VBA/Access MSComm - Input

Hello,
I have a program in Access that uses VBA to capture data being sent over the serial port from a Cosmo Flow Test Machine. This determines the air pressure's leak rate escaping from a muffler.

I have written several programs that send data out serially, but I am new to "listening" to the port to receive the data.

I can setup an instance of HyperTerminal, provided the settings used in the given manual for the device and successfully retreive data results. When using the same settings in my VBA code, I never get any data; none. The data coming from HyperTerminal seems to be 'stream' based rather than packet, thus I used the code to keep adding the characters to the end until it finishes the loop.

Here's the code:

Code:

---

Private Sub cmdHHP_Click()
 
Dim strLeakRate As String
Dim strUprLmt As String
Dim strLwrLmt As String
Dim strChar As String
 
strUprLmt = 3.77
strLwrLmt = 0
 
lblStatus.Caption = "RETREIVING LEAK TEST DATA"
 
    MSComm0.CommPort = 1
    MSComm0.Settings = "1200,N,8,1"
    MSComm0.PortOpen = True
   
        Do Until strChar = ":"
            strChar = MSComm0.Input
            strLeakRate = strLeakRate & MSComm0.Input
        Loop
       
    MSComm0.PortOpen = False
   
lblStatus.Caption = "DATA RETREIVED"
   
    strLeakRate = Mid(strLeakRate, 6, 11)
    lblLeakRate.Caption = strLeakRate
   
   
             
        If strLeakRate > strUprLmt Then
            cmdFailed
            Exit Sub
        Else
            DoCmd.RunMacro "macHHP"
        End If
       
 lblStatus.Caption = "PRINTING LABEL"
 
'''''''''''
cmdReset
'''''''''''
 
End Sub
 
Public Sub cmdFailed()
 
 MsgBox "Test Failed. Please try the leak test at most 3 times for any one DPF.", vbCritical + vbOKOnly, "LEAK TEST FAILED"
End Sub
 
Public Sub cmdReset()
 
 strChar = ""
 strLeakRate = ""
 lblLeakRate.Caption = "-----"
 lblStatus.Caption = "READY"
 
End Sub

---

Looking at the form versus the code, it doesn't seem like it's preforming the first working line. I have a label that changes status when they click a 'start' button. As soon as the button is clicked, I would imiagine that the display message should change to 'RETREIVING LEAK TEST DATA'.

Another concern is that it doesn't seem like the port is actually ever opening. The code currently hangs in the loop waiting to receive the ":" char to denote the end of the string. I manually break the code and debug, then go back to the form to try again and I DO NOT receive a 'port already open' error as would be expected. However, this may be due to when I debug, and then close the VB editor, it resets the code, thus closing the port.

One last question... The manual claims that the end of the string is denoted by carriage return, <CR>. It lists what I think to be the hexadecimal code for that as (0DH). How would I go about using that as the delimiter to signify the end of the string if the input is stream based (one character at a time)?

Any info anyone could share would be most appreciated.
Thanks in advance,
dbrother