heartbeat.c shows how to configure and handle the heartbeat feature.

/*=================================================================================
Hearbeat example
This is a VAPI based code implementation of a function which can be used to enable 
the heartbeat feature of the MSP and handle the heartbeat indications.
=================================================================================*/
#include <stdio.h>
#include <vapi.h>
#include <msp.h>
#include <comcerto-stat-combined-voice-types.h>
#include <ut.h>

/*define one timer per device*/
STimer t_heart_beat_timer;

/*In the application event handler 
implement a handler for the HEARTBEAT indication.*/
/*
msp_indication_handler()
{
...
        
        case eVAPI_UNDEFINED_EVENT:
                this_event = (SUndefinedEventParams *) pvData;


                // check if we received an indication from MSP
                // If yes take the appropriated handling
                if (this_event->ucCmdType != CMD_TYPE_INDICATION)
                        return;

                // Device level events
                if (this_event->ucLevel == CMD_LEVEL_DEVICE)
                {
                        switch(this_event->usFnCode)
                        {
                        case FC_DEVICE_STATUS:
                                heartbeat_info = this_event->ausParams[2];

                                //if the heartbeat is receive with error print out some messages
                                if ((heartbeat_info & 0xFB) != 0xFB)
                                        printf("   (%04x)  !ERR! HEARTBEAT FAILURE (0x%02x)", this_event->ausParams[1], heartbeat_info);

                                
                                //restart the heartbeat timer
                                restartHeartBeatTimer(this_event->ID.DevId);
                                return;
                                break;

                        default:
                                break;
                        }
                }
...
}
*/

/*This function can be called once the device is configured (TDM,IP,MAC, ...)*/
VSTATUS start_msp_heartbeat(int device_id, unsigned int heartbeat_period, unsigned int gpio_period, unsigned int gpio_port)
{
        VSTATUS result;
        void *message;
        
        U32 response_len = DEFAULT_FIFO_MAX_SIZE;
        U8 device_response [DEFAULT_FIFO_MAX_SIZE];

        if(heartbeat_period > 10)
                return VAPI_ERR_INVALID_PARAM;

        message = VAPI_AllocateMessage(DEFAULT_FIFO_MAX_SIZE);

        if(message == NULL)
                return VAPI_ERR_NOMEM;

        result = VAPI_SetMessage(message, CMD_CLASS_CONF_DEVICE, CMD_TYPE_CONF_CHANGE, FC_DEVICE_STATUS,        
                                4,                              /* 4 parameters */
                                heartbeat_period,               /* P1: Heartbeat period in seconds, Max = 10s */
                                gpio_period,                    /* P2: GPIO toggle period in seconds, Max = 10s */
                                gpio_port,                      /* P3: GPIO port select */
                                0x0000                          /* P4: Reserved */
                                );

        if(result == SUCCESS)
                result = VAPI_SendDeviceMessage(device_id, (SMsg *)message, NULL, device_response, &response_len);
        

        VAPI_FreeMessage(message);

        return result;
}

/*This function is called when no heartbeat indication has been receive for a period set by start_msp_heartbeat*/
void  heart_beat_timeout()
{
        UT_TimerStop(&t_heart_beat_timer);

        printf("heart_beat_timeout!! Coredump process would be started!\n");

        return;
}

/*This function is called to start/resert the heartbeat timer*/
/*The heartbeat period must be < to timer TIMEOUT see below*/
#define MSP_HEARTBEAT_PERIOD    1
void  restart_heart_beatTimer()
{
        UT_TimerStop(&t_heart_beat_timer);
        UT_TimerStart(&t_heart_beat_timer, MSP_HEARTBEAT_PERIOD, (PFNTimerFunc)heart_beat_timeout, NULL);
}