What is a dynamic data exchange?

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Dynamic Date Exchange (DDE) is a Microsoft® computer protocol that allows you to replace data between applications running in Windows operating systems. More generally as intermediate communication, dynamic data exchange sends messages to create a "conversation" and communication channel between the application requiring data, client and applications where data is located, ie server. The DDE request consists and initiated by the client application, consisting of the application name DDE server , the nature of the data to be replaced, called the DDE , and the name of the dde . DDE links can be carried out once or updated dynamically, in which case the recipient is announced every time you change the value of the entered data on the server application. Multiple DDE links can be created from a lean application, and the application can act as a client and server at the same time. IC data is broadcast by broadcasting messages containing DDE requests to all other running applications. If the applied appsACE recognizes DDE's requirement, reacts and conversation is determined. The Windows operating system then creates a connection between the two applications. Communication channels can be one -off or permanent in cases where the client application must regularly update data. There are two types of permanent links: warm and hot. Warm links first ask the user's approval to update the client application. With hot links, this is done automatically.

Data Communications takes place behind the scenes, ie the user can continue what he does, while the DDE application is carried out in the background. As such, the communication of dynamic data exchange is asynchronous. The DDE request and its result can be stored with shared memory, while clients and server applications continue to process until the request and answer can be active.

This protocol has been replaced to some extent by interconnection andInserting Microsoft® Connection and Inserting (Ole) and Component Object (COM), as well as the Dynamic Data Exchange Management (DDEML) library. However, DDE is still widely used for certain purposes, especially those that do not require continuous use of users. The examples include the Client Microsoft® Excel table update from server applications that receive real -time data from sensors or other measuring devices on a production line that refers to applications that receive real -time stocks and other financial market updates, or regularly update the database table.