Re: Serial Port / RS232

Sorry! Nevermind. I jumped the gun here. My scanner was set up with a Preamble to send a <CR> and my Postamble was DISABLED. Now that I've fixed those, I also removed the vbCrLf in my ReceiveSerialData. Everything works great.



"Tony K" <king-tony2@xxxxxxxxxxxxxxxxx> wrote in message news:1F350BB0-6EF7-4BE7-B91E-99E26A0A844B@xxxxxxxxxxxxxxxx
I have a slight problem. When attempting to receive data via my serial port I sometimes do not get the complete data. For example, I have a scanner that reads barcodes. When reading barcode after barcode, there might be 2 or 3 barcodes in a row where I do not get the complete barcode. It will be split up over 2 lines.


Here is my code and an example of the data received is toward the bottom.

Dim WithEvents com1 As New SerialPort

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Try
With com1
.PortName = "Com4"
.BaudRate = 9600
.Parity = Parity.None
.DataBits = 8
.StopBits = StopBits.One
End With
com1.Open()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub

Private Sub com1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles com1.DataReceived
Dim returnStr As String
returnStr = com1.ReadExisting 'ReadLine does not work. Any reason why??
ReceiveSerialData(returnStr)
com1.DiscardInBuffer()
End Sub

Sub ReceiveSerialData(ByVal msg As String)
' Receive strings from a serial port.
CheckForIllegalCrossThreadCalls = False
TextBox1.Text &= msg & vbCrLf
End Sub

I cannot find anything about an EOM (End Of Message) character setting for the Serial Port. My scanner is set up to send <CR><LF> at the end of each scan.

Here is an example of the data that I receive. I scanned 2 barcodes over and over. You can see the barcodes are split up but I'm not sure what is causing this. Any suggestions would be greatly appreciated.

036600826313

04740
0097742

036600826313

047400097742

036600826313

0474
00097742

036
600826313

047
400097742

036600826313

04740009
7742


Thank you all,
Tony

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