On some controller we can fit, at the factory, a ‘braking’ light driver. This braking light option replaces the standard parking brake driver.
On road vehicles a brake light may be required. If the vehicle has regenerative braking, then it is natural to ask for the controller to operate a light when it is braking.
Unfortunately this is not as easy as it sounds. This is because braking in most controllers is done automatically by the motor speed and nothing in the controller changes state in any way that can be simply detected.
So, in the Pro-120, the light is operated when the controller is ramping the speed down, i.e, decelerating.
The 4QD series do actually switch states during braking, so here the light driver actually indicates that regenerative braking is occurring.