Salve. Stò usando la scheda di acquisizione NI PCI6229 e mentre compilo il codice fornito da voi negli esempi ho un problema:
/*********************************************************************
*
* ANSI C Example program:
* acquire1Scan.c
*
* Example Category:
* AI
*
* Description:
* This example demonstrates how to take a single Measurement
* (Sample) from an Analog Input Channel.
*
* Instructions for Running:
* 1. Select the Physical Channel to correspond to where your
* signal is input on the DAQ device.
* 2. Enter the Minimum and Maximum Voltage Ranges.
* Note: For better accuracy try to match the Input Ranges to the
* expected voltage level of the measured signal.
* Note: Use the voltUpdate example to provide a signal on
* your DAQ device to measure.
*
* Steps:
* 1. Create a task.
* 2. Create an Analog Input Voltage Channel.
* 3. Use the Read function to Measure 1 Sample from 1 Channel on
* the Data Acquistion Card. Set a timeout so an error is
* returned if the sample is not returned in the specified time
* limit.
* 4. Display an error if any.
*
* I/O Connections Overview:
* Make sure your signal input terminal matches the Physical
* Channel I/O Control.
*
* Recommended Use:
* Call the Read function.
*
*********************************************************************/
#include "NIDAQmxBase.h"
#include <stdio.h>
#define DAQmxErrChk(functionCall) { if( DAQmxFailed(error=(functionCall)) ) { goto Error; } }
int main(int argc, char *argv[])
{
// Task parameters
int32 error = 0;
TaskHandle taskHandle = 0;
char errBuff[2048]={'\0'};
// Channel parameters
char chan[] = "dev1/ai0";
float64 min = -10.0;
float64 max = 10.0;
// Timing parameters
uInt64 samplesPerChan = 1;
// Data read parameters
float64 data;
int32 pointsToRead = 1;
int32 pointsRead;
float64 timeout = 10.0;
DAQmxErrChk (DAQmxResetDevice("dev1")); DAQmxErrChk (DAQmxBaseCreateTask("",&taskHandle));
DAQmxErrChk (DAQmxBaseCreateAIVoltageChan(taskHandle,chan,"",DAQmx_Val_Cfg_Default,min,max,DAQmx_Val_Volts,NULL));
DAQmxErrChk (DAQmxBaseStartTask(taskHandle));
DAQmxErrChk (DAQmxBaseReadAnalogF64(taskHandle,pointsToRead,timeout,DAQmx_Val_GroupByChannel,&data,samplesPerChan,&pointsRead,NULL));
printf ("Acquired reading: %f\n", data);
Error:
if( DAQmxFailed(error) )
DAQmxBaseGetExtendedErrorInfo(errBuff,2048);
if( taskHandle!=0 ) {
DAQmxBaseStopTask(taskHandle);
DAQmxBaseClearTask(taskHandle);
}
if( DAQmxFailed(error) )
printf("DAQmxBase Error: %s\n",errBuff);
return 0;
}
Rispetto all'originale ho aggiunto solo la riga:
DAQmxErrChk (DAQmxResetDevice("dev1")); . La cosa strana è che senza compila, mentre con tale riga c'è l'errore:
root@nanny:/usr/local/natinst/nidaqmxbase/examples/ai# make
gcc -I../../include -O2 acquire1Scan.c -lnidaqmxbase -llvrtdark -o acquire1Scan
/tmp/ccK0zNNV.o(.text+0x57): In function `main':
: undefined reference to `DAQmxResetDevice'
collect2: ld returned 1 exit status
make: *** [acquire1Scan] Error 1Cosa può essere?
Grazie,
Massimo
)
