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Thread: clear hyperterminal in vb.net

  1. #1

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    Fanatic Member ksuwanto8ksd's Avatar
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    clear hyperterminal in vb.net

    please help,

    in hyper teriminal when i press "ctrl+L" is to clear terminal screen
    how to write the code in vb.net? Hyperterminal is connecting to serial comport

    when i try this it work and return line on debug
    Code:
    serialport.writeline ("at+cmgl=1")
    i try this but not work and it still show some lines on debug
    Code:
    serialport.writeline (vbcrtl +"L")
    serialport.WriteLine("vbCrLf + l")
    thanks

    best regards,

  2. #2
    Powered By Medtronic dbasnett's Avatar
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    Re: clear hyperterminal in vb.net

    It is not clear what you are trying to do. It looks like you were using HyperTerminal to talk to a device and then wanted to automate that with VisualBasic.

    In basic terminal communications, like HyperTerminal, the control sequence, CTRL-L, is a FormFeed (ControlChars.FormFeed), which clears the screen.

    SerialPort.Writexxx / .Readxxx does not have a concept of screen, only of bit streams.
    My First Computer -- Documentation Link (RT?M) -- Using the Debugger -- Prime Number Sieve
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  3. #3

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    Re: clear hyperterminal in vb.net

    thanks for your ********
    yes,it is. that is what i supposed to do to send a "ctrl + L" trying to clear hyperterminal data so that it is "empty" when i do serialport.readline command.

    If serialport still got data it will read it when I accesing command "serialport.readine"

  4. #4
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    Re: clear hyperterminal in vb.net

    Clearing Hyperteminal has no effect on reading the serial port in your program -- anthing displayed in Hyperterminal has already been read and is no longer available from the serial port. However, you cannot have both Hyperterminal and your program both executing (with the serial port open), so I suspect that something else is going on.

    Do you have terminal code in your own program that is displaying data? If so, then just clear the textbox that is displaying the data. If not, and you want to use a terminal program to display data, then add that code (I have example code on my website, www.hardandsoftware.net, in the Enhanced SerialPort download).

    If you actually have Hyperterminal running, then... what you want to do is not practical. Do it some other way.

    Dick
    Richard Grier, Consultant, Hard & Software
    Microsoft MVP (Visual Basic)

  5. #5

    Thread Starter
    Fanatic Member ksuwanto8ksd's Avatar
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    Re: clear hyperterminal in vb.net

    hi DickGrier
    thanks for your response

    i am using serialport.writeline ("at+cmgl=1") to access serialport and then using serialport.readline command to read from serialport.
    Unfortunately, serialport.readline can read only 1 line each turn, the rest have few line left, and i suppose to clear the rest of it.

    example:
    Code:
                                SMSPort.WriteLine("AT+CMGL=1" & vbCr)
                                t1 = SMSPort.ReadLine() 'THIS READ FIRST LINE
                                t2 = SMSPort.ReadLine() 'THIS READ 2ND LINE
    actually, the device have more than 2 line when i perform serialport.readline("at+cmgl=1"), this is I suposse to clear the rest (the 3rd line and more)

    Regards,

  6. #6
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    Re: clear hyperterminal in vb.net

    IMO, you should add code to the DataAvailable event to read data. Then, do not use ReadLine, but instead use ReadExisting. You can double-buffer data to a String buffer by appending new data. Then either use the Substring method or the InStr function to scan the buffer for a vbCrLf. When you find a part of the string terminated by the carriage return/linefeed character pair (vbCrLf or ControlChars.NewLine), then display that line by invoking a delegate. Don't forget to remove any data from the String buffer that you already have displayed.

    There are lots of examples of this sort of thing online.

    Dicki
    Richard Grier, Consultant, Hard & Software
    Microsoft MVP (Visual Basic)

  7. #7

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    Re: clear hyperterminal in vb.net

    [QUOT]
    you cannot have both Hyperterminal and your program both executing (with the serial port open), so I suspect that something else is going on
    [/QUOT]
    yes, i am not open hyperterminal when my program accessing it, i am sorry for the title include hyperterminal, that must be reagarding serialport or whatever, idk

    Regards,

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