RTD function

This article describes the formula syntax and usage of the RTD function (function: A prewritten formula that takes a value or values, performs an operation, and returns a value or values. Use functions to simplify and shorten formulas on a worksheet, especially those that perform lengthy or complex calculations.) in Microsoft Excel.


Retrieves real-time data from a program that supports COM automation (COM add-in: A supplemental program that extends the capabilities of a Microsoft Office program by adding custom commands and specialized features. COM add-ins can run in one or more Office programs. COM add-ins use the file name extension .dll or .exe.).


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

The RTD function syntax has the following arguments (argument: A value that provides information to an action, an event, a method, a property, a function, or a procedure.):


  • 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.

ShowHow do I copy an example?

  1. Select the example in this article. If you are copying the example in Excel Online, copy and paste one cell at a time.
    Important: Do not select the row or column headers.

Selecting an example from Help

Selecting an example from Help

  1. Press CTRL+C.
  2. Create a blank workbook or worksheet.
  3. In the worksheet, select cell A1, and press CTRL+V. If you are working in Excel Online, repeat copying and pasting for each cell in the example.
    Important: For the example to work properly, you must paste it into cell A1 of the worksheet.
  4. 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.

Formula Description (Result)
=RTD("MyComAddIn.Progid",,"LOREM_IPSUM","Price") Data
Applies to:
Excel 2010, Excel Web App, SharePoint Online for enterprises, SharePoint Online for professionals and small businesses