Using MSComm control

[jhenry]

Hello!

I am trying to write a program that communicates with a device through Com port 2. I found a VB6 program that communicates with it fine ... but after using the same methods in .NET I couldn't get it to work. It looks like the OnComm event is never even triggered ... I wrote a really simple class to send a command to the device and then display a message that lets me know the OnComm event has been activated ... I'm not getting any response. Can anyone help?

Here's the little test program I wrote:

Public Class Form1
Inherits System.Windows.Forms.Form

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim Instring As String

Comm2.CommPort = 2

Comm2.Settings = "9600,N,8,1"

Comm2.InputLen = 0

If Comm2.PortOpen = False Then
Comm2.PortOpen = True

End If
End Sub


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Comm2.Output = "SVAA" & Chr(13)

End Sub


Private Sub Comm2_OnComm(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Comm2.OnComm

Select Case Comm2.CommEvent
Case MSCommLib.OnCommConstants.comEvReceive
Dim Buffer As VariantType
Buffer = Comm2.Input

Label1.Text = "On Comm Active"

End Select

End Sub

End Class

[grahamxyz]

In answer to your other quiry I suggested that you use a timer to read the comm port into a string. you can manage the string from there. I have never tried the oncomm event but using the timer to read the input buffer into a string works fine.