Basic Sampling

The way to setup a basic sampling receive application is as follows:

• A receive channel must be obtained using the mxfModuleChannelGet() or mxfModuleChannelAllGet() functions, and using the MXF_SCLASS_RXSAMPLING_SRV subclass.
• The sampling buffer must be allocated using the mxfRxSamplingBufferAlloc() function.
• A sampling kill time can be set with the mxfRxSamplingKilltimeSet() function to allow the invalidation of the last reception if the data is too old.
• Start the sampling using the mxfRxSamplingStart() function.
• Sampling read can be performed by using the mxfMIL1553RxSamplingRead() or mxfMIL1553RxSamplingSingleRead() functions, and the data received decoded using the mxfMIL1553SamplingRecordDecompose() function.

The MXF_MIL1553_SAMPREC structure must be used for reading MIL-1553 messages with sampling service.

Example

mil1553_bc_buserror_trigger.c

HMXF_SERVER server;
HMXF_CHANNEL bm;
HMXF_BUFFER samp1553Buffer;
uint32 rc;
void*                   rxData=0;
MXF_MIL1553_SAMPREC *sampRec1553;
uint64 msgCount, byteCount;     
uint64                  rxRec;
uint64                  loop=0;
uint32                  data;
uint64 rxDataSize = 10*1024;

   ...

   // Sets timebase to RTC nsec
   if(!rc)
      rc = mxfSystemTimeBaseSet(server, MXF_TIMEBASE_DEVICE_NSEC);

   // Allocates 10KB buffer for 1553 sampling data
   if(!rc)
      rc = mxfRxSamplingBufferAlloc(bm, rxDataSize, &samp1553Buffer, NULL);

   if(!rc)
      rc = mxfRxSamplingKilltimeSet(samp1553Buffer, 2000000000);

   // Host allocation
   if(!rc)
   {
      rxData = malloc(rxDataSize);
      if(!rxData)
         rc = MAXT_ERROR_MEM;
   }      

   ...

   // Starts BM sampling
   if(!rc)
      rc = mxfRxSamplingStart(samp1553Buffer);

   printf("Sampling started for 5 seconds, waiting...\n");
   mxfSleep(5000);

   // Reads and displays received messages
   if(!rc)
   {         
      rc = mxfMIL1553RxSamplingRead(samp1553Buffer, 0, 0, rxDataSize, &msgCount, &byteCount, rxData);
      sampRec1553 = (MXF_MIL1553_SAMPREC*)rxData;
      for(rxRec=0; !rc && rxRec<msgCount; rxRec++)
      {
         printf("%012llu ", sampRec1553->timeTag);
         printf("%03u  ", sampRec1553->rate);
         printf("%08X ", sampRec1553->control);
         printf("%04u ", (sampRec1553->dataSize/2)-1);
         for(data=0; data < min(5, sampRec1553->dataSize/2); data++)
         {
            printf("%04X ", sampRec1553->data[data]);
         }
         printf("\n\r");
         // Gets next msg
         mxfMIL1553NextSamplingRecordPtrGet(sampRec1553, &sampRec1553);
      }
   }

   // Stops sampling
   if(!rc)
      rc = mxfRxSamplingStop(samp1553Buffer);

   ...