Shop Learn
Parallax RFID Reader USB 28340 — Parallax Forums

Parallax RFID Reader USB 28340


I have a Parallax RFID reader USB (ref 28340). After having install softwares (on the parallax website) and connect my RFID Reader USB I can read the ID of my RFID Tag (LOGI TAG 120 Unique) but only on the software RFID READER (available on the website (28340 product page -> additionnal ressources). My problem is that I can't read the ID with Excel. I tried with the PLX-DAQ worksheet but it does not work. The connection is done and the reader read the tag (also the excel document because the light of "R" turn red") but the ID it is not written in any cell.
What can I do to correct it?

Thank you for your help.


  • PLX-DAQ requires that the data string is formatted in a certain way, in particular the first word in the string is a keyword that instructs PLX-DAQ what should be done with the received data, the RFID tag does not contain a PLX-DAQ keyword.

    To display RFID numbers in Excel ROWs and COLUMNs you need a Stamp , Prop or PC app as an interface for the RFID reader. PLX-DAQ is packaged with examples for the Parallax controllers.

    It is possible to modify the PLX-DAQ VBA code so that it will read the RFID , this has limited use but I suppose it would be possible to time stamp and track tags
  • Thank you for your answer.

    Can you show me exactly what I have to do please?
  • I can't answer that question until you describe which method you would prefer to use.
  • The method doesn't matter for me, I just want to have the ID of my tags directly on excel. I can use a PC app for example
  • Modifying the Visual Basic code requires you have access to the VB editor. If the editor is not visible to you then you will need to enable it. Goto Excel Options --> Customize locate the Developer tab and add Visual Basic to the menu ribbon. If that is not clear there are many references online that will give step by step instruction, just Google "add Visual Basic to Excel".

    Once you have access to he VBA editor you should see a folder named "Forms" and inside that folder is a form named "frmStampDAQ", when you right click on that form you will have the option to "View Code", select that option. When you are comfortable that you have reached this point then post back and let me know.

    My advice would be to make a copy of the original PLX-DAQ while you make these modifications.
  • Hello, I have no problem to see the VB code I already tried to modify it.

    After making a copy, what I have to do?

    Thank you! :)
  • The Visual Basic code in frmStampDaq has two sub routines that need modification, they are stamp_DataReady and clearsheet.

    I will post the code below, it is up to you if you want to type it out yourself or copy this code and paste over your existing sub routines.

    Don't mess with any other routine, just modify the ones I mentioned.

    Private Sub stamp_DataReady()
    On Error GoTo Data_Error
    Dim data As String
    While Stamp.gotData = True
    data = Stamp.GetData
            Row = Row + 1
            txtStatus2 = "Accepting data for Row " & (Row - 1)
            If Row < 65000 Then
                  Worksheets(1).Range(Chr(65) & CStr(Row)).Value = ReplaceData(data)
            End If
    Exit Sub
    End Sub

    Private Sub clearSheet()
            If Row < 5000 Then Row = 5000
            Worksheets(1).Range("A2:A2" & CStr(Row + 10)).Value = Null
            txtStatus2.Caption = "Cells cleared"
            Row = 1
    End Sub

    If that works as it should then post back here and we will add a time stamp
  • I forgot to mention that the checkbox on the settings form named "Reset on Connect" controls the DTR signal of the serial connection, I don't remember off hand whether DTR should be high or low to enable the RIFD scanner. You may have to toggle the checkbox to enable your RFID.
  • Thank you very much!! :)
  • It sounds like you have it, thats good.

    There are lots of time stamp examples out there this is one that I like.

    It's a formula that is a circular reference so before you add it to your form you will need to modify Excel options.

    Go to Excel Options ----> Formulas and enable the checkbox "Enable iterative calculation" , set the "Maximum iterations" to 1.

    Now add this formula to cell B2.


    Drag it down through column B so that it applies to all the cells in that column, finally set column B's format to the time format you want.

    The last thing you might find useful is a small click event for the DTR checkbox that will allow toggle of DTR even when connected
    Private Sub chkDTR_Click()
    Stamp.DTREnabled = CBool(chkDTR)
    End Sub

    It should work, if not I am sure you can work it out.
Sign In or Register to comment.