返回实际采样频率ChannelFrq

VC/C++Builder下定义原型：
float __stdcall ChannelFrq(int NumChn,long FrqSamp);

VC/C++Builder下使用示例：
Frq = ChannelFrq(NumChn, FrqSamp);

VB下定义方式：
Declare Function DllChannelFrq Lib "ADCard.Dll" Alias "_ChannelFrq@8" (ByVal NumChn As Long, ByVal FrqSamp As Long) As Single

VB下使用示例：
Frq = DllChannelFrq(NumChn, FrqSamp)

Delphi下定义方式
function ChannelFrq(NumChn:longint; FrqSamp: longint):single;stdcall; external 'adcard.dll' name '_ChannelFrq@8';

Delphi下使用示例
Frq := ChannelFrq(NumChn, FrqSamp);

功能及参数说明：

函数ChannelFrq()返回值实际每通道的准确采样频率，单位Hz。NumChn和FrqSamp为StartIntr()或StartSnapshot()中使用的值。