RTD function

This article describes the formula syntax and usage of the RTDfunction in Microsoft Excel.


Retrieves real-time data from a program that supports COM automation.


RTD(ProgID, server, topic1, [topic2], ...)

The RTD function syntax has the following arguments:

  • ProgID    Required. The name of the ProgID of a registered COM automation add-in that has been installed on the local computer. Enclose the name in quotation marks.

  • server    Required. Name of the server where the add-in should be run. If there is no server, and the program is run locally, leave the argument blank. Otherwise, enter quotation marks ("") around the server name. When using RTD within Visual Basic for Applications (VBA), double quotation marks or the VBA NullString property are required for the server, even if the server is running locally.

  • Topic1, topic2, ...    Topic1 is required, subsequent topics are optional. 1 to 253 parameters that together represent a unique piece of real-time data.


  • The RTD COM automation add-in must be created and registered on a local computer. If you haven't installed a real-time data server, you will get an error message in a cell when you try to use the RTD function.

  • When the server has been programmed to continually update results, unlike other functions, RTD formulas will change when Microsoft Excel is in automatic calculation mode.


The example may be easier to understand if you copy it to a blank worksheet.

How do I copy an example?

  1. Select the example in this article.

    Important   Do not select the row or column headers.

    selecting an example from help

    Selecting an example from Help

  2. Press CTRL+C.

  3. In Excel, create a blank workbook or worksheet.

  4. In the worksheet, select cell A1, and press CTRL+V.

    Important   For the example to work properly, you must paste it into cell A1 of the worksheet.

  5. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

After you copy the example to a blank worksheet, you can adapt it to suit your needs.


Description (Result)



Applies To: Excel 2010, Excel Online, SharePoint Online

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