Labwindows cvi2017函数信号发生器完整代码

以下是一个简单的 LabWindows/CVI 2017 函数信号发生器的完整代码示例：

#include <cvirte.h>
#include <userint.h>
#include <utility.h>
#include <ansi_c.h>
#include <analysis.h>

#define PI 3.14159265358979323846

static int panelHandle;

double sineWave(double amplitude, double frequency, double time)
{
    return amplitude * sin(2.0 * PI * frequency * time);
}

double squareWave(double amplitude, double frequency, double time)
{
    double period = 1.0 / frequency;
    double halfPeriod = period / 2.0;
    double t = fmod(time, period);

    if (t < halfPeriod)
        return amplitude;
    else
        return -amplitude;
}

double triangleWave(double amplitude, double frequency, double time)
{
    double period = 1.0 / frequency;
    double t = fmod(time, period);
    double slope = amplitude / (period / 2.0);

    if (t < period / 2.0)
        return slope * t;
    else
        return slope * (period - t) - amplitude;
}

int CVICALLBACK panelCallback(int panel, int event, void *callbackData,
        int eventData1, int eventData2)
{
    switch (event)
    {
        case EVENT_CLOSE:
            QuitUserInterface(0);
            break;
    }

    return 0;
}

int main (int argc, char *argv[])
{
    double (*waveFunc)(double, double, double) = sineWave; // 默认使用正弦波
    double amplitude = 1.0;
    double frequency = 1.0;
    double sampleRate = 1000.0;
    double duration = 1.0;
    double timeStep = 1.0 / sampleRate;
    double *data;
    int numSamples;
    int i;

    if (InitCVIRTE (0, argv, 0) == 0)
        return -1;

    panelHandle = LoadPanel (0, "panel.uir", PANEL);
    SetPanelAttribute(panelHandle, ATTR_CALLBACK_DATA, NULL);

    InstallCtrlCallback(panelHandle, PANEL_WAVE_TYPE, waveTypeCallback, &waveFunc);
    InstallCtrlCallback(panelHandle, PANEL_AMPLITUDE, amplitudeCallback, &amplitude);
    InstallCtrlCallback(panelHandle, PANEL_FREQUENCY, frequencyCallback, &frequency);
    InstallCtrlCallback(panelHandle, PANEL_SAMPLE_RATE, sampleRateCallback, &sampleRate);
    InstallCtrlCallback(panelHandle, PANEL_DURATION, durationCallback, &duration);
    InstallCtrlCallback(panelHandle, PANEL_GENERATE_BUTTON, generateButtonCallback, &data);

    SetCtrlVal(panelHandle, PANEL_WAVE_TYPE, 0);
    SetCtrlVal(panelHandle, PANEL_AMPLITUDE, amplitude);
    SetCtrlVal(panelHandle, PANEL_FREQUENCY, frequency);
    SetCtrlVal(panelHandle, PANEL_SAMPLE_RATE, sampleRate);
    SetCtrlVal(panelHandle, PANEL_DURATION, duration);

    DisplayPanel(panelHandle);
    RunUserInterface();

    FreeWaveform(data);

    DiscardPanel(panelHandle);
    CloseCVIRTE();

    return 0;
}

int CVICALLBACK waveTypeCallback(int panel, int control, int event, void *callbackData,
        int eventData1, int eventData2)
{
    double (*waveFunc)(double, double, double) = (double (*)(double, double, double))callbackData;

    switch (event)
    {
        case EVENT_COMMIT:
            switch (GetCtrlVal(panelHandle, PANEL_WAVE_TYPE))
            {
                case 0:
                    *waveFunc = sineWave;
                    break;
                case 1:
                    *waveFunc = squareWave;
                    break;
                case 2:
                    *waveFunc = triangleWave;
                    break;
            }
            break;
    }

    return 0;
}

int CVICALLBACK amplitudeCallback(int panel, int control, int event, void *callbackData,
        int eventData1, int eventData2)
{
    double *amplitude = (double *)callbackData;

    switch (event)
    {
        case EVENT_COMMIT:
            GetCtrlVal(panelHandle, PANEL_AMPLITUDE, amplitude);
            break;
    }

    return 0;
}

int CVICALLBACK frequencyCallback(int panel, int control, int event, void *callbackData,
        int eventData1, int eventData2)
{
    double *frequency = (double *)callbackData;

    switch (event)
    {
        case EVENT_COMMIT:
            GetCtrlVal(panelHandle, PANEL_FREQUENCY, frequency);
            break;
    }

    return 0;
}

int CVICALLBACK sampleRateCallback(int panel, int control, int event, void *callbackData,
        int eventData1, int eventData2)
{
    double *sampleRate = (double *)callbackData;

    switch (event)
    {
        case EVENT_COMMIT:
            GetCtrlVal(panelHandle, PANEL_SAMPLE_RATE, sampleRate);
            break;
    }

    return 0;
}

int CVICALLBACK durationCallback(int panel, int control, int event, void *callbackData,
        int eventData1, int eventData2)
{
    double *duration = (double *)callbackData;

    switch (event)
    {
        case EVENT_COMMIT:
            GetCtrlVal(panelHandle, PANEL_DURATION, duration);
            break;
    }

    return 0;
}

int CVICALLBACK generateButtonCallback(int panel, int control, int event, void *callbackData,
        int eventData1, int eventData2)
{
    double *data = (double *)callbackData;
    double amplitude;
    double frequency;
    double sampleRate;
    double duration;
    double timeStep;
    int numSamples;
    int i;

    switch (event)
    {
        case EVENT_COMMIT:
            GetCtrlVal(panelHandle, PANEL_AMPLITUDE, &amplitude);
            GetCtrlVal(panelHandle, PANEL_FREQUENCY, &frequency);
            GetCtrlVal(panelHandle, PANEL_SAMPLE_RATE, &sampleRate);
            GetCtrlVal(panelHandle, PANEL_DURATION, &duration);

            timeStep = 1.0 / sampleRate;
            numSamples = (int)(duration * sampleRate);
            *data = (double *)MallocWaveform(sizeof(double) * numSamples);

            for (i = 0; i < numSamples; i++)
            {
                (*data)[i] = (*waveFunc)(amplitude, frequency, i * timeStep);
            }

            PlotY(panelHandle, PANEL_GRAPH, *data, numSamples, VAL_DOUBLE, VAL_THIN_LINE, VAL_EMPTY_SQUARE, VAL_SOLID, 1, VAL_BLUE);
            break;
    }

    return 0;
}

这个程序使用了三个不同的波形函数：正弦波，方波和三角波。您可以使用“波形类型”下拉列表框选择要生成的波形类型，然后设置振幅，频率，采样率和持续时间。单击“生成”按钮将生成波形数据，并将其绘制在图形窗口中。