rtIOStreamRecv

Receive data through communication channel

Syntax

errFlg = rtIOStreamRecv(streamID, dest, size, receivedDataSize)

Description

errFlg = rtIOStreamRecv(streamID, dest, size, receivedDataSize) receives data through a communication channel.

Examples

Send and Receive Data from Processor

This code from rtiostreamtest.c shows how to send and receive data from a target processor.

static void blockingIO(int send, unsigned long numMemUnits)
{
    size_t sizeToTransfer = (size_t) numMemUnits; 
    size_t sizeTransferred;
    IOUnit_T * ioPtr = (IOUnit_T *) &buff[0];
    int status;

    if (numMemUnits > BUFFER_SIZE)
    {
        AckCode = stat_notEnoughSpace;
        AckArg0 = BUFFER_SIZE;
        return;
    }

#ifdef HOST_WORD_ADDRESSABLE_TESTING       
   /* map to bytes */
   sizeToTransfer *= MEM_UNIT_BYTES;
#endif

   while (sizeToTransfer > 0) {
      sizeTransferred = 0;
      /* Do the low level call */
      status = send ?
         rtIOStreamSend(streamID, ioPtr, sizeToTransfer, &sizeTransferred) :
         rtIOStreamRecv(streamID, ioPtr, sizeToTransfer, &sizeTransferred);

      if (status != RTIOSTREAM_NO_ERROR) {
         if (AckCode == stat_OK) {
            AckCode = stat_RTIOSTREAM_ERROR;
            AckArg0 = data_counter;
         }
         return;
      }
      else {
         sizeToTransfer -= sizeTransferred;
         ioPtr += sizeTransferred;
      }
   }
}

Input Arguments

streamID — Stream handle

scalar integer

Handle to the stream returned by a previous call to rtIOStreamOpen.

dest — Data destination

void pointer

Pointer to the start of the buffer for received data.

size — Size of data to copy

size_t

Size of data to copy into the destination buffer. For byte-addressable architectures, size is measured in bytes. Some DSP architectures are not byte-addressable. In these cases, size is measured in number of WORDs, where sizeof(WORD) == 1.

receivedDataSize — Size of data received

size_t

Number of units of data received and copied into the buffer dest. If no data is copied, value is zero.

Output Arguments

errFlg — Error flag

0 | -1

If the function runs without errors, it returns zero. Otherwise, it returns -1.

The rtiostream.h file defines these macros:

#define RTIOSTREAM_ERROR (-1)
#define RTIOSTREAM_NO_ERROR (0)

Version History

Introduced in R2009a