Transmitter unit and control unit

摘要

Methods and apparatus that implement a transmitter unit and a control unit to alert a user if the control unit is beyond a limited range of communications. A method of alerting a user that a transmitter unit is beyond a limited range of communicating wirelessly with a control unit may include, wirelessly transmitting a radio frequency signal from the transmitter unit to the control unit, determining at the control unit whether the transmitter unit is beyond the limited range of wireless communications, and selectively generating an alert at the control unit based on a result of the determination. Determining at the control unit whether the transmitter unit is beyond the limited range of wireless communications may include detecting an occurrence of a predetermined condition.