Советы по Delphi. Версия 1.4.3 от 1.1.2001

 if tceCts in FEvents then inc(EventMask,EV_CTS);
 if tceCtss in FEvents then inc(EventMask,EV_CTSS);
 if tceDsr in FEvents then inc(EventMask,EV_DSR);
 if tceErr in FEvents then inc(EventMask,EV_ERR);
 if tcePErr in FEvents then inc(EventMask,EV_PERR);
 if tceRing in FEvents then inc(EventMask,EV_RING);
 if tceRlsd in FEvents then inc(EventMask,EV_RLSD);
 if tceRlsds in FEvents then inc(EventMask,EV_RLSDS);
 if tceRxChar in FEvents then inc(EventMask,EV_RXCHAR);
 if tceRxFlag in FEvents then inc(EventMask,EV_RXFLAG);
 if tceTxEmpty in FEvents then inc(EventMask,EV_TXEMPTY);
 SetCommEventMask(hComm,EventMask);
end;

procedure TComm.WndProc(var Msg:TMessage);
begin
 with Msg do begin
 if Msg=WM_COMMNOTIFY then begin
 case lParamLo of
 CN_EVENT:
 DoEvent;
 CN_RECEIVE:
 DoReceive;
 CN_TRANSMIT:
 DoTransmit;
 end;
 end else Result:=DefWindowProc(FWindowHandle, Msg, wParam, lParam);
 end;
end;

procedure TComm.DoEvent;
var
 CommEvent:TCommEvents;
 EventMask:Word;
begin
 if (hComm<0) or not Assigned(FOnEvent) then exit;
 EventMask:=GetCommEventMask(hComm,Integer($FFFF));
 CommEvent:=[];
 if (tceBreak in Events) and (EventMask and EV_BREAK<>0) then CommEvent:=CommEvent+[tceBreak];
 if (tceCts in Events) and (EventMask and EV_CTS<>0) then CommEvent:=CommEvent+[tceCts];
 if (tceCtss in Events) and (EventMask and EV_CTSS<>0) then CommEvent:=CommEvent+[tceCtss];
 if (tceDsr in Events) and (EventMask and EV_DSR<>0) then CommEvent:=CommEvent+[tceDsr];
 if (tceErr in Events) and (EventMask and EV_ERR<>0) then CommEvent:=CommEvent+[tceErr];
 if (tcePErr in Events) and (EventMask and EV_PERR<>0) then CommEvent:=CommEvent+[tcePErr];
 if (tceRing in Events) and (EventMask and EV_RING<>0) then CommEvent:=CommEvent+[tceRing];
 if (tceRlsd in Events) and (EventMask and EV_RLSD<>0) then CommEvent:=CommEvent+[tceRlsd];
 if (tceRlsds in Events) and (EventMask and EV_Rlsds<>0) then CommEvent:=CommEvent+[tceRlsds];
 if (tceRxChar in Events) and (EventMask and EV_RXCHAR<>0) then CommEvent:=CommEvent+[tceRxChar];
 if (tceRxFlag in Events) and (EventMask and EV_RXFLAG<>0) then CommEvent:=CommEvent+[tceRxFlag];
 if (tceTxEmpty in Events) and (EventMask and EV_TXEMPTY<>0) then CommEvent:= CommEvent+[tceTxEmpty];
 FOnEvent(Self,CommEvent);
end;

procedure TComm.DoReceive;
var Stat:TComStat;
begin
 if (hComm<0) or not Assigned(FOnReceive) then exit;
 GetCommError(hComm,Stat);
 FOnReceive(Self,Stat.cbInQue);
 GetCommError(hComm,Stat);
end;

procedure TComm.DoTransmit;
var Stat:TComStat;
begin
 if (hComm<0) or not Assigned(FOnTransmit) then exit;
 GetCommError(hComm,Stat);
 FOnTransmit(Self,Stat.cbOutQue);
end;

procedure TComm.Loaded;
begin
 inherited Loaded;