Transmission with Absolute Timing

The option MXF_TXAPERIODIC_FLAG_ABSOLUTE_START_TIME is used for starting a transmission at a specific start time in the future.

ar429_aperiodic.c
In this example, the transmission start time is based on the device clock + 100ms in the future, then the records are sent back-to-back.

#define BUFFER_SIZE     4096 // 4KB
#define MAX_TX_RECORDS_TO_TRANSMIT 8

HMXF_SERVER server;
HMXF_DEVICE device;
HMXF_CHANNEL txChannel;
HMXF_BUFFER  txBuffer=0;
MXF_A429_DATAREC *rec429=NULL;
MXF_A429_DATAREC *rec;
uint32 label, sdi, data, ssm, parity;
uint64 currentTime;
uint32 record;
uint64 delay100ms = 100000;
uint32 rc;

   ...

   // Sets timebase to 64-bit microseconds
   if (!rc)
      rc = mxfSystemTimeBaseSet(server, MXF_TIMEBASE_DEVICE_USEC);

   // Allocates Aperiodic TX static buffer for HIGH priority queue
   if (!rc)
      rc = mxfTxAperiodicBufferAlloc(txChannel, MXF_TXAPERIODIC_PRIORITY_HIGH, BUFFER_SIZE, &txBuffer, NULL);

   // Allocates host buffer
   if (!rc)
   {
      rec429 = (MXF_A429_DATAREC*)malloc(BUFFER_SIZE);
      if (!rec429)
         rc = MAXT_ERROR_MEM;
   }

   // Sets the records: ARINC 429 LABEL=006, SDI=1
   rec = rec429;
   for (record=0; record < MAX_TX_RECORDS_TO_TRANSMIT && !rc; record++)
   {
      rec->timeTag = 0;
      rec->control = 0;
      rec->repeatCount = 1;
      rec->reserved = 0;

      label = 6;
      sdi = 1;
      data = record*16;
      ssm = 0;
      parity = VMXF_A429_PARITY_ODD;
      rc = mxfA429ArwCompose(label, sdi, data, ssm, parity, &rec->data);
      if(!rc)
         rc = mxfA429NextDataRecordPtrGet(rec, &rec);
   }

   // Gets the current time
   if(!rc)
      rc = mxfDeviceTimerGet(device, &currentTime);  

    // Transmit the array of records
    if (!rc)
      rc = mxfA429TxAperiodicWrite(txBuffer, MXF_TXAPERIODIC_FLAG_ABSOLUTE_START_TIME, currentTime+delay100ms, MAX_TX_RECORDS_TO_TRANSMIT, rec429);

    if (rec429)
      free(rec429);

   ...