Troubleshooting DDE

The following sections address some of the problems that may occur when using DDE.

Important

Starting with Windows Vista, Microsoft does not support DDE on a network anymore. However, you can create DDE links on a local computer.

In This Topic

DDE is slow
A link for this server-topic-item already exists
Circular links
Data are not updated

DDE is slow

Minitab is a robust DDE server, suitable for use across a wide range of applications. However, several factors outside Minitab might limit DDE performance, including the following:

The general performance of DDE in Windows
The memory limitations and general performance of your computer
The number and size of other applications that are running
The performance of DDE in other applications

Minitab queues transfers that it cannot process immediately. Minitab then processes queued transfers in priority order. If you need to improve DDE performance, try the following:

Prioritize your most important DDE updates. To change priorities for links, choose Edit > Worksheet Links > Manage Links, select the link to change, then click Change. In Priority, enter a new priority.
Use a more powerful computer to run the applications.

A link for this server-topic-item already exists

Each link name (the combination of application, topic, and item names) must be unique. For example, you cannot have two links that each have the name excel mydata.xls R1C1:R20C2.

Change the new link to make it unique, or remove the original link.

Circular links

Circular links occur when Minitab receives and sends DDE data at the same time, and when the data being received directly or indirectly refers to the data being sent. Circular links can loop indefinitely and occupy system resources. However, sometimes a link that triggers a circular link error message is not truly circular.

If you know the link is circular, stop the update by pressing Ctrl+Pause or Ctrl+Break.
After several identical updates, Minitab may identify the link as circular. If Minitab detects a circular link, it prompts you to ignore external requests and updates.
- Click Yes to stop the current DDE transaction and change your Minitab preferences to ignore DDE updates and requests. All DDE transactions are disabled until you change your DDE preferences to enable updates and requests. For more information, go to Stop or start DDE transactions and remove DDE links and see the section "Globally stop and start DDE transactions".
- Click No to stop the current DDE transaction.
Do one of the following:
- Remove the circular link. For more information, go to Stop or start DDE transactions and remove DDE links and see the section "Remove DDE links".
- Change the anchor column to make it non-circular. For more information, go to Create or change a DDE link in Minitab.

Data are not updated

The following conditions cause Minitab to stop updates and to queue incoming data from DDE links:

Input, such as partially typed commands or data values, is unresolved.
Other commands or macros are executing.
The name of the worksheet has changed, so the link is not valid.

Minitab transfers any queued data after these conditions end.