Hi,
I want to construct a program for my NI USB 6009 (using Visual Studios C++, 6.0) for programming a program which:
1. Receive a trigger signal, a TTL-signal. This on one digital channel, is "Dev1/ctr0" ok?
2. When received one trigger signal starts to write a number of digital signals on another digital output for example "Dev1/port0/line7".
3. After writting the signals receive an analog value on for example "Dev1/ai0".
The problem is that I cannot control the number of "peaks" or "1" that I write with my write function (DAQmxWriteDigitalU8).
I want to be able to write for example 80 "peaks" or "1". I have given "samples to be written"=aver_num=80, but I do not see 80 "peaks" or "1" on my oscillioscope. I have tried with different digital chars to write= with the dig_char_writ ={1},with the dig_char_writ ={0,1,0,1,0,1,0,1} but this do not seem to effect the number of "peaks" or "1" that I see on my oscilloscope?
Instead of 100, I see 11 and so on, always much less. It seems random for me how many I see..
I am new in the area and excuse if I have done some fatal errors. I would be glad for some tips help!
This is my program:
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//ADC-program
// Defenitions
#include "stdafx.h"
#include "NIDAQmx.h"
#include <stdio.h>
#include <cstdio>
#include <iostream>
#define DAQmxErrChk(functionCall) if( DAQmxFailed(error=(functionCall)) ) goto Error; else
using namespace std;
int main(void)
{
int32 error=0;
char errBuff[2048]={'\0'};
TaskHandle taskHandle_1=0;
TaskHandle taskHandle_2=0;
TaskHandle taskHandle_3=0;
uInt32 data=0;
int32 aver_num=80;
const uInt8 dig_char_writ ={1};
int32 skrivna=0;
DAQmxErrChk (DAQmxCreateTask("DICount",&taskHandle_1));
DAQmxErrChk (DAQmxCreateTask("DOWrite",&taskHandle_2));
DAQmxErrChk (DAQmxCreateTask("AIRead",&taskHandle_3));
DAQmxErrChk (DAQmxCreateCICountEdgesChan(taskHandle_1,"Dev1/ctr0","",DAQmx_Val_Falling,0,DAQmx_Val_CountUp));
DAQmxErrChk (DAQmxCreateDOChan(taskHandle_2,"Dev1/port0/line7","",DAQmx_Val_ChanPerLine));
DAQmxErrChk (DAQmxCreateAIVoltageChan(taskHandle_3,"Dev1/ai0","",DAQmx_Val_Cfg_Default,-10.0,10.0,DAQmx_Val_Volts,NULL));
DAQmxErrChk (DAQmxStartTask(taskHandle_1));
for( data; data<1; data++ )
{
DAQmxErrChk (DAQmxReadCounterScalarU32(taskHandle_1,0,&data,NULL));
}
DAQmxStopTask(taskHandle_1); //Then stop this task
DAQmxClearTask(taskHandle_1);
cout << "Trigger signals from laser received: " << data << endl;
DAQmxErrChk (DAQmxStartTask(taskHandle_2));
DAQmxErrChk (DAQmxWriteDigitalU8(taskHandle_2,aver_num, 1, 10.0, DAQmx_Val_GroupByChannel,&dig_char_writ,&skrivna,NULL));
DAQmxStopTask(taskHandle_2); //Then stop this task
DAQmxClearTask(taskHandle_2);
cout << "Number of digital samples written: " << skrivna << endl;
Error:
puts("");
if( DAQmxFailed(error) )
DAQmxGetExtendedErrorInfo(errBuff,2048);
//if( taskHandle_1!=0 )
//{
//DAQmxStopTask(taskHandle_1);
//DAQmxClearTask(taskHandle_1);
//}
//if( taskHandle_2!=0 )
//{
//DAQmxStopTask(taskHandle_2);
//DAQmxClearTask(taskHandle_2);
//}
if( taskHandle_3!=0 )
{
DAQmxStopTask(taskHandle_3);
DAQmxClearTask(taskHandle_3);
}
if( DAQmxFailed(error) )
printf("DAQmx Error: %s\n",errBuff);
printf("End of program, press Enter key to quit\n");
getchar();
return 0;
}
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I would like to know why I do not see 80 "peaks" or "1"on my oscilloscope and how I can solve this? I know that there can be other ways to write this program, which I may not have realized, if there is any one who see/know an obviouse much better way I am glad for tips and help!
Kind Regards, Hanna
