Receiving data on serial port not doing as expected

[DataMiser]

It is pretty simple, assuming you buffer the incoming data with a staic var as shown above then once you add the latest data to the var you would check to see if that terminator character exists in the string. If so parse the string and process the data up to the CR then leave any additional data that may be present in the buffer

Static InBuffer As String
Dim Transaction As String, Pos As Integer

InBuffer = InBuffer & MSComm1.Input

Pos = InStr(InBuffer, vbCr)
If Pos > 0 Then
    Transaction = Left$(InBuffer, Pos - 1)
    Debug.Print "Transaction=" & Transaction
    If Len(InBuffer) > Pos  Then
        InBuffer = Mid$(InBuffer, Pos + 1)
    Else
        InBuffer=""
    End If
End If