Mega Code Archive
How can I read from a modem
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Title: How can I read from a modem ?
Question: How can I read from a modem ?
Answer:
You can open comm port like:
Var
PortSpec : array[0..255] of char;
PortNo : Word;
success : Boolean;
error:integer;
begin
FillChar(PortSpec,Sizeof(PortSpec),#0);
StrPCopy(PortSpec,'Com1:19200,n,8,1');
PortSpec[3]:=Char(Ord(PortSpec[3])+Ord(PortNo));
if not BuildCommDCB(PortSpec,Mode) Then
Begin
//something wrong...
Exit;
End;
PortSpec[5]:=#0; { 'Com1:' }
Mode.Flags:=EV_RXCHAR + EV_EVENT2; { $1001 }
Com := CreateFile(PortSpec,GENERIC_READ or GENERIC_WRITE,
0, //* comm devices must be opened w/exclusive-access*/
Nil, //* no security attrs */
OPEN_EXISTING, //* comm devices must use OPEN_EXISTING*/
0, //* not overlapped I/O */
0 //* hTemplate must be NULL for comm devices */
);
if Com = INVALID_HANDLE_VALUE then Error := GetLastError;
Success := GetCommState(Com,Mode);
if not Success then // Handle the error.
begin
end;
Mode.BaudRate := 19200;
Mode.ByteSize := 8;
Mode.Parity := NOPARITY;
Mode.StopBits := ONESTOPBIT;//needed to rewrite on NT
Success := SetCommState(Com, Mode);
if not Success then // Handle the error.
begin
end;
end;
it opens the port. the "com" variable is dword.
You can clear comm buffer with
PurgeComm(Com,PURGE_RXCLEAR or PURGE_TXCLEAR);
and read with
Function ReadCh(Var Ch:Byte):dword;
var
n : dword;
Begin
Readfile(Com,ch,1,result,nil);
End;
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