摘要 |
A remote metering system is disclosed, comprising one or more battery-powered metering units (12) and a central data collection unit (10, 20), each including a radio transceiver. The central data collection unit (10, 20) transmits a signal including power down time information and transmit instructions, which is received by each metering unit (12). Each metering unit (12) extracts the power down time information and transmit instructions from the signal and, if appropriate, transmits data in response to the data transmit instructions, this data being collected by the central data collection unit (10, 20). The metering units (12) then interrupt the power supply to their transceivers for a period of time dependent upon the power down time information. The central data collection unit (10, 20) delays for a slightly longer period of time before transmitting a further signal via its transceiver, at which time the power supply to the transceiver of each metering unit has already been resumed. By allowing the metering units (12) to power down to a quiescent state under the control of the central data collection unit (10, 20), flexibility is ensured and power consumption minimized. |