Read Row-Wise

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Read Row-Wise

Reading row-wise is quite simple. The function NMX_Sampling_ReadRow32_1 is called for each sample and provides the data for all sampling elements. The following example shows this visually.

Sampling_ReadRow

According to this example, NMX_Sampling_ReadRow32_1 must be called 9 times. The function/return parameters are as follows:

Function call

ulMaxSamples

pulSamplesCopied

pudSampleNo

1

≥ 6

6

0

2

≥ 6

6

1

3

≥ 6

6

2

4

≥ 6

6

3

5

≥ 6

6

4

6

≥ 6

6

5

7

≥ 6

6

6

8

≥ 6

6

7

9

≥ 6

6

8

 

C / C++


// ###-> Get Number of Sampling elements. This could be done one-time after starting sampling, since this value does not change.

unsigned long ulNSamplingElements = 0;     // --> Columns

if (NMX_Sampling_GetStatus_1(pHandleNmx, NULL, &ulNSamplingElements, NULL, NULL) != NST_SUCCESS) {

 // Error reading sampling status. Do some error handling.

 return;

}

 

// ###-> Read newest data. This code could for example be done after the notification NMXNOTIFY_SAMPLING_NEW_DATA.

signed long *aslSamples = new signed long[ulNSamplingElements];

unsigned long ulSamplesCopied = 0;

unsigned long long udSampleNo = 0;

NMX_STATUS tResult = NST_SUCCESS;

 

do {

 tResult = NMX_Sampling_ReadRow32_1(pHandleNmx, aslSamples, ulNSamplingElements, &ulSamplesCopied, &udSampleNo);

 if (tResult == NST_SUCCESS) {

         // New row has been read-out. Use the data, e.g. copy it to your own array or ring-buffer.

 }

 else if (tResult == NST_SAMPLING_NO_DATA_AVAILABLE) {

         // No more data available. Wait until new data has arrived.

         break;

 }

 else {

         // An error occurred. Do some error handling.

         break;

 }

} while (1);

 

Delphi


var

  ucStatus: byte;

  udSamplesReceived: uint64;

  udSamplesMax: uint64;

  ulNElements: cardinal;

  aslSamples: packed array of integer;

  ulSamplesCopied: cardinal;

  udSampleNo: uint64;

  tResult: NMX_STATUS;

begin

  ucStatus := 0;

  udSamplesReceived := 0;

  udSamplesMax := 0;

  ulNElements := 0;

 

  // ###-> Get Number of Sampling elements. This could be done one-time after starting sampling, since this value does not change.

  if cNmx.Sampling_GetStatus_1(pHandleNmx, ucStatus, ulNElements, udSamplesReceived, udSamplesMax) <> NST_SUCCESS then begin

 // Error reading sampling number of sampling elements. Do some error handling.

 exit;

  end;

 

  // ###-> Read newest data. This code could for example be done after the notification NMXNOTIFY_SAMPLING_NEW_DATA.

  SetLength(aslSamples, ulNElements);

  while (true) do begin

    tResult := cNmx.Sampling_ReadRow32_1(pHandleNmx, aslSamples, Length(aslSamples), ulSamplesCopied, udNoFirstSample);

    if tResult = NST_SUCCESS then begin

      // New row has been read-out. Use the data, e.g. copy it to your own array or ring-buffer.

    end

    else if tResult = NST_SAMPLING_NO_DATA_AVAILABLE then begin

      // No more data available. Wait until new data has arrived.

      break;

    end

    else begin 

      // Error reading sampled data. Do some error handling.

      break;

    end;

  end;

end;

 

C# / .Net


Byte ucStatus = 0;

UInt32 ulNElements = 0;

UInt64 udSamplesReceived = 0;

UInt64 udMaxSamples = 0;

UInt32 ulSamplesCopied = 0;

 

/* Get number of samples, which are available. */

cNmx.Sampling_GetStatus_1(pDevice, ref ucStatus, ref ulNElements, ref udSamplesReceived, ref udMaxSamples);

 

/* Create arrays for sampling data and read it from DLL */

Int32[] aslValues = new Int32[ulNElements];

 

while (true)

{

   for (Int32 I = 0; I < aslValues.Length; I++) aslValues[I] = Int32.MaxValue;

 

  /* Read samples from DLL into local array */

   UInt32 ulSamplesCopied = 0;

   NMX_MSTATUS tStatus = cNmx.Sampling_ReadRow32_1(pDevice, aslValues, ref ulSamplesCopied, ref udNoFirstSample);

  if (tStatus == NMX_MSTATUS.SUCCESS)

   {

      // New row has been read-out. Use the data, e.g. copy it to your own array or ring-buffer.

   }

  else if (tStatus == NMX_MSTATUS.SAMPLING_NO_DATA_AVAILABLE)

   {

      // No more data available. Wait until new data has arrived.

      break;

   }

  else

   {

      // An error occurred. Do some error handling.

      break;

   }

}