| 摘要 |
A user input device, e.g., a wireless keyboard, for providing user inputs to a receiver unit via a communications medium intermittently transmits diagnostic messages in the communications medium such that a diagnostic message is transmitted after a predetermined interval following transmission of a preceding diagnostic message has expired. A receiver unit is responsive to the communications medium and configured to receive the transmitted diagnostic message and process the received diagnostic message to determine a status of the user input device. Preferably, the user input device is configured to transmit a diagnostic message following at least one of passage of a predetermined fixed time interval after a diagnostic message was previously transmitted from the user input device and acceptance of a predetermined number of user inputs at the user input device after a diagnostic message was previously transmitted from the user input device. |
