01.txt

VB文章集（含API、窗口、数据库、多媒体、系统、文件、等等）

1、怎么用mscomm控件检测modem是否与计算机联接正确？2、如何用mscomm挂断modem与别的电话机间的连接？（已接通）
我用mscomm写了一个拨号程序，有二个问题想请教： 
1、怎么用mscomm控件检测modem是否与计算机联接正确？ 

2、如何用mscomm挂断modem与别的电话机间的连接？（已接通） 
连接 

我记得MODEN连接好了可以接受串口的信号，比如，你发送AT，应该返回OK，有的时候则返回AT，说明是连上了的 

Function ModenSeach(com As Integer, Default As String) As String 
Dim a As String 
On Error GoTo aa: 
MSComm.CommPort = com 
MSComm.InputMode = comInputModeBinary 
MSComm.Settings = "9600,n,8,1" 
If MSComm.PortOpen = True Then 
MSComm.PortOpen = False 
End If 
MSComm.DTREnable = True 
MSComm.EOFEnable = True 
MSComm.RTSEnable = True 
MSComm.PortOpen = True 
MSComm.Output = "at" 
a = EcrReadOne(2): a = LCase(a) 
If InStr(a, "at") <> 0 Or InStr(a, "ok") <> 0 Then 
ModenSeach = "Moden" 
Else 
ModenSeach = Default 
End If 
Exit Function 
aa: 
ModenSeach = Default 
'EndTransmit 
End Function 

Function EcrReadOne(number As Integer) As String 
Dim out() As Byte, i As Integer, data As String 

data = "": i = 1 
Do 
DoEvents: i = i + 1 
Debug.Print MSComm.InBufferCount 
Loop Until (MSComm.InBufferCount >= number Or i >= 800) ' one plu item read 
If i >= 800 Then 
EcrReadOne = "" 
Exit Function 
End If 
out() = MSComm.Input 
For i = 1 To number 
data = data + Chr(out(i)) 
Next 
EcrReadOne = Trim(data) 
End Function