How to find out if modem is active?

How to find out if modem is active?
(in code, of course:).

Thanks.
neoxAsked:
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intheCommented:
you can try and open the comm port like so.. the following is for initializiting a modem so you can use it and if it returns the message 'unable to open..' then the modem is in use.
 
procedure InitModem;
Var CommPortTimeOuts: TCommTimeouts;
    DCB: TDCB;
    hCommFile : THandle;
  ReadBuffer: array[0..100] of char;
  NumberRead: DWord;
begin
 
    { Open the comm port. }
    hCommFile := CreateFile(PChar('COM1'),GENERIC_READ +
GENERIC_WRITE,0,nil,OPEN_EXISTING,FILE_FLAG_WRITE_THROUGH,0);
    if hCommFile = INVALID_HANDLE_VALUE then
    begin
          ShowMessage('Unable to open COM1!');
          exit;
    end;
 
    { Set Timeout values for the comm port. }
    CommPortTimeOuts.ReadIntervalTimeout        := 100;
    CommPortTimeOuts.ReadTotalTimeoutMultiplier  := 100;
    CommPortTimeOuts.ReadTotalTimeoutConstant    := 0;
    CommPortTimeOuts.WriteTotalTimeoutMultiplier := 0;
    CommPortTimeOuts.WriteTotalTimeoutConstant  := 0;
    SetCommTimeOuts(hCommFile,CommPortTimeOuts);
 
    { Set the comm port parameters. }
    GetCommState(hCommFile,DCB);
    DCB.BaudRate := 1200;
    DCB.ByteSize := 7;
    DCB.StopBits := ONESTOPBIT;
    DCB.Parity  := EVENPARITY;
    SetCommState(hCommFile,DCB);
 
    { Send initialization string to the port. }
    ReadBuffer := '';
    StrPCopy(ReadBuffer,'ATZ' + #13 + #10);
 
WriteFile(hCommFile,ReadBuffer,Length(ReadBuffer),NumberRead,NIL);
 
    { Get a response from the port. }
    ReadBuffer := '';
    ReadFile(hCommFile,ReadBuffer,100,NumberRead,NIL);
 
    { Close the port. }
    CloseHandle(hCommFile);
end;


Regards Barry
0

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