Mscomm1 Event "Case comEvCTS"

Question: how could i know the receiveing is ended.
        Case comEvReceive                                   '2 Receive event.
            Buf = Buf & MSComm1.Input                  'store all
        Case comEvCTS    
                    why this part is not working ???????
please help urgent
With MSComm1
       .CommPort = 1                       'Port
         .Handshaking = comRTSXOnXOff
           .RThreshold = 1                     'Fire OnComm event with
                                                    'a single character in input buffer
           .RTSEnable = True
         .Settings = "9600,N,8,1"  'Baud
        .SThreshold = 1
      .PortOpen = True                    'Open now
End With

Private Sub MSComm1_OnComm()
    Select Case MSComm1.CommEvent
        Case comEvSend                                      '1 Send event.
        Case comEvReceive                                   '2 Receive event.
            Buf = Buf & MSComm1.Input
        Case comEvCTS                                       '3 Change in clear-to-send line.
            t_RCV.Text = t_RCV.Text & Buf & vbCrLf & "="
            v_Buf = ""
            t_RCV.SelStart = Len(t_RCV.Text)
        Case comEvDSR                                       '4 Change in data-set ready line.
        Case comEvCD                                        '5 Change in carrier detect line.
        Case comEvRing                                      '6 Ring detect.
        Case comEvEOF                                       '7 End of file.
        Case comEventBreak                                  '1001 A Break signal was received.
        Case comEventFrame                                  '1004 Framing Error. The hardware detected a framing error.
        Case comEventOverrun                                '1006 Port Overrun. A character was not read from the hardware before the next character arrived and was lost.
        Case comEventRxOver                                 '1008 Receive Buffer Overflow. There is no room in the receive buffer.
        Case comEventRxParity                               '1009 Parity Error. The hardware detected a parity error.
        Case comEventTxFull                                 '1010 Transmit Buffer Full. The transmit buffer was full while trying to queue a character.
        Case comEventDCB                                    '1011 Unexpected error retrieving Device Control Block (DCB) for the port.
    End Select

End Sub
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TimCotteeHead of Software ServicesCommented:
Hi mohittipu,

comEvCTS is used to detect a change in the "Clear-To-Send" control line. This may not work because the cable is not wired with this line in place or because you have not enabled cts or because it is not implemented in the device you are connnecting to. It is not simply a property of every configuration and something that tells you that you have finished receiving, it is up to you to know what information you are expecting back from the device and from that know it has finished or you have to simply accept every bit of data and handle in your program as appropriate.

Tim Cottee

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I would implement some sort of timeout in the program (i.e. if data is received, then when data stops being received for 30 seconds, then data transmission is complete), or if you are designing both ends of the program then sending a message to indicate end of transmission would be the best way.
Shiju SasidharanSenior IT DeveloperCommented:
>>how could i know the receiveing is ended.

it depends on the data sent by the device u connected to ur port.

if u have set
 .RThreshold = 1  
then for each character received  u will get a trigger in OnComm event
and once u make
then the reading is finished

Maybe it would be better to use a 3rd-party and forget about such problems?

Here is some very good stuff:



Serial Port ActiveX Control

to choose from
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