we apologize for the delay from the last e-mail, but only yesterday we have been in the plant and could do the test what You told us last time.
In the last week, due to hardware problems, we formatted the server and the client, installed and riconfigured everything (top server, opc client, etc.) in our office (i.e. outside our customer network).

In our office the DCOM configuration were performed and worked fine, both on the server and the client; we used OPC Expert and EasyDemo to read data from TopServer and everything worked fine; also our traceability application worked fine
Yesterday our customer joined the pc server to his network; the pc client is connected to the server on a subnet (the server has two Ethernet boards). After that we had some problems when pc client reading data from Top Server:

OPC Expert could read data but gave the message " OPC Rescue was able to connect to server and could start ToolBox OPC Power Server 5.7 but could not complete the connection. Cause: this is likely because the following separates ToolBox OPC Power Server from this computer:
- NAT with "aggressive filtering"
- The Internet.

Suggested actions:
- connect this computer to Toolbox OPC Power Server using a VPN
- Remove the NAT appliances "

The IT specialist told us that there is no NAT configured and we would like not to use a VPN.

In our Application (using Quick OPC Classic 5.1 to get data from Toolbox OPC Power Server 5.7.84.23) raised the exception:

OpcLabs.EasyOpc.OpcException: OPC operation failure ---> System.Runtime.InteropServices.COMException (0x80070776): the specified exporter object doesn’t exist.
in OpcLabs.EasyOpc.DataAccess.EasyDAClient.CheckComResult(Int32 hResult, IErrorInfo* pErrorInfo)
in OpcLabs.EasyOpc.DataAccess.EasyDAClient.ReadItemValue(ServerDescriptor serverDescriptor, DAItemDescriptor itemDescriptor)
in PLCManager.PLComunication.readSingleItemValue(DAItemDescriptor itemDescriptor) in C:\PLComunication.cs:riga 465 readSingleItemValue

On the server there is no firewall.

We are confident that this problem derived from our customer’s network policies (because in our office everything worked fine); so we asked out customer’s IT specialist to investigate on the message from OPC Expert but they were not able to solve it.

So can You please help us to find the real origin of the problem ? could You tell us, with some details, what verify in the network policies to remove the error on the client ?

Any suggestion is really appreciated.

We hope to hear from You soon.

Thank You very much.

The last year we developped a Traceability application (Windows XP) in an Italian plant of our customer (automotive) and we used “QuickOPC-Classic 5.1” to get data from the Top Server.
We bought the developer+runtime license.

This year our customer migrated to Windows 7 64-bit and required an upgrading of the same application using QuickOPC 5.23 (based on Microsoft DCOM).

We have 2 questions:

1) DCOM Configuration
We got the procedure from www.softwaretoolbox.com/dcom/html/configuring_dcom.html
The procedure works well on Windows XP but doesn't work on Windows 7; we have tried it almost 20 times (both on client and server) but every time, when we use EasyOPC.NET Demo Application on the client to test data acquisition from Toolbox OPC Power Server 5.7 (which is on a separated server), we get the HRESULT Exception: 0x80040202.
Could You please indicate us the correct procedure ?
in the meanwhile it is impossible for us to release upgrated application to our customer.

2) is it possibile to get an upgrading of the upper license to work with QuickOPC 5.23 ?

Any help is appreciated.

Thank You very much.