Asynchronous tcp client dilemma - vb.net

Question

I am trying to write an asynchronous TCP client with VB.NET to communicate with a thermal printer (Intermec Px4e), but I am facing an issue regarding the way I receive the data from it.
Previously I was using a synchronous client, but I had the problem regarding the response not coming instantly from the printer, so after sending data and then checking for available bytes I was able to read only the first bytes of the response.
This is the synchronous client I am actually using:
Private Function sendBytesEthernet(ByVal data As Byte(), ByVal withResponse As Boolean) As PrinterPacket(Of Byte())
Dim socketStatus As Net.Sockets.SocketError
Dim response As New PrinterPacket(Of Byte()) With {.StatusCode = CommandStatusCode.ERR, _
.Response = String.Empty, _
.Data = data}
Try
If Me.oggettoSocket.Client.Poll(2000, Sockets.SelectMode.SelectWrite) Then
Me.oggettoSocket.Client.Send(data, 0, data.Length, 0, socketStatus)
Else
Throw New Exception(socketStatus.ToString())
End If
If withResponse Then
Dim bytesAvailable As UInteger = Me.oggettoSocket.Available
If bytesAvailable > 0 Then
Dim dataBuffer(bytesAvailable - 1) As Byte
Dim bytesReceived As UInteger = Me.oggettoSocket.Client.Receive(dataBuffer, 0, dataBuffer.Length, Sockets.SocketFlags.None, socketStatus)
If socketStatus = Sockets.SocketError.Success Then
If bytesReceived > 0 Then
response.Response = System.Text.Encoding.UTF8.GetString(dataBuffer)
response.StatusCode = CommandStatusCode.OK
Return response
End If
Else
Throw New Exception(socketStatus.ToString())
End If
End If
End If
If socketStatus = Sockets.SocketError.Success Then
response.StatusCode = CommandStatusCode.OK
Else
Throw New Exception(socketStatus.ToString())
End If
Catch ex As Exception
Select Case ex.Message
Case "ConnectionReset"
Me.oggettoSocket.Client.Disconnect(True)
Me.openSocket()
End Select
response.Response = ex.Message
End Try
Return response
End Function
What happens is that If send a command to the printer that involves a big response from it, I receive the full response splitted in several packets, so with this function I am only able to read the first packet.
For example:
I send to the printer the command to list all the fonts available (FONTS[CRLF])
The printer responds, but it sends the first 54 bytes and then truncates the list.
The printer sends the second packet, this time 1560 bytes long, but it still truncates the list.
Lastly the printer completes the list with last 25 bytes.
Basically with my function I am only able to read the first 54 bytes, unless I don't use a loop to check the availability on the receive buffer in conjunction with a Thread.Sleep() call, since the client is synchronous and I have to wait for the printer to send every packet, but I find this method really inefficient.
At this point I concluded that I had to move to an asynchronous approach, due to the nature of the TCP protocol. I copied an example of async client on the MSDN and it works, but it doesn't fit my use case. Why?
Because I actually have a thread that constantly communicate with the printer through the socket, and I open the connection when the thread starts and close it when the thread ends. If use, for example, the BeginReceive callback used in the MSDN example, that call will never end until I close the connection client side. This cannot take place, since I keep the connection open to the printer and I can't establish a new TCP connection for every thread cycle (that would be a waste in terms of network traffic).
I hope I have explained the problem well.