@DDEInitiate (Formula Language)

Initiates a conversation with a DDE server, and returns the conversation ID.

Note: DDEInitiate is not supported by UNIX™ or on the Macintosh.

Syntax

@DDEInitiate( application ; topic )

Parameters

application

Text. The name of the application you want to initiate a DDE conversation with. This application must be launched before you call @DDEInitiate. The values for application and topic vary from one application to another; the appropriate values can usually be found in the index for the application's documentation, under "DDE."

topic

Text. The data file you want to use. This file must be opened before you call @DDEInitiate.

Return value

conversationID

This ID identifies the particular DDE conversation so you can pass commands and data to it with @DDEExecute and @DDEPoke, and eventually terminate the conversation with @DDETerminate. Returns an error if the conversation cannot be initiated. See @IsError.

Usage

It is intended for use primarily in field formulas, agents, and toolbar buttons. Since the Macintosh does not support DDE, these commands will not work on Macintosh workstations. This function does not work in column or selection formulas, and is not intended for use in window title or form formulas.

If the user's notes.ini file includes the statement

NoExternalApps=1

then any formula involving @DDE functions is disabled. The user doesn't see an error message; the formula fails to execute.

You can have up to 10 DDE conversations running concurrently, although under normal circumstances you should only have one conversation running at a time. Be sure to terminate all DDE conversations once they're completed, or you may run out of sessions and be unable to initiate more conversations when needed.

You cannot use this function in Web applications.

Initiation failures

If the conversation cannot be initiated, @DDEInitiate will return an error. See @IsError. Below are some reasons why the initiation could fail:

  • The workstation operating system does not support DDE (Macintosh).
  • The DDE application you're trying to set up a conversation with is not running. The specified file is not open.
  • The DDE application is running, but the specified topic is not open or the application does not support the topic specified with @DDEInitiate.
  • The DDE application is running, but the specified file does not open.
  • The maximum number of concurrent DDE conversations has been reached (currently, the maximum is 10).

Examples

See @DDEExecute.