Read com port

[favory]

I'm trying to read a data from the COM port:

include "FiveWin.ch"

function Comm()

local oDlg, nComm := InitComm()

DEFINE DIALOG oDlg TITLE "Testing Comm functions"


*** timet ***
* DEFINE TIMER oTmr INTERVAL 100 ACTION BytesAtPort( nComm, nStatus ) OF oWnd
* ACTIVATE TIMER oTmr
*************


oDlg:bCommNotify = { | nComm, nStatus | BytesAtPort( nComm, nStatus ) }

ACTIVATE DIALOG oDlg ;
ON INIT EnableCommNotification( nComm, oDlg:hWnd, 20, 20 )

CloseComm( nComm )

return nil


*********************************************

function InitCOMM()

local cDcb, nError, nBytes
local nComm := OpenComm( "COM1", 1024, 128 )
local cF := 'commTest.log'

FErase( cF )

if nComm=1
LogFile( cF, { 'Otvoren COM 1 port ' + '9600' } )
endif

if ! BuildCommDcb( "COM1:9600,n,8,1", @cDcb )
MsgStop( "Error BUILD!" )
return .f.
endif

if ! SetCommState( cDcb )
MsgStop( "Error SETCOMM!" )
return .f.
endif

return nComm


*********************************************

function BytesAtPort( nComm, nStatus )

local cBuffer := Replicate(Chr(255),1024)
local cF := 'commTest.log'


ReadComm( nComm, @cBuffer ) // <<<<---- program will lock here

cBuffer:=StrTran(cBuffer,Chr(255),'')

LogFile( cF, { cBuffer } )

return nil


everything is fine but the result is:

09.04.2011 08:01:52: Otvoren COM 1 port 9600
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the com port is currently connected mouse

I have no experience with this. I need any help!

best regards
Miloš

[Enrico Maria Giordano]

This is a sample:

Code: Select all

#include "Fivewin.ch"


FUNCTION MAIN()

    LOCAL oDlg

    LOCAL oGet, cTxt := ""

    LOCAL nCom

    DEFINE DIALOG oDlg;
           SIZE 500, 500;
           TITLE "Terminale"

    @ 0, 0 GET oGet VAR cTxt MEMO READONLY

    oGet:bKeyDown = { | nKey | Tasti( nCom, nKey ) }

    ACTIVATE DIALOG oDlg;
             ON INIT ( oGet:AdjClient(),;
                       nCom := APRICOM( oDlg, oGet ),;
                       IF( nCom < 0, oDlg:End(), ) );
             CENTER

    IF nCom >= 0; CLOSECOMM( nCom ); ENDIF

    RETURN NIL


STATIC FUNCTION TASTI( nCom, nKey )

    SENDSTR( nCom, CHR( nKey ) )

    RETURN NIL


STATIC FUNCTION APRICOM( oDlg, oGet )

    LOCAL nCom, cDcb

    BEGIN SEQUENCE
        nCom = OPENCOMM( "COM1", 16384, 16384 )

        IF nCom < 0
            ? "Errore di apertura della porta di comunicazione."
            BREAK
        ENDIF

        BUILDCOMMDCB( "COM1:115200,N,8,1", @cDcb )

        IF !SETCOMMSTATE( nCom, cDcb )
            ? "Errore di impostazione della porta di comunicazione."
            BREAK
        ENDIF

        oDlg:bCommNotify = { | nCom | Connect( nCom, oGet ),;
                                      EnableCommNotification( nCom, oDlg:hWnd, 1, -1 ) }

        IF !ENABLECOMMNOTIFICATION( nCom, oDlg:hWnd, 1, -1 )
            ? "Errore di abilitazione della notifica."
            BREAK
        ENDIF
    RECOVER
        nCom = -1
    END SEQUENCE

    RETURN nCom


STATIC FUNCTION CONNECT( nCom, oGet )

    LOCAL cStr

    ENABLECOMMNOTIFICATION( nCom, 0, 1, -1 )

    cStr = RECEIVESTR( nCom )

    cStr = STRTRAN( cStr, CHR( 13 ), "" )
    cStr = STRTRAN( cStr, CHR( 10 ), CRLF )

    oGet:Append( cStr )

    RETURN NIL


STATIC FUNCTION SENDSTR( nCom, cString )

    LOCAL nBytes := WRITECOMM( nCom, cString )

    RETURN nBytes = LEN( cString )


STATIC FUNCTION RECEIVESTR( nCom )

    LOCAL cBuf := SPACE( 1000 )

    RETURN LEFT( cBuf, READCOMM( nCom, @cBuf ) )

EMG

[favory]

I'm not sure what should be the result. How can conclude that the port is opened, read and write is OK but with no results. These are the values ​​of variables:

04/10/2011 08:46:59: NCOM = 1
04/10/2011 08:46:59: CSTR =
04/10/2011 08:46:59: Nbytes = 0
04/10/2011 08:46:59: nkey = E
04/10/2011 08:46:59: LEFT (cBuf, READCOMM (NCOM, cBuf @)) =

In what could be the problem?

best regards
Miloš

[Enrico Maria Giordano]

You can test my sample using a modem or just look at the code and follow it as a guideline.

EMG

[mtajkov]

before the start of your examples status of the com port is 1200, none, 7,1 (if in the Windows taskbar set to 9600, none, 8.1). After starting examples port status is not changed. The program does not report any error but does not even make the com port setting. Why? What could be the problem?

[Enrico Maria Giordano]

This is che function to set the com port:

Code: Select all

BUILDCOMMDCB( "COM1:115200,N,8,1", @cDcb )

Try to play with the parameters.

EMG

[mtajkov]

anything that I type does not respond to commands. If you execute the setup hyper terminal and after that run all the example of doing well?

[Enrico Maria Giordano]

Sorry, I didn't understand you question. Anyway, you can test my sample using a modem or another PC connected to the serial port.

EMG

[mtajkov]

BUILDCOMMDCB ("COM1: 115200, N, 8.1", @ cDcb) simply does not work! Com port settings are the same as before the execution of commands!

[Enrico Maria Giordano]

You can't see the port setting in the control panel. Please use a device connected to the com port (ie. a modem or another PC) to test my sample.

EMG

[favory]

I am using Datalogic barcode scanner. If the DOS prompt and typing mode COM1: 9600, n, 8.1 everything is working properly, and you and my program. But the initialization with the command BUILDCOMMDCB ("COM1: 115200, N, 8.1", @ cDcb) can not do that. In setting the com port is not changing!

Sorry for my English!

[Enrico Maria Giordano]

So, try

Code: Select all

BUILDCOMMDCB ("COM1: 9600, N, 8.1", @ cDcb)

EMG

[favory]

command

Code: Select all

BUILDCOMMDCB( "COM1:9600,N,8,1", @cDcb )

has no effect on the com port!

Code: Select all

*********************************************

function InitCOMM()

   local cDcb, nError, nBytes
   local nComm := OpenComm( "COM1", 1024 , 128)


   if ! BuildCommDcb( "COM1:9600,N,8,1", @cDcb )
      MsgStop( "Error BUILD!" )
      return .f.
   endif


   if ! SetCommState( cDcb )
      MsgStop( "Error SETCOMM!" )
      return .f.
   endif


return nComm


 

I do not see any error ..?

[Enrico Maria Giordano]

Code: Select all

if ! SetCommState( cDcb )

Code: Select all

if ! SetCommState( nComm, cDcb )

EMG

[favory]

still does not work!