Stalling a motor

[Al Skierkiewicz]

Yalib,
I am guessing your real question is lost a little in the translation. If you are asking if you can add a short across the motor to prevent movement, the answer is no that is prevented through the rule...
[R47]
Custom circuits shall not directly alter the power pathways between the battery, PD Board, speed controllers,
relays, motors, or other elements of the Robot control system (including the power pathways to other sensors or
circuits).
The "brake mode" jumper on speed controllers does the same thing, legally. However, the brake is dependent on current flowing in the motor. When the motors are stopped, no current flows so the brake doesn't work either. There are ways you can actively lock the motors via software. This requires some accurate position feedback from the wheels or motors you are trying to lock. Performing a lock through software is legal but only takes place while the robot is enabled.
Electric solenoid actuators are legal this year. You can use them to hold mechanical locking devices (pins as above) out of the drive train and then turn them off to allow a spring return to drop the locking device into place in your drive train.