A medical device system includes a medical device configured to be carried by a patient and a plurality of controllers capable of controlling operation of the medical device. Each controller has an active state in which the controller is in communication with, and controls the operation of, the medical device, and a passive state in which the controller is not controlling operation of the medical device. At any given time only one of the plurality of controllers will be in the active state and a remainder of the plurality of controllers will be in the passive state. The active controller may be configured to continually communicate with the remainder of passive controllers, without using the medical device as an intermediary, to update the information stored in the memories of the passive controllers to match the information in the memory of the active controller.
