How to confirm that the instrument has been triggered？

I am using the E5052B now, I now need to use the "Average Trigger" to trigger, but it takes too long. I don't know how long I have to wait before I do the next step, so I want to determine if the instrument has been triggered.
I didn't find a way to determine if it was triggered in the manual.
So how do I know that the instrument has been triggered? Via GPIB or VISA.