What is DDE?

Note: Before Aspen DDE will work correctly in Windows 95, you must install the Microsoft Service Pack for Windows 95. You can download this file from Microsoft, the Aspen BBS, or from Aspen's Internet FTP Site (Download SERVPAK.ZIP from the /cust directory; username is user; password is 747).

One advantage of the Windows version is its capability to link market data to other Windows®-based applications. The program supports dynamic data exchange (DDE). In this discussion, the term server refers to the program’s instrument serving as a link’s data source. The term client refers to the application receiving the information.

As Aspen receives data, it checks all links. If IBM’s last price is linked to an Microsoft Excel® spreadsheet, Aspen updates its database and passes the price on to Microsoft Excel®. You can use linking when you need to view real-time information in Aspen and a spread sheet program because, with linking, Aspen cascades data into one or more client applications. The advantages of linking include:

Many client applications can be updated by changing one Aspen link.

Windows applications that do not support Object Linking and Embedding (OLE) do support DDE.

The disadvantages of linking include:

Links between the Aspen and client applications may be broken if the Aspen’s file names or path names are changed or deleted.

Automatically updated links may slow down Windows® operation.

The program enables you to link data on an instrument, information in a quote window, or information in a chart window to other applications.

Instrument links provide the most robust means of object linking. Any quote code can be piped, with a specific instrument, to another application.

Instruments can also be created in Excel and piped to Aspen.

Topics:

Accessing DDE

DDE Link Syntax

Using the Link Generator

What is an Excel Array?

Passing Data to Aspen

Automatically Updating Aspen Datafiles with Excel Data

Creating a Symbol Using DDE