Abstract: A remote meter reading system (10) includes a group of meter interface units operable in an inactive state and periodically activated to monitor a communication channel for activity. Each meter interface unit (12) is responsive to communication signals from a meter reading device (15). The meter reading device (15) initiates communication with a first meter interface unit (12) selected from the group. The meter reading device (15) transmits to the first meter interface unit, a first message including a request for data. The meter reading device (15) then receives transmissions from the first meter interface unit (12) which are governed by a first transmission rule. The meter reading device (15) determines when at least a second meter interface unit (12) is operating in an active state, and transmits to the first meter interface unit (12), a second message including a specifier for a second transmission rule.

Abstract: A meter reading system (10) for reading meter status information from meters (150) includes a meter reading device (15) for transmitting messages at a first data rate, i.e., a higher data rate, and at a second data rate, i.e., a lower data rate. Externally powered meter interface units (14) receive at least the messages transmitted at the higher data rate, and battery powered meter interface units (12) only receive the messages transmitted at the lower data rate.

Abstract: A remote meter reading system (10) includes a remotely accessible meter interface unit (12). The meter interface unit (12) is operable in an activated mode and in an inactivated mode. The meter interface unit (12) is periodically activated to monitor a communication channel to detect whether there is communication activity (410). When communication activity is detected (430), the meter interface unit (12) is operated in a message monitoring mode to monitor the communication channel (450, 460). When a message addressed to the meter interface unit (12) is detected during the monitoring period (470), the meter interface unit (12) is placed in an activated mode for an extended time period to process communication signals (485). If no communication activity is detected when periodically activated (430), or if no message addressed to meter interface is detected during the monitoring period (470), the meter interface unit (12) is placed in an inactivated mode (440).

Abstract: In order to program the output frequency of a synthesizer such as that of a two-way radio, first the reference oscillator is warped or tuned substantially to one limit of its tuning range. The "N" divisor of the synthesizer dividor is then selected to produce a loop output close to the desired loop output frequency. The reference oscillator is then tuned to provide the desired loop output frequency.

Abstract: A radio system (100) includes a plurality of addressable processors (150, 180, and 200). A communication link (230) interconnects the addressable processors (150, 180, and 200). The communication between the addressable processors is conducted via a first and a second communication protocols. The first communication protocol includes a plurality of fixed length information packets for passing parametric data to or from the addressable processors at a fixed baud rate including a packet for changing the communication protocol. The second communication protocol includes a plurality of variable length information packets for passing parametric data to or from the addressable processors at selectable speeds. Whereby the operating state of the addressable processors may be determined or altered by, respectively, communicating parametric data from or to the addressable processor at variable baud rates.

Abstract: A radio (100), powered by a battery (170), can be used in remote meter reading applications. In order to conserve battery power, the radio (100) is capable of determining that a signal is an image signal rather than a signal on the desired frequency. This is accomplished by attempting to receive a signal utilizing different local oscillator signals (high side injection and low side injection). If a signal is present, as indicated by the received signal strength with both local oscillator signals, then the radio (100) will attempt to decode data. The radio (100) does not attempt to decode data when the signal is determined to be a spurious signal. The radio (100) can then be operated in a reduced power consumption mode. This results in battery savings for radios operating in the presence of an image frequency signal.

Abstract: A remote meter reading system (10) includes a group of meter interface units in which each meter interface unit (12) is operable in an inactive state, and in which each meter interface unit (12) is periodically activated to monitor a communication channel for channel activity. The meter interface unit (12) is responsive to communication signals from a meter reading device (15). To remotely read the group of meters, the meter reading device (15) initiates communication with a target meter interface unit (12) selected from among the group of meter interface units. Next, the meter reading device (15) receives a message from the target meter interface unit (12), which contains a group identifier for the target meter interface unit (12). The meter reading device (15) then transmits a message on the communication channel which includes the group identifier received from the target meter interface unit (12).

Abstract: A remote meter reading system (10) includes a group of meter interface units in which each meter interface unit (12) operates between periods of activity and inactivity. The plurality of meter interface units (12) are assigned to groups each of the meter groups having a sleep rate assigned. Upon reading each of the meter interface units (12) the sleep rate assigned to the meter interface units (12) in each of the groups is advanced to the next group's sleep rate. This process is cycled through all of the meter groups in the system in order for all of the meter interface units to have approximately the same amount of overall battery savings.

Abstract: A remote meter reading system (10) includes a group of meter interface units in which each meter interface unit (12) operates between periods of activity and inactivity. The meter interface unit has stored first (400) and second (500) operational schedules, and a third schedule (600) which is used to determine whether to use the first (400) or second (500) schedule. The first (400) and second (500) schedules inform controller (26) when to provide a control signal to power control circuit (27) in order to stop the flow of battery energy from battery (25) to communication unit (24). Thereby, conserving valuable battery energy during those periods of time when the meter interface unit (12) is not likely to be interrogated by meter reading device (15).

Abstract: A communication system (100) is provided comprising a communication resource controller (110) wherein the likelihood of success for establishing synchronous digital communication with a communication unit (120) is substantially greater than the likelihood of success for establishing analog communication. The communication unit may establish analog communication after the communication resource controller receives a digital access code from the communication unit. The analog communication is deferred until the received signal strength from the communication resource controller is above a predetermined level which makes the establishment of analog communication substantially likely.