A process for initializing a motorized roller shutter that moves between two extreme positions includes moving the shutter in a first direction at fast speed, then moving it at slow speed, then reversing it in a second direction at fast speed followed by slow speed. The shutter is moved back in the first direction at fast speed, then at slow speed, after which the times are determined that are needed to cover the full travel at fast speed between the two extreme positions in the first direction and in the second direction.