c# RTD Server, IRTDUpdate Object
 

I'm trying to implement a RTDServer for Excel in C#. How can I cause
Excel to update my data?
I tried to call the UpdateNotify function on the IRTDUpdateEvent
Object, but nothing happened.The reference to the IRTDUpdateEvent does
not work. I can't even change the HeartbeatInterval. The
Microsoft.Office.Interop.Excel.IRtdServer.RefreshD ata function is never
called. ServerStart, ConnectData, DisconnectData, ServerTerminate are
properly called by Excel.
Is there something wrong with the reference to the IRTDUpdateEvent
object?

int
Microsoft.Office.Interop.Excel.IRtdServer.ServerSt art(Microsoft.Office.Interop.Excel.IRTDUpdateEvent
CallbackObject)
{
// GUI to show debug messages
output.write("ServerStart | " +
CallbackObject.HeartbeatInterval);

//Hold a reference to the callback object.
update_event = CallbackObject;

// does not work!
update_event.HeartbeatInterval = 500;
// HeartbeatInterval is still 15000

output.write(" update_event HeartbeatIntervalll: " +
update_event.HeartbeatInterval);

return 1; //SUCCESS
}


It seems that I cannot access the IRTDUpdateEvent.
Any ideas?

Thanks

Heribert