How to use an Excel RTD server with DCOM

Microsoft Office Excel 2007, Microsoft Office Excel 2003, and Microsoft Excel 2002 provide a new worksheet function that is named RealTimeData (RTD). RTD lets you call a Component Object Model (COM) Automation server for retrieving data in real time. This RTD server can exist as an ActiveX DLL or as an .exe that runs on the same local computer or on a remote server. When the RTD server runs on a remote server, the RTD server uses DCOM to communicate with Excel.

Note When RTD server runs on a remote server, the RTD server must be an .exe.

This article describes how to configure DCOM on both the remote server and on the local client computer to enable this functionality.

Configure DCOM on the remote server

1. Register the RTD server on the computer that will serve as the remote server. Note that Excel must be installed on both the remote server and the local client computer.
2. On the taskbar, click the Start button, click Run, type Dcomcnfg.exe, and then click OK to start the DCOM configuration utility.
3. On the Default Security tab, edit Default Access Permissions and add any users that are permitted to access the RTD server. For a public RTD server, add Everyone to allow anonymous access to the RTD server. Set Type of Access to Allow Access.
4. Add the same entries to the Default Launch Permissions list, and set the Type of Access to Allow Launch.
5. Add the same entries to the Default Configuration Permissions list. For most RTD servers, setting the Type of Access to Read should be sufficient. For RTD servers that use the registry to store settings, it may be necessary to set the Type of Access to Full Control.

Configure DCOM on the local client computer

1. Register the RTD server on the local client computer. For Excel to request the RTD server on the remote server, only the ProgID and CLSID need to be registered.
2. Run Dcomcnfg.exe on the local client computer.
3. On the Default Security tab, edit the Default Access Permissions, and add the Everyone account. The RTD server must make calls to Excel to notify it when new data becomes available. Because of a feature of Windows security, the so-called "One Hop Rule," the RTD server makes its call back to Excel as an anonymous user. If the Everyone account is not listed under Default Access Permissions, the RTD server is unable to communicate with Excel, and RTD formulas in Excel return #N/A.

After you configure the RTD server on both the local client computer and the remote server, start Excel on the local client and enter the RTD function into a cell on a worksheet. Use the second parameter of the RTD function to specify the remote server on which the RTD server is installed:

For more information about Excel and RTD servers, click the following article number to view the article in the Microsoft Knowledge Base: