Electronic electricity meter

In many electronic electricity meters, communications with a meter microcomputer can be performed via an optical port or an option board connector. For example, in some known meters, an electrical connector is provided so that various option boards, such as a telephone modem communication board, may be electrically connected to the meter microcomputer. A central computer is often used to collect data, including billing information, from the meter, using the modem communication board. The data is available from the modem communication board in a predefined format (an ANSI defined protocol) on the communication channel which connects the option board connector to the meter microcomputer. An electronic electricity meter which, in one embodiment, includes a modem board, or unit, coupled to the meter microcomputer and exchanges information between the meter and a central computer is described. Using signals supplied by the meter microcomputer and the central computer, the modem unit microcomputer can determine whether to exchange information between the meter and the central computer and the proper time at which the information should be exchanged. In an exemplary embodiment, the modem unit detects various conditions within the meter and responds by exchanging information with the central computer at a proper, or pre-defined, time. The modem unit has two different basic modes, or states, of operation. These states of operation are sometimes referred to as the call originate mode and the call answer mode. Call originate refers to the mode of the unit when a condition occurs in meter and information is being transmitted to the central computer from the modem unit utilizing a telephone line. The call is originated upon occurrence, for example of a power outage to the meter. In the call answer mode, the central computer originates a call to the meter. The central computer can then transfer information to the meter, for example a new program can be stored in the modem unit memory.