Aperiodic Transmission

In order to transmit data using a SAP port you must:

• Create the transmission virtual link using the mxfA664VlCreate() function.
• Create the port using the mxfA664PortCreate() function.
• The messages to be sent must be stored in a MXF_A664_DATAREC structure. The destination IP address and port number are written into the MXF_A664_DATAREC.type.Sap.ipAddress and MXF_A664_DATAREC.type.Sap.udpPort fields.
• Start transmission using the mxfA664TxPeriodicWrite() function with the port handle. No timing option is available, the transmission timing is controlled by the VL BAG scheduler.

Example

ar664_aperiodicSap.c
The code snippets below demonstrate the basic steps needed to setup a SAP port transmission.

...

// Create the transmission (TX) virtual link
if (!rc)
{
   memset(&vlParam, 0, sizeof(MXF_A664_VL_PARAM));
   vlParam.direction = MXF_A664_VL_DIR_TX;
   vlParam.VLId = vlid;
   vlParam.frameType = MXF_A664_FRAME_TYPE_ARINC664;
   vlParam.frameSizeMax = 512;
   vlParam.dir.Tx.subVlNumber = 1;
   vlParam.dir.Tx.bag = 1 * 1000 * 1000;  // 1ms
   vlParam.dir.Tx.netSelection = MXF_A664_NETSELECT_ALL;
   vlParam.dir.Tx.Ede.enable = FALSE;
   vlParam.dir.Tx.subVl[0].bufferSize = vlParam.frameSizeMax;
   vlParam.dir.Tx.subVl[0].maxBuffers = maxTxRecords;

   rc = mxfA664VlCreate(phyChn, &vlParam, &vlTx);
}

// Create the transmission SAP port
if (!rc)
{
   inet_pton(AF_INET, DST_IP_ADRS, &srcIpAdrs);
   inet_pton(AF_INET, SRC_IP_ADRS, &dstIpAdrs);
   dstIpAdrs = ntohl(dstIpAdrs);

   memset(&portParam, 0, sizeof(MXF_A664_PORT_PARAM));
   portParam.portType = MXF_A664_PORT_TYPE_SAP;
   portParam.family = MXF_A664_PORT_FAMILY_IPV4;
   portParam.mode = MXF_A664_PORT_MODE_QUEUING;
   portParam.type.SAP.srcAddress.port = SRC_UDP_PORT;
   portParam.type.SAP.srcAddress.version.IPv4.address = ntohl(srcIpAdrs);

   rc = mxfA664PortCreate(vlTx, &portParam, &portTx);
}

...               

// Build the Transmit Records
for (recordIdx = 0, data = txRec; recordIdx < maxTxRecords && !rc; recordIdx++)
{
   data->control = 0;
   data->dataSize = TEST_DATASIZE;
   data->repeatCount = 1;

  // Index to the base address (LSB byte) for sending 
  // to a range of host addresses [10.0.0.111 ..  10.0.0.127]. 
   data->type.Sap.ipAddress = dstIpAdrs + recordIdx;
   data->type.Sap.udpPort = DST_UDP_PORT;

   for (dataIdx = 0; dataIdx < TEST_DATASIZE; dataIdx++)
      data->data[dataIdx] = (uint8)((dataIdx + ((recordIdx*TEST_DATASIZE) & 0xff)));
   rc = mxfA664NextDataRecordPtrGet(data, &data);
}

// Transmit the data
if (!rc)
{
   rc = mxfA664TxAperiodicWrite(portTx, MXF_TXAPERIODIC_FLAG_DEFAULT, 0, maxTxRecords, txRec, &count);
   printf("%llu frames transmitted\n\n", count);
   // Wait for complete transmission
   mxfSleep(500);
}

...

if (!rc)
   rc = mxfA664PortRelease(portTx);

...