Trending using a Siemens TP270

Does anyone know why it takes so long for Trending data to appear on the screen of a TP270 when you configure a trendview using Simatic Protool ?
It seems to take 5 minutes before the realtime trending starts even though my Pulse time is set to 60 seconds.
Thanks

I use trends a lot on OP170B, OP270-10, and Protool Pro projects.
And I have no problem with it taking a long time to "start".

Have you set up the number of samples for the trend to be the same as the displayed number of samples for the trendview ?