VBA Subroutine doesn't exit for loop

Question

I’m new to programing so I’m hoping you can help me. Not sure how to formulate the right question so I didn’t find any StackOverflow answers.

When I step through this code and come to OpcServObj.Connect OpcServerStrg it doesn't connect. I get no errors, nothing appears to happen. Cursor jumps to the left margin and does nothing. Only when I resume stepping through the routine it starts the function over again. It should continue and exit the for loop where I plan to test the state of the connection again.

Reference Library: OPC DA Automation Wrapper 2.02

Sub Main()
ConnectOPC
End Sub

Private Function ConnectOPC() As Boolean

Dim OpcServObj As OPCAutomation.OPCServer            
Dim OpcGroupObj As OPCAutomation.OPCGroup            

Dim OPCServerlist As Variant
Dim OpcServerStrg As String

Set OpcServObj = New OPCAutomation.OPCServer          
OPCServerlist = OpcServObj.GetOPCServers

If OpcServObj.ServerState <> True Then

    For i = 1 To UBound(OPCServerlist) 

       OpcServerStrg = OPCServerlist(i)

         If OpcServerStrg = "ICONICS.IconicsOPCUAServer.V5" Then

            OpcServObj.Connect OpcServerStrg

            Exit For

         End If

    Next i

End If

End Function

Thanks

Answer 1

At the line:

If OpcServerStrg = "ICONICS.IconicsOPCUAServer.V5" Then

if the value in the variable OpcServerStrg is not equal to "ICONICS.IconicsOPCUAServer.V5" then the code will loop again to the top of the For loop and execute OpcServerStrg = OPCServerlist(i) again. The Exit For will not be seen.

When you say you step through this code... is it possible that you have a breakpoint set on the line: OpcServerStrg = OPCServerlist(i), and you are clicking run (untill breakpoint) instead of clicking to single-step through the code?

Try setting a breakpoint at the line:

If OpcServerStrg = "ICONICS.IconicsOPCUAServer.V5" Then

then examine the value of OpcServerStrg when the program reaches the breakpoint and stops.