A method performed in an electronic device that connects via a USB connector to an accessory that supports multiple different operating modes. The method comprises: in response to successful authentication of the accessory after an initial connection, configuring an accessory usage setting of the electronic device to correspond to the accessory's default operational mode. In response to a request to change the operational mode of the accessory to a second operational mode: communicating to the accessory, over the signal/communication lines of the USB, mode identifying information corresponding to the second operational mode; generating a voltage level change on an ID line of the USB connector to communicate to the accessory that a change in the accessory's present operational mode is being triggered, where the accessory is designed to change to the second operational mode when a pulse or voltage level change is detected on the ID line.