WD2000: Run-Time Error 5584 "Too Many DDE Channels Are Open..." (201991)

CAUSE

When using DDE to communicate between programs, a separate "channel" or line of communication for each DDE conversation is created. It is possible to have multiple DDE conversations happening at the same time. While there is no absolute limit to the number of DDE conversations that can exist simultaneously, there is a relative limit that depends on the amount of system resources available. This limit varies from system to system.

WORKAROUND

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To prevent the error message from appearing, terminate each DDE conversation after you are finished using the channel. To terminate a DDE channel, use either of the following commands.

Syntax to Terminate a Specific Channel Number

   DDETerminate(ChannelNumber)

Syntax to Terminate All DDE Channels

   DDETerminateAll

For example, the following macro (Sub procedure) uses DDETerminate to close each DDE channel that is initiated.

   Sub DDETest
      For x = 1 to 40
         chan = DDEInitiate("Excel", "Sheet1")
         ' Your other commands go here.
         DDETerminate chan
      Next x
   End Sub

To reproduce the "Session too complex...." error message, start Word and Excel and run a macro that opens a number of DDE channels without terminating the channels.

   Sub DDEReproduceError
      For x = 1 to 40
         n = DDEInitiate("Excel","Sheet1")
      Next x
   End Sub