American Meter Company

David E Campbell

Eric T Kiser

A protocol for utility meter interrogation has a data write portion including: assembling a password transmission sequence having a synchronization string and a message including identification indicia for a select utility meter and a password to activate a select data access level within the select utility meter. This is wirelessly transmitted a first time to a select utility meter. Then, the password transmission sequence is wirelessly transmitted a second time to the select utility meter to confirm the password transmission sequence. A command transmission sequence having the synchronization string and a message including the identification indicia and a write command is assembled to cause the select utility meter to store data in a memory location of the select utility meter corresponding to the data access level activated with the password. The command sequence is then wirelessly transmitted to the select utility meter two times to confirm the command transmission sequence.

Bi-directional protocol

The present invention provides a unidirectional protocol for communicating data from a plurality of utility meters and a meter adapted to carry out this protocol. The meters are adapted to monitor and measure the respective utility parameters which may include those for gas, water, electric or other utilities, and wirelessly download the information to a meter reading device. The protocol basically includes a synchronization pattern followed by the desired information. For a valid transmission, the synchronization pattern and subsequent data are provided in a first transmission sequence, which is immediately repeated after the end of the first sequence. Preferably, a bit is toggled during the retransmission of the transmission sequence for security.

Uni-directional protocol

The present invention relates to a pulse conditioning circuit including a first switch terminal having a first leg connected to a DC power source and a second leg. A second switch terminal is also provided having a first leg connected to an electrical ground and a second leg electrically connected to the second leg of the first switch. Pulses resulting from switch closures at the switch terminals are provided at the node where the second legs of both switch terminals are coupled. This node is preferably coupled to a low-pass filter, which is further coupled to a latch circuit providing a conditioned pulse output. The latch circuit is adapted to provide a first logic state output when the input of the latch is provided with a high logic state and a second logic state output when the input of the latch is provided with a low logic state. The high logic state input is provided when a switch connected to the first switch terminal is closed. Likewise, the low logic state input is provided when a switch associated with the second switch terminal is closed.

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Mountain View, CA, United States of America

David E Campbell