Serial Communication

DELPHI 2/3

//{$DEFINE COMM_UNIT}

//Simple_comm door E.L. Lagerburg voor Delphi 2.01 Maart 1997
//Nog niet getest
//Compiler maakt Simple_Comm.Dll of Simple_Com.Dcu afhankelijk van 1e Regel
(COMM_UNIT)

{$IFNDEF COMM_UNIT}
library Simple_Comm;
{$ELSE}
Unit Simple_Comm;
Interface
{$ENDIF}

  Uses Windows,Messages;


Const M_BaudRate =1;
Const M_ByteSize =2;
Const M_Parity   =4;
Const M_Stopbits =8;

{$IFNDEF COMM_UNIT}
{$R Script2.Res}     //versie informatie 
{$ENDIF}



{$IFDEF COMM_UNIT}
Function Simple_Comm_Info:PChar;StdCall;
Function
Simple_Comm_Open(Port:PChar;BaudRate:DWORD;ByteSize,Parity,StopBits:Byte;Mas
k:Integer;WndHandle:HWND;WndCommand:UINT;Var Id:Integer):Integer;StdCall;
Function Simple_Comm_Close(Id:Integer):Integer;StdCall;
Function
Simple_Comm_Write(Id:Integer;Buffer:PChar;Count:DWORD):Integer;StdCall;
Function Simple_Comm_PortCount:DWORD;StdCall;

Const M_None     =  0;
Const M_All      = 15;


Implementation
{$ENDIF}

Const InfoString = 'Simple_Comm.Dll (c)  by E.L. Lagerburg 1997';
const MaxPorts = 5;

Const bDoRun :    Array[0..MaxPorts-1] of boolean
=(False,False,False,False,False);
Const hCommPort:  Array[0..MaxPorts-1] of Integer =(0,0,0,0,0);
Const hThread:    Array[0..MaxPorts-1] of Integer =(0,0,0,0,0);
Const dwThread:   Array[0..MaxPorts-1] of Integer =(0,0,0,0,0);
Const hWndHandle: Array[0..MaxPorts-1] of Hwnd    =(0,0,0,0,0);
Const hWndCommand:Array[0..MaxPorts-1] of UINT    =(0,0,0,0,0);
Const PortCount:Integer                           = 0;


Function Simple_Comm_Info:PChar;StdCall;
Begin
  Result:=InfoString;
End;

//Thread functie voor lezen compoort
Function Simple_Comm_Read(Param:Pointer):Longint;StdCall;
Var Count:Integer;
    id:Integer;
    ReadBuffer:Array[0..127] of byte;
Begin
  Id:=Integer(Param);
  While bDoRun[id] do
  Begin
    ReadFile(hCommPort[id],ReadBuffer,1,Count,nil);
    if (Count > 0) then
    Begin
      if ((hWndHandle[id]<> 0) and
         (hWndCommand[id] >> WM_USER)) then
                
SendMessage(hWndHandle[id],hWndCommand[id],Count,LPARAM(@ReadBuffer));
    End;
  End;
  Result:=0;
End;


//Export functie voor sluiten compoort
Function Simple_Comm_Close(Id:Integer):Integer;StdCall;
Begin
  if (ID < 0) or (id > MaxPorts-1) or (not bDoRun[Id]) then
  Begin
    Result:=ERROR_INVALID_FUNCTION;
    Exit;
  End;
  bDoRun[Id]:=False;
  Dec(PortCount);
  FlushFileBuffers(hCommPort[Id]);
  if not
PurgeComm(hCommPort[Id],PURGE_TXABORT+PURGE_RXABORT+PURGE_TXCLEAR+PURGE_RXCL
EAR) then
  Begin
    Result:=GetLastError;
    Exit;
  End;
  if WaitForSingleObject(hThread[Id],10000) = WAIT_TIMEOUT then
           if not TerminateThread(hThread[Id],1) then
           Begin
             Result:=GetLastError;
             Exit;
           End;

  CloseHandle(hThread[Id]);
  hWndHandle[Id]:=0;
  hWndCommand[Id]:=0;
  if not CloseHandle(hCommPort[Id]) then
  Begin
    Result:=GetLastError;
    Exit;
  End;
  hCommPort[Id]:=0;
  Result:=NO_ERROR;
End;


Procedure Simple_Comm_CloseAll;StdCall;
Var Teller:Integer;
Begin
  For Teller:=0 to MaxPorts-1 do
  Begin
    if bDoRun[Teller] then Simple_Comm_Close(Teller);
  End;
End;

Function GetFirstFreeId:Integer;StdCall;
Var Teller:Integer;
Begin
  For Teller:=0 to MaxPorts-1 do
  Begin
    If not bDoRun[Teller] then
    Begin
      Result:=Teller;
      Exit;
    End;
  End;
  Result:=-1;
End;

//Export functie voor openen compoort
Function
Simple_Comm_Open(Port:PChar;BaudRate:DWORD;ByteSize,Parity,StopBits:Byte;Mas
k:Integer;WndHandle:HWND;WndCommand:UINT;Var Id:Integer):Integer;StdCall;
 Var PrevId:Integer;
     ctmoCommPort:TCOMMTIMEOUTS; //Lees specificaties voor de compoort
     dcbCommPort:TDCB;
Begin
  if (PortCount >= MaxPorts) or (PortCount < 0) then
  begin
    result:=error_invalid_function;
    exit;
  end;
  result:=0;
  previd:=id;
  id:=getfirstfreeid;
  if id = -1 then
  begin
    id:=previd;
    result:=error_invalid_function;
    exit;
  end;
  hcommport[id]:=createfile(port,generic_read or
generic_write,0,nil,open_existing,file_attribute_normal,0);
  if hcommport[id]= invalid_handle_value then
  begin
    bdorun[id]:=false;
    id:=previd;
    result:=getlasterror;
    exit;
  end;
  //lees specificaties voor het comm bestand
  ctmocommport.readintervaltimeout:=maxdword;
  ctmocommport.readtotaltimeoutmultiplier:=maxdword;
  ctmocommport.readtotaltimeoutconstant:=maxdword;
  ctmocommport.writetotaltimeoutmultiplier:=0;
  ctmocommport.writetotaltimeoutconstant:=0;
  //instellen specificaties voor het comm bestand
  if not setcommtimeouts(hcommport[id],ctmocommport) then
  begin
    bdorun[id]:=false;
    closehandle(hcommport[id]);
    id:=previd;
    result:=getlasterror;
    exit;
  end;
  //instellen communicatie
  dcbcommport.dcblength:=sizeof(tdcb);
  if not getcommstate(hcommport[id],dcbcommport) then
  begin
    bdorun[id]:=false;
    closehandle(hcommport[id]);
    id:=previd;
    result:=getlasterror;
    exit;
  end;
  if (mask and m_baudrate <> 0) then dcbCommPort.BaudRate:=BaudRate;
  if (Mask and M_ByteSize <> 0) then dcbCommPort.ByteSize:=ByteSize;
  if (Mask and M_Parity   <> 0) then dcbCommPort.Parity:=Parity;
  if (Mask and M_Stopbits <> 0) then dcbCommPort.StopBits:=StopBits;
  if not SetCommState(hCommPort[Id],dcbCommPort) then
  Begin
    bDoRun[Id]:=FALSE;
    CloseHandle(hCommPort[Id]);
    Id:=PrevId;
    Result:=GetLastError;
    Exit;
  End;
  //Thread voor lezen compoort
  bDoRun[Id]:=TRUE;
 
hThread[Id]:=CreateThread(nil,0,@Simple_Comm_Read,Pointer(Id),0,dwThread[Id]
);
  if hThread[Id] = 0 then
  Begin
    bDoRun[Id]:=FALSE;
    CloseHandle(hCommPort[Id]);
    Id:=PrevId;
    Result:=GetLastError;
    Exit;
  End else
  Begin
    SetThreadPriority(hThread[Id],THREAD_PRIORITY_HIGHEST);
    hWndHandle[Id]:=WndHandle;
    hWndCommand[Id]:=WndCommand;
    Inc(PortCount);
    Result:=NO_ERROR;
  End;
End;

//Export functie voor schrijven naar compoort;
Function
Simple_Comm_Write(Id:Integer;Buffer:PChar;Count:DWORD):Integer;StdCall;
Var Written:DWORD;
Begin
  if (Id < 0) or (id > Maxports-1) or (not bDoRun[Id]) then
  Begin
    Result:=ERROR_INVALID_FUNCTION;
    Exit;
  End;
  if not WriteFile(hCommPort[Id],Buffer,Count,Written,nil) then
  Begin
    Result:=GetLastError();
    Exit;
  End;
  if (Count <> Written) Then Result:=ERROR_WRITE_FAULT Else
Result:=NO_ERROR;
End;

//Aantal geopende poorten voor aanroepende applicatie
Function Simple_Comm_PortCount:DWORD;StdCall;
Begin
  Result:=PortCount;
End;

{$IFNDEF COMM_UNIT}
Exports
  Simple_Comm_Info      Index 1,
  Simple_Comm_Open      Index 2,
  Simple_Comm_Close     Index 3,
  Simple_Comm_Write     Index 4,
  Simple_Comm_PortCount index 5;

Procedure DLLMain(dwReason:DWORD);
Begin
  If dwReason = DLL_PROCESS_DETACH then Simple_Comm_CloseAll;
End;

Begin
  DLLProc:=@DLLMain;
  DLLMain(DLL_PROCESS_ATTACH);//geen nut in dit geval
End.

{$ELSE}
Initialization
Finalization
  Simple_Comm_CloseAll;
end.
{$ENDIF}

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