Abstract: A method and apparatus for facilitating data exchange between a utility meter and a host device includes a first wireless interface device coupled to the meter via a first hardwired connection and a second wireless interface device coupled to the host device via a second hardwired connection. The first wireless interface device and the second wireless interface device are operative to wirelessly exchange data therebetween. According to one embodiment, gateway software is provided within the first wireless interface device to allow the first wireless interface device to initiate on behalf of the host computer a request for the meter to provide predetermined information, acknowledge on behalf of the host computer receipt of data containing the predetermined information, purge data containing the predetermined information of information unrelated to the predetermined information and encrypting and decrypting packets exchanged between the meter and host computer.

Abstract: A method and apparatus for facilitating data exchange between a utility meter and a host device includes a first wireless interface device coupled to the meter via a first hardwired connection and a second wireless interface device coupled to the host device via a second hardwired connection. The first wireless interface device and the second wireless interface device are operative to wirelessly exchange data therebetween. According to one embodiment, gateway software is provided within the first wireless interface device to allow the first wireless interface device to initiate on behalf of the host computer a request for the meter to provide predetermined information, acknowledge on behalf of the host computer receipt of data containing the predetermined information, purge data containing the predetermined information of information unrelated to the predetermined information and encrypting and decrypting packets exchanged between the meter and host computer.

Abstract: An interface unit interposed between a central alarm panel and a string of smoke detectors interconnected by a three-wire bus. Two wires of the bus carry AC power and the third wire is an interunit signalling wire. When an individual detector senses a smoke condition, it places a voltage on the signalling wire. The other detectors sound their alarms upon detecting this voltage. The interface unit senses this voltage and notifies the central alarm panel, with the sensing circuitry having a variable high input impedance and being powered solely from the signalling wire. The interface unit includes a test button which, when actuated, disables communications to the central alarm panel for a predetermined period of time. During this time, the interface unit places a periodic signal on the signalling wire, which causes all of the detectors to "beep" while that signal is present. The interface unit also senses the absence of AC power on the bus for notifying the alarm panel of such AC power failure.