Here's an explanation from colintornado - Benelliforum -, posted 27 Sep 2007

My RS does not stall,(1350rpm idle) but if stalling is a problem, there are a few things to consider.

0) the throttle bodies should be balanced before doing anything!
1) When a new map is installed etc, the throttle position sensor should be checked to confirm that is on "0" when shut, and reset it if required.
2) The stepper setting should then be checked to see that it is on 30-40 on idle (tre900).
3) When the CO (carbon monoxide) is set (1 - 3 %) {1% = veggies; 3% = meat eaters (IUSWIM)}, then the stepper must be rechecked to see that it is still within the limits. If not, it can be adjusted back correct.
If it is low it may be that the injector body valves are set open more than they should be.
If they are set right the stepper will be correct.

The stepper position is important.

All of this is part of the normal maintainance procedure, and is in the manuals if you want a read up.
There could be faults on the tps or a sticky stepper etc... that would also cause stalling etc.... then again if everything was perfect we would only get bored!

Stepper Operation At Power Up And Power Down

(BTW. If you can't see the video, you need to update your browser)
It starts partially open, and moves to fully open when powered up.
At power down, the stepper closes fully and continues attempting to step - you can hear it if you listen carefully. This is the ECU making sure that the stepper has hit the stop. It then reverses off of the stop a fixed number of steps, and the ECU powers down. In this way, the ECU always starts from a known position.
This is the cold operation for my Tornado (Sagem ECU), but I'm pretty sure it does the same thing when warm.