->value, subCounterData, &UA_TYPES[UA_TYPES_UINT64]);
    subDataValueRT->hasValue = UA_TRUE;
    /* Set the value backend of the above create node to 'external value source' */
    UA_ValueBackend valueBackend;
    valueBackend.backendType = UA_VALUEBACKENDTYPE_EXTERNAL;
    valueBackend.backend.external.value = &subDataValueRT;
    valueBackend.backend.external.callback.userWrite = externalDataWriteCallback;
    valueBackend.backend.external.callback.notificationRead = externalDataReadNotificationCallback;
    /* If user need to change the nodeid of the custom nodes in the application then it must be
     * changed inside the xml and .csv file inside examples\pubsub_realtime\nodeset\*/
     /* The nodeid of the Custom node SubscriberCounterVariable is 2005 which is used below */
    UA_Server_setVariableNode_valueBackend(server, UA_NODEID_NUMERIC(nsIdx, 2005), valueBackend);
    UA_FieldTargetDataType_init(&targetVars[0].targetVariable);
    targetVars[0].targetVariable.attributeId  = UA_ATTRIBUTEID_VALUE;
    targetVars[0].targetVariable.targetNodeId = UA_NODEID_NUMERIC(nsIdx, 2005);

    pressureData = UA_Double_new();
    *pressureData = 0;
    pressureValueRT = UA_DataValue_new();
    UA_Variant_setScalar(&pressureValueRT->value, pressureData, &UA_TYPES[UA_TYPES_DOUBLE]);
    pressureValueRT->hasValue = UA_TRUE;
    /* Set the value backend of the above create node to 'external value source' */
    UA_ValueBackend valueBackend1;
    valueBackend1.backendType = UA_VALUEBACKENDTYPE_EXTERNAL;
    valueBackend1.backend.external.value = &pressureValueRT;
    valueBackend1.backend.external.callback.userWrite = externalDataWriteCallback;
    valueBackend1.backend.external.callback.notificationRead = externalDataReadNotificationCallback;
    /* The nodeid of the Custom node Pressure is 2006 which is used below */
    UA_Server_setVariableNode_valueBackend(server, UA_NODEID_NUMERIC(nsIdx, 2006), valueBackend1);
    UA_FieldTargetDataType_init(&targetVars[1].targetVariable);
    targetVars[1].targetVariable.attributeId  = UA_ATTRIBUTEID_VALUE;
    targetVars[1].targetVariable.targetNodeId = UA_NODEID_NUMERIC(nsIdx, 2006);

    /* Set the subscribed data to TargetVariable type */
    readerConfig.subscribedDataSetType = UA_PUBSUB_SDS_TARGET;
    readerConfig.subscribedDataSet.subscribedDataSetTarget.targetVariables = targetVars;
    readerConfig.subscribedDataSet.subscribedDataSetTarget.targetVariablesSize = 2;
}

DataSetReader

DataSetReader can receive NetworkMessages with the DataSetMessage of interest sent by the Publisher. DataSetReader provides the configuration necessary to receive and process DataSetMessages on the Subscriber side. DataSetReader must be linked with a SubscribedDataSet and be contained within a ReaderGroup.

/* Add DataSetReader to the ReaderGroup */
static void
addDataSetReader(UA_Server *server) {
    if (server == NULL) {
        return;
    }

    memset (&readerConfig, 0, sizeof(UA_DataSetReaderConfig));
    readerConfig.name                 = UA_STRING("DataSet Reader 1");
    UA_UInt16 publisherIdentifier     = PUBLISHER_ID_SUB;
    readerConfig.publisherId.type     = &UA_TYPES[UA_TYPES_UINT16];
    readerConfig.publisherId.data     = &publisherIdentifier;
    readerConfig.writerGroupId        = WRITER_GROUP_ID_SUB;
    readerConfig.dataSetWriterId      = DATA_SET_WRITER_ID_SUB;

    readerConfig.messageSettings.encoding = UA_EXTENSIONOBJECT_DECODED;
    readerConfig.messageSettings.content.decoded.type = &UA_TYPES[UA_TYPES_UADPDATASETREADERMESSAGEDATATYPE];
    UA_UadpDataSetReaderMessageDataType *dataSetReaderMessage = UA_UadpDataSetReaderMessageDataType_new();
    dataSetReaderMessage->networkMessageContentMask           = (UA_UadpNetworkMessageContentMask)(UA_UADPNETWORKMESSAGECONTENTMASK_PUBLISHERID |
                                                                 (UA_UadpNetworkMessageContentMask)UA_UADPNETWORKMESSAGECONTENTMASK_GROUPHEADER |
                                                                 (UA_UadpNetworkMessageContentMask)UA_UADPNETWORKMESSAGECONTENTMASK_WRITERGROUPID |
                                                                 (UA_UadpNetworkMessageContentMask)UA_UADPNETWORKMESSAGECONTENTMASK_PAYLOADHEADER);
    readerConfig.messageSettings.content.decoded.data = dataSetReaderMessage;

    /* Setting up Meta data configuration in DataSetReader */
    UA_DataSetMetaDataType *pMetaData = &readerConfig.dataSetMetaData;
    /* FilltestMetadata function in subscriber implementation */
    UA_DataSetMetaDataType_init(pMetaData);
    pMetaData->name                   = UA_STRING ("DataSet Test");
    /* Static definition of number of fields size to 1 to create one
       targetVariable */
    pMetaData->fieldsSize             =  2;
    pMetaData->fields                 = (UA_FieldMetaData*)UA_Array_new (pMetaData->fieldsSize,
                                                                         &UA_TYPES[UA_TYPES_FIELDMETADATA]);

    /* Unsigned Integer DataType */
    UA_FieldMetaData_init (&pMetaData->fields[0]);
    UA_NodeId_copy (&UA_TYPES[UA_TYPES_UINT64].typeId,
                    &pMetaData->fields[0].dataType);
    pMetaData->fields[0].builtInType = UA_NS0ID_UINT64;
    pMetaData->fields[0].valueRank   = -1; /* scalar */

    /* Double DataType */
    UA_FieldMetaData_init (&pMetaData->fields[1]);
    UA_NodeId_copy (&UA_TYPES[UA_TYPES_DOUBLE].typeId,
                    &pMetaData->fields[1].dataType);
    pMetaData->fields[1].builtInType = UA_NS0ID_DOUBLE;
    pMetaData->fields[1].valueRank   = -1;  /* scalar */

    /* Setup Target Variables in DSR config */
    addSubscribedVariables(server);

    /* Setting up Meta data configuration in DataSetReader */
    UA_Server_addDataSetReader(server, readerGroupIdentifier, &readerConfig,
                               &readerIdentifier);

    UA_free(readerConfig.subscribedDataSet.subscribedDataSetTarget.targetVariables);
    UA_free(readerConfig.dataSetMetaData.fields);
    UA_UadpDataSetReaderMessageDataType_delete(dataSetReaderMessage);
}

Subscribed data handling

The subscribed data is updated in the array using this function Subscribed data handling**

static void
updateMeasurementsSubscriber(struct timespec receive_time, UA_UInt64 counterValue, UA_Double pressureValue) {
    subscribeTimestamp[measurementsSubscriber]     = receive_time;
    subscribeCounterValue[measurementsSubscriber]  = counterValue;
    pressureValues[measurementsSubscriber]         = pressureValue;
    measurementsSubscriber++;
}

Subscriber thread routine

Subscriber thread will wakeup during the start of cycle at 250us interval and check if the packets are received. The subscriber function is the routine used by the subscriber thread.

void *subscriber(void *arg) {
    UA_Server*        server;
    UA_ReaderGroup*   currentReaderGroup;
    UA_ServerCallback subCallback;
    struct timespec   nextnanosleeptimeSub;

    threadArg *threadArgumentsSubscriber = (threadArg *)arg;
    server                               = threadArgumentsSubscriber->server;
    subCallback                          = threadArgumentsSubscriber->callback;
    currentReaderGroup                   = (UA_ReaderGroup *)threadArgumentsSubscriber->data;

    /* Get current time and compute the next nanosleeptime */
    clock_gettime(CLOCKID, &nextnanosleeptimeSub);
    /* Variable to nano Sleep until 1ms before a 1 second boundary */
    nextnanosleeptimeSub.tv_sec         += SECONDS_SLEEP;
    nextnanosleeptimeSub.tv_nsec         = (__syscall_slong_t)(cycleTimeMsec * subWakeupPercentage * MILLI_SECONDS);
    nanoSecondFieldConversion(&nextnanosleeptimeSub);
    while (running) {
        clock_nanosleep(CLOCKID, TIMER_ABSTIME, &nextnanosleeptimeSub, NULL);
        /* Read subscribed data from the SubscriberCounter variable */
        subCallback(server, currentReaderGroup);
        nextnanosleeptimeSub.tv_nsec += (__syscall_slong_t)(cycleTimeMsec * MILLI_SECONDS);
        nanoSecondFieldConversion(&nextnanosleeptimeSub);
    }

    UA_free(threadArgumentsSubscriber);

    return (void*)NULL;
}

UserApplication thread routine

The userapplication thread will wakeup at 30% of cycle time and handles the userdata in the Information Model. This thread is used to write the counterdata that is subscribed by the Subscriber thread in a csv.

void *userApplicationSub(void *arg) {
    struct timespec nextnanosleeptimeUserApplication;
    /* Get current time and compute the next nanosleeptime */
    clock_gettime(CLOCKID, &nextnanosleeptimeUserApplication);
    /* Variable to nano Sleep until 1ms before a 1 second boundary */
    nextnanosleeptimeUserApplication.tv_sec                      += SECONDS_SLEEP;
    nextnanosleeptimeUserApplication.tv_nsec                      = (__syscall_slong_t)(cycleTimeMsec * userAppWakeupPercentage * MILLI_SECONDS);
    nanoSecondFieldConversion(&nextnanosleeptimeUserApplication);

    while (running) {
        clock_nanosleep(CLOCKID, TIMER_ABSTIME, &nextnanosleeptimeUserApplication, NULL);
        clock_gettime(CLOCKID, &dataReceiveTime);
        if ((fileWrite == UA_TRUE) || (consolePrint == UA_TRUE)) {
            if (*subCounterData > 0)
                updateMeasurementsSubscriber(dataReceiveTime, *subCounterData, *pressureData);
        }
        nextnanosleeptimeUserApplication.tv_nsec += (__syscall_slong_t)(cycleTimeMsec * MILLI_SECONDS);
        nanoSecondFieldConversion(&nextnanosleeptimeUserApplication);
    }

    return (void*)NULL;
}

Thread creation

The threadcreation functionality creates thread with given threadpriority, coreaffinity. The function returns the threadID of the newly created thread.

static pthread_t threadCreation(UA_Int32 threadPriority, UA_Int32 coreAffinity, void *(*thread) (void *), \
                                char *applicationName, void *serverConfig){

    /* Core affinity set */
    cpu_set_t           cpuset;
    pthread_t           threadID;
    struct sched_param  schedParam;
    UA_Int32         returnValue         = 0;
    UA_Int32         errorSetAffinity    = 0;
    /* Return the ID for thread */
    threadID = pthread_self();
    schedParam.sched_priority = threadPriority;
    returnValue = pthread_setschedparam(threadID, SCHED_FIFO, &schedParam);
    if (returnValue != 0) {
        UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,"pthread_setschedparam: failed\n");
        exit(1);
    }
    UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,\
                "\npthread_setschedparam:%s Thread priority is %d \n", \
                applicationName, schedParam.sched_priority);
    CPU_ZERO(&cpuset);
    CPU_SET((size_t)coreAffinity, &cpuset);
    errorSetAffinity = pthread_setaffinity_np(threadID, sizeof(cpu_set_t), &cpuset);
    if (errorSetAffinity) {
        fprintf(stderr, "pthread_setaffinity_np: %s\n", strerror(errorSetAffinity));
        exit(1);
    }

    returnValue = pthread_create(&threadID, NULL, thread, serverConfig);
    if (returnValue != 0) {
        UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,":%s Cannot create thread\n", applicationName);
    }

    if (CPU_ISSET((size_t)coreAffinity, &cpuset)) {
        UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,"%s CPU CORE: %d\n", applicationName, coreAffinity);
    }

   return threadID;

}

Usage function

The usage function gives the list of options that can be configured in the application.

./bin/examples/pubsub_nodeset_rt_subscriber -h gives the list of options for running the application.

static void usage(char *appname)
{
    fprintf(stderr,
        "\n"
        "usage: %s [options]\n"
        "\n"
        " -i [name]     use network interface 'name'\n"
        " -C [num]      cycle time in milli seconds (default %lf)\n"
        " -p            Do you need to print the data in console output\n"
        " -P [num]      Publisher priority value (default %d)\n"
        " -U [num]      User application priority value (default %d)\n"
        " -c [num]      run on CPU for publisher'num'(default %d)\n"
        " -u [num]      run on CPU for userApplication'num'(default %d)\n"
        " -m [mac_addr] ToDO:dst MAC address\n"
        " -h            prints this message and exits\n"
        "\n",
        appname, DEFAULT_CYCLE_TIME, DEFAULT_SUB_SCHED_PRIORITY, \
        DEFAULT_USERAPPLICATION_SCHED_PRIORITY, DEFAULT_PUBSUB_CORE, DEFAULT_USER_APP_CORE);
}

Main Server code

The main function contains subscriber threads running

int main(int argc, char **argv) {
    signal(SIGINT, stopHandler);
    signal(SIGTERM, stopHandler);

    UA_Int32         returnValue         = 0;
    char             *interface          = NULL;
    char             *progname;
    UA_Int32         argInputs           = -1;
    UA_StatusCode    retval              = UA_STATUSCODE_GOOD;
    UA_Server       *server              = UA_Server_new();
    UA_ServerConfig *config              = UA_Server_getConfig(server);
    pthread_t        userThreadID;
    UA_ServerConfig_setMinimal(config, PORT_NUMBER, NULL);

    /* Files namespace_example_subscriber_generated.h and namespace_example_subscriber_generated.c are created from
     * subDataModel.xml in the /src_generated directory by CMake */
    /* Loading the user created variables into the information model from the generated .c and .h files */
    if(namespace_example_subscriber_generated(server) != UA_STATUSCODE_GOOD) {
        UA_LOG_ERROR(UA_Log_Stdout, UA_LOGCATEGORY_SERVER, "Could not add the example nodeset. "
        "Check previous output for any error.");
    }
    else
    {
        nsIdx = UA_Server_addNamespace(server, "http://yourorganisation.org/test/");
    }
    UA_NetworkAddressUrlDataType networkAddressUrlSub;
    /* For more information run ./bin/examples/pubsub_nodeset_rt_subscriber -h */
    /* Process the command line arguments */
    progname = strrchr(argv[0], '/');
    progname = progname ? 1 + progname : argv[0];
    while (EOF != (argInputs = getopt(argc, argv, "i:C:f:ps:P:U:c:u:tm:h:"))) {
        switch (argInputs) {
            case 'i':
                interface = optarg;
                break;
            case 'C':
                cycleTimeMsec = atof(optarg);
                break;
            case 'f':
                fileName = optarg;
                fileWrite = UA_TRUE;
                fpSubscriber = fopen(fileName, "w");
                break;
            case 'p':
                consolePrint = UA_TRUE;
                break;
            case 'P':
                subPriority = atoi(optarg);
                break;
            case 'U':
                userAppPriority = atoi(optarg);
                break;
            case 'c':
                pubSubCore = atoi(optarg);
                break;
            case 'u':
                userAppCore = atoi(optarg);
                break;
            case 'm':
                /*ToDo:Need to handle for mac address*/
                break;
            case 'h':
                usage(progname);
                return -1;
            case '?':
                usage(progname);
                return -1;
        }
    }

    if (cycleTimeMsec < 0.125) {
        UA_LOG_ERROR(UA_Log_Stdout, UA_LOGCATEGORY_SERVER, "%f Bad cycle time", cycleTimeMsec);
        usage(progname);
        return -1;
    }

    if (!interface) {
        UA_LOG_ERROR(UA_Log_Stdout, UA_LOGCATEGORY_SERVER, "Need a network interface to run");
        usage(progname);
        UA_Server_delete(server);
        return 0;
    }
    networkAddressUrlSub.networkInterface = UA_STRING(interface);
    networkAddressUrlSub.url              = UA_STRING(SUBSCRIBING_MAC_ADDRESS);

    addPubSubConnectionSubscriber(server, &networkAddressUrlSub);
    addReaderGroup(server);
    addDataSetReader(server);
    UA_Server_freezeReaderGroupConfiguration(server, readerGroupIdentifier);
    UA_Server_setReaderGroupOperational(server, readerGroupIdentifier);
    serverConfigStruct *serverConfig;
    serverConfig            = (serverConfigStruct*)UA_malloc(sizeof(serverConfigStruct));
    serverConfig->ServerRun = server;

    char threadNameUserApplication[22] = "UserApplicationSub";
    userThreadID                       = threadCreation(userAppPriority, userAppCore, userApplicationSub, threadNameUserApplication, serverConfig);

    retval |= UA_Server_run(server, &running);

    UA_Server_unfreezeReaderGroupConfiguration(server, readerGroupIdentifier);
    returnValue = pthread_join(subthreadID, NULL);
    if (returnValue != 0) {
        UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,"\nPthread Join Failed for subscriber thread:%d\n", returnValue);
    }
    returnValue = pthread_join(userThreadID, NULL);
    if (returnValue != 0) {
        UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,"\nPthread Join Failed for User thread:%d\n", returnValue);
    }
    if (fileWrite == UA_TRUE) {
        /* Write the subscribed data in the file */
        size_t subLoopVariable               = 0;
        for (subLoopVariable = 0; subLoopVariable < measurementsSubscriber;
             subLoopVariable++) {
             fprintf(fpSubscriber, "%lu,%ld.%09ld,%lf\n",
                     (long unsigned)subscribeCounterValue[subLoopVariable],
                     subscribeTimestamp[subLoopVariable].tv_sec,
                     subscribeTimestamp[subLoopVariable].tv_nsec,
                     pressureValues[subLoopVariable]);
        }
        fclose(fpSubscriber);
    }
    if (consolePrint == UA_TRUE) {
        size_t subLoopVariable               = 0;
        for (subLoopVariable = 0; subLoopVariable < measurementsSubscriber;
             subLoopVariable++) {
             fprintf(fpSubscriber, "%lu,%ld.%09ld,%lf\n",
                     (long unsigned)subscribeCounterValue[subLoopVariable],
                     subscribeTimestamp[subLoopVariable].tv_sec,
                     subscribeTimestamp[subLoopVariable].tv_nsec,
                     pressureValues[subLoopVariable]);
        }
    }
    UA_Server_delete(server);
    UA_free(serverConfig);
    UA_free(subCounterData);
    /* Free external data source */
    UA_free(subDataValueRT);
    UA_free(pressureData);
    /* Free external data source */
    UA_free(pressureValueRT);
    return (int)retval;
}