I want to send data and receive data as string if possible or at least as integer

Question

1. I am trying to send and receive data through mscomm port, but am receiving datatype mismatch.so what should I do to avoid this error, I need to send data as integer and receive it as string if possible ,minimum I should get it as integer datatype. The following is my code, please help me to solve this problem.

2. The send and receive code is working when run independently.

Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub Command1_Click()
    If (MSComm1.PortOpen = False) Then
        MSComm1.PortOpen = True
    End If
    Command1.Enabled = False
    Command2.Enabled = True
    Text3.Text = "COM1, Baud - 9600, Databit - 8, Parity - None, Stopbit - 1....CONNECTED." & Text3.Text
End Sub

Private Sub Command2_Click()
    If (MSComm1.PortOpen = True) Then
        MSComm1.PortOpen = False
    End If
    Command1.Enabled = True
    Command2.Enabled = False
    Text3.Text = "DISCONNECTED" & Text3.Text
End Sub

Private Sub Command3_Click()
    Text1.Text = " "
    Text2.Text = " "
    Text3.Text = "CLEARED" & Text3.Text
End Sub

Private Sub Command4_Click()    
    MSComm1.Output = Text2.Text
    Text3.Text = "SENDING" & Text3.Text
End Sub

Private Sub Command5_Click()
    Text3.Text = " "
End Sub

Private Sub Form_Load()
    MSComm1.CommPort = 1
    MSComm1.Settings = "9600,N,8,1"
    MSComm1.DTREnable = True
    MSComm1.Handshaking = comRTS
    MSComm1.InBufferSize = 2
    MSComm1.RThreshold = MSComm1.InBufferSize
    MSComm1.RTSEnable = True
    MSComm1.InputLen = 2
    MSComm1.InputMode = comInputModeText
    MSComm1.NullDiscard = True
    MSComm1.OutBufferSize = 2
    MSComm1.SThreshold = MSComm1.OutBufferSize    
    MSComm1.PortOpen = True  
End Sub

Private Sub Form_Unload(Cancel As Integer)
    If (MSComm1.PortOpen = True) Then
        MSComm1.PortOpen = False
    End If
End Sub

Private Sub MSComm1_OnComm()
    Dim Buffer As String
    Select Case MSComm1.CommEvent
        Case comEvReceive
            'Text1.Text = " "
            Buffer = Cstr(MSComm1.Input)
            Text1.Text = Buffer
    End Select
End Sub

Answer 1

I think the main problem is that you are sending data asynchroniously without any attempt to transmission control. Since there are multiple characters to be transmitted you need to tell the receiver where a new transmission start to let it find the right offset.

In your case you say you only want to send values in the range 0..100. By using a single byte values in the range 0 to 255 can be addressed so sending a single byte per value to send is sufficient in that case and for a single character no transnission control will be necessary.

Here an example where the number is converted to a single byte, send and reconverted to a number:

Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub cmdOpen_Click()
    If (MSComm1.PortOpen = False) Then
        MSComm1.PortOpen = True
    End If
    cmdOpen.Enabled = False
    cmdClose.Enabled = True
    txtState.Text = "COM1, Baud - 9600, Databit - 8, Parity - None, Stopbit - 1....CONNECTED." & txtState.Text
End Sub

Private Sub cmdClose_Click()
    If (MSComm1.PortOpen = True) Then
        MSComm1.PortOpen = False
    End If
    cmdOpen.Enabled = True
    cmdClose.Enabled = False
    txtState.Text = "DISCONNECTED" & txtState.Text
End Sub

Private Sub cmdClear_Click()
    txtReceived.Text = " "
    txtSend.Text = " "
    txtState.Text = "CLEARED" & txtState.Text
End Sub

Private Sub cmdSend_Click()
Dim Number As Byte
    'some checking - needed depending on source of data
    If Not IsNumeric(txtSend.Text) Then
        MsgBox "only numbers (from 0 to 255)"
        Exit Sub
    End If
    If Val(txtSend.Text) < 0 Or Val(txtSend.Text) > 255 Then
        MsgBox "out of range (from 0 to 255)"
        Exit Sub
    End If

    Number = CByte(Val(txtSend.Text))
    MSComm1.Output = Chr(Number)
    txtState.Text = "SENDING" & txtState.Text
End Sub

Private Sub cmdClearState_Click()
    txtState.Text = " "
End Sub

Private Sub Form_Load()
    MSComm1.CommPort = 1
    MSComm1.Settings = "9600,N,8,1"
    MSComm1.DTREnable = True
    MSComm1.Handshaking = comNone 'comRTS i only got a 3-wire connection - so no handshaking
    MSComm1.InBufferSize = 1024 'not 2 we don't want a buffer overflow THAT fast
    MSComm1.RThreshold = 1 'Raise OnComm-Event if 1 character is in Rx-buffer
    MSComm1.RTSEnable = True
    MSComm1.InputLen = 1 'get one character at a time
    MSComm1.InputMode = comInputModeText 'the Binary mode never worked out for me - even when transmitting binary data
    MSComm1.NullDiscard = False 'also NULL-Characters will be received
    MSComm1.OutBufferSize = 512 'again we don't want overflow
    MSComm1.SThreshold = 0 'don't hold back data - blow them out directly
    MSComm1.PortOpen = True
End Sub

Private Sub Form_Unload(Cancel As Integer)
    If (MSComm1.PortOpen = True) Then
        MSComm1.PortOpen = False
    End If
End Sub

Private Sub MSComm1_OnComm()
    Dim Buffer As String
    Select Case MSComm1.CommEvent
        Case comEvReceive
            'txtReceived.Text = " "
            Buffer = MSComm1.Input
            txtReceived.Text = Asc(Buffer)
            txtState.Text = "RX" + txtState.Text
    End Select
End Sub