How to continuous data acquisition and save to an excel file using vc++

Question

Hi,
I’m trying to build an MFC application with MSVC++6, where I would continuously acquire
samples from 2 channels of a USB-6289. I’m using the DAQmx C functions.  I use the following codes to continuously get data:
DAQmxErrChk(DAQmxCreateAIVoltageChan(taskHandle,"Dev1/ai0,Dev1/ai1","",DAQmx_Val_Cfg_Default,-10.0,10.0,DAQmx_Val_Volts,NULL));
DAQmxErrChk(DAQmxReadAnalogF64(taskHandle,1000,-1,DAQmx_Val_GroupByChannel,data,2000,&read,NULL));
        DAQmxErrChk
(DAQmxRegisterEveryNSamplesEvent(taskHandle,DAQmx_Val_Acquired_Into_Buffer,1000,0,EveryNCallback,NULL));
        DAQmxErrChk (DAQmxRegisterDoneEvent(taskHandle,0,DoneCallback,NULL));
 static int32 EveryNCallback(TaskHandle taskHandle, int32 everyNsamplesEventType, uInt32 nSamples, void *callbackData)
    int32       error=0;
    char    errBuff[2048]={'\0'};
    static int  totalRead=0;
    int32       read=0;
    float64     data[1000];
    // DAQmx Read Code
    DAQmxErrChk(DAQmxReadAnalogF64(taskHandle,1000,-1,DAQmx_Val_GroupByChannel,data,2000,&read,NULL));
   if( read>0 ) {
    fflush(stdout);
        Error:
    if( DAQmxFailed(error) ) {
        DAQmxGetExtendedErrorInfo(errBuff,2048);
        DAQmxStopTask(taskHandle);
        DAQmxClearTask(taskHandle);
            return 0;
static int32 CVICALLBACK DoneCallback(TaskHandle taskHandle, int32 status, void *callbackData)
    int32   error=0;
    char    errBuff[2048]={'\0'};
    // Check to see if an error stopped the task.
    DAQmxErrChk (status);
Error:
    if( DAQmxFailed(error) ) {
        DAQmxGetExtendedErrorInfo(errBuff,2048);
            //MessageBox("errors in DoneCallBack");
        DAQmxClearTask(taskHandle);
        //MessageBox(errBuff);
    return 0;
I have two questions:
1. how to save the data into an excel file? Can anyone show me some sample codes please?
2.Are
the data acquired from the two channels simultaneously? If I set the
starting time at 0, sample frequency 1khz, can I directly multiply the
sample number by 0.001 to calculate time (as shown below)?
Time    channel1  channel2
0.001    d11           d21
0.002    d12           d22
Thank you! 

Answer 1

You aren't going to get much help with Visual C++ programing when asking questions in the LabVIEW forum. 
Try the Measurement Studio for Visual C++ forum.
Message Edited by Ravens Fan on 12-05-2008 04:24 PM