Acquisition Service

The RT channels on MIL-1553 modules support this service.

The acquisition service on a RT channel is useful to acquire the status and data that are sent from the BC and other RTs to the RT, but without resorting to the use of the BM channel.

With RT channels, this service will use the message mode. The monitor mode is an attribute changed on the BM channel, so in this case, the BM channel monitor mode must be set to either string or message mode (see KMXF_MIL1553_BM_MODE attribute). If the BM monitor mode is set to word mode, RT channels will receive nothing. Acquisition with RT channels work differently than with BM channels. The data transmitted by the RT is not received by this RT.

The following possibilities will be received by RT channel:

• RXCmd/Data
• TXCmd
• RXCmd/TXCmd/TXStatus/Data (receiver side)
• RXCmd/TXCmd/RXStatus (transmitter side)
• ModeCode/Status
• TXModeCode/Status/Data (Data is optional)
• RXModeCode/Data/Status (Data is optional)

Note

No-response messages are not received by RT channels.
TX Periodic Update Message service must be active on the RT to receive with this RT channel.

Refer to the MXF_MIL1553_DATAREC structure for acquisition data reading.

The same options for acquisition filtering, acquisition with trigger and asynchronous events of BM channels apply to RT channels.

uint32 rc;
HMXF_CHANNEL rt;
HMXF_BUFFER rx=0;
uint32 rxBufferSize=0;
MXF_MIL1553_DATAREC* rxBuffer=NULL;
MXF_MIL1553_DATAREC* rxRec1553;
uint64   rxAcqStatus;
uint64   msgCount;
uint64   byteCount;
uint64   rxRec;
uint32   loop=0;

   ...

   // Allocates buffer for Rx data
   if(!rc)
   {
      rxBufferSize = 64*4096;

      // Flex1553 allocation
      rc = mxfRxAcqBufferAlloc(rt, rxBufferSize, &rx, NULL);

      // Host allocation
      if(!rc)
      {
         rxBuffer = (MXF_MIL1553_DATAREC*)malloc(rxBufferSize);
         if(!rxBuffer)
            rc = MAXT_ERROR_MEM;
      }
   }

   // Starts RT acquisition
   if(!rc)
      rc = mxfRxAcqStart(rx, MXF_RXACQ_FLAG_DEFAULT, 0, 0);

   // Read and display received messages
   if(!rc)
   {
      do
      {  
         rc = mxfMIL1553RxAcqRead(rx, 0, rxBufferSize, &rxAcqStatus, &msgCount, &byteCount, rxBuffer);
         rxRec1553 = rxBuffer;
         for(rxRec=0; rxRec<msgCount && !rc; rxRec++)
         {
            ...

            // Get next msg
            rc = mxfMIL1553NextDataRecordPtrGet(rxRec1553, &rxRec1553);
         }
         mxfSleep(500);
         loop++;
      } while(loop < 200);
   }

   // Stops acquisition
   if(!rc)
      rc = mxfRxAcqStop(rx);

   if (!rc)
      rc = mxfRxAcqClear(rx);            

   ...

mil1553_rt.c