How does Excel RTD invoke IRtdServer.DisconnectData()?

Question

It's easy enough to invoke ConnectData() with =RTD() in Excel.

But there's also a function DisconnectData(). Is there some Excel function that will cause DisconnectData() to be called?

What is this method for, really?

Answer 1

When you delete the RTD() call in all cells that reference that topicID, DisconnectData() gets called.

So obvious in retrospect.