目前使用 100Hz, -5V~5V, Sine波,  作為我的訊號源

使用DAQ卡取樣, sample rate 200Hz, 取樣數10筆, one channel

現在我用FastLine要將取樣的點畫在Chart上, 程式碼如下:


[code cpp]

//針對Chart屬性先定義, 並動態新增一個series
void __fastcall TForm1::DataOutPrepare()
{
VolChart->BottomAxis->Automatic = false;
VolChart->BottomAxis->Minimum = 0;
VolChart->BottomAxis->Maximum = 9;

VolChart->LeftAxis->Automatic = true;

TFastLineSeries *series = new TFastLineSeries(this);
VolChart->AddSeries(series);
}

//DAQ提供的Callback function, 每取樣10筆當作一次事件進來
int32 CVICALLBACK EveryNCallback(...)
{
Form1->VolChart->Series[1]->Clear();

DAQmxReadAnalogF64(....);

for(int i=0; i<10; i )
Form1->VolChart->Series[1]->Add(data[i*10 1],"",clRed); //取樣的資料都 儲存在data[ ]裡

}
[/code]



但是偶而會產生以下錯誤訊息:
List index out of bounds
如果不管他, FastLine還是會繼續動作, 但最後就會產生 EAccess Violation, 然後程式整個當掉

不知道各位前輩是否有遇過相似的問題?

編輯記錄

花了一個晚上, 自己試出來了


[code cpp]
void __fastcall TForm1::DataOutPrepare()
{
VolChart->BottomAxis->Automatic = false;
VolChart->BottomAxis->Minimum = 0;
VolChart->BottomAxis->Maximum = 9;

VolChart->LeftAxis->Automatic = true;
VolChart->LeftAxis->Increment = 0.01;
//VolChart->LeftAxis->Maximum = 5;
//VolChart->LeftAxis->Minimum = -5;

for(int i=0; i<80; i ){
TFastLineSeries *series = new TFastLineSeries(this);
VolChart->AddSeries(series);
VolChart->Series[i]->FillSampleValues(10); //先把10各點準備好
}

}

int32 CVICALLBACK EveryNCallback(...)
{

for(int i=0; i<80; i ){ //80 channel
for(int j=0; j<10; j ){ //10 samples per channel
Form1->VolChart->Series[i]->YValue[j] = data[j*80 i]; //直接修改10各點即可, 不要用Add, AddY, AddXY...
}
}

}

[/code]

這樣即使有80各Channel同時取樣也不會有問題, 結案!!!