Accesing a class with properties from another class returns null values - vb.net

Question

I am making an application that reads values from a meter that is connected to my computer via a serial cable. When i press a button i send a command to the meter and after a few miliseconds i get a response back from the meter with the answer.
I am saving these values to a class that has properties init, so that i can access these values from anywhere.
So my problem is that when i try to get the values back it returns a 'nothing value', and its probably from the initialization i have that has a 'New' like this'Dim clsSavedValues As New clsSavedValues', so when i try to get the values from that property class i create a new instanse and that instanse is empty if am not mistaken.
Ill post the code below but here is how the code flows:
I have 3 classes. MainClass, ProtocolClass, PropertiesClass.
From main i call a method inside ProtocolClass, and that method sends a command to the meter. after a few miliseconds i get a call back inside ProtocolClass anf this method is called 'Private Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort.DataReceived' and it saves that return value to the PropertiesClass.
And after the DataReceived method is finished i go back to the MainClass and call another method to get the values from the PropertiesClass that i just saved but they return null. I know they are saved correctly because i can access them if i call them from within the ProtocolClass. But they are null from MainClass.
Here is my code:
MainClass
'Here i call the ProtocolClass
Private Sub btnGetLastTransaction_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGetLastTransaction.Click
clsProtocol.GetLastTransaction(1, Integer.Parse(tbxTransactionPosition.Text))
End Sub
'Here i try to read the valies from PropertiesClass
Public Sub RetrieveMeterSerialNumber()
Dim clsSavedValues As New clsSavedValues
lblMeterSerialNumber.Text = clsSavedValues.SaveMeterSerialNumber
End Sub
ProtocolClass
Public Sub GetLastTransaction(ByVal destinationAddress As String, ByVal transactionNum As Integer)
clsSavedValues = New clsSavedValues 'Creating Instance of the properties class
Try
Dim v_bodyOfMessage As [Byte]() = {ASCIItoHEX("G"), _
ASCIItoHEX("r")}
Dim v_bytearray As [Byte]() = ConstructCommand(v_bodyOfMessage)
SendCommand(v_bytearray)
Catch ex As Exception
Console.WriteLine("Meter serial number button click exception: {0}", ex)
End Try
End Sub
Private Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort.DataReceived
If comOpen Then
Try
ReDim rx(rxPacketSize)
Console.WriteLine("RESPONSE")
For i = 0 To rxPacketSize - 1
readByte = SerialPort.ReadByte.ToString
Console.WriteLine(i.ToString & ": " & Conversion.Int(readByte).ToString)
rx(i) = Conversion.Int(readByte).ToString
If i <> 0 Then
If Convert.ToByte(rx(i)) = vDelimeterFlag(0) Then Exit For
End If
Next
DecodeResponse()
Catch ex As Exception
MsgBox("SerialPort_DataReceived Exception: " & ex.Message)
End Try
End If
End Sub
Private Sub GetMeterSerialNumber()
Dim i_startPosition As Integer = 5
Dim meterSerialNumber As String = GetRemainingPortionOfString(i_startPosition)
clsSavedValues.SaveMeterSerialNumber = meterSerialNumber
frmExplorer.RetrieveMeterSerialNumber() 'This is the call to the main class
End Sub
PropertiesClass
Public Property SaveMeterSerialNumber() As String
Get
Return _MeterSerialNumber
End Get
Set(ByVal meterSerialNumber As String)
_MeterSerialNumber = meterSerialNumber
End Set
End Property
I want to get the values from the PropertiesClass because ill get more than wan response from the meter and that causes thread issues and i cannot keep track with them. So i save the values in one class and then i want to access them all from that class.
Sorry for the long post, ask me anything you want for clarification

Answer 1

clsSavedValues in SerialPort_DataReceived() and in your Main Class RetrieveMeterSerialNumber() are two different objects (with same variable names but each 'new' create a new instance of clsSavedValues ) maybe you should pass the clsSavedValues var from protocol to Main as parameter.
Main :
Public Sub RetrieveMeterSerialNumber(clsSavedValues As clsSavedValues )
lblMeterSerialNumber.Text = clsSavedValues.SaveMeterSerialNumber
End Sub
Protocol :
Private Sub GetMeterSerialNumber()
Dim i_startPosition As Integer = 5
Dim meterSerialNumber As String = GetRemainingPortionOfString(i_startPosition)
clsSavedValues.SaveMeterSerialNumber = meterSerialNumber
frmExplorer.RetrieveMeterSerialNumber(clsSavedValues) 'This is the call to the main class
End Sub
or use a static property in your PropertiesClass