Abstract: The present invention relates to an automatic meter reading transponder. The transponder is comprised of a receiver for receiving an external instruction and a transmitter for transmitting data. A CPU is connected to the receiver and the transmitter. A ROM is connected to the CPU and ROM contains a program for controlling the operation of the CPU. A real time clock is connected to the CPU for determining sequential predetermined time periods. Three input terminals are connected to the CPU for receiving data to be stored in a RAM. One of the three input terminals has pulses impressed thereon, the number of pulses being representative of electric power consumption. The one input terminal is also connected, via the CPU to a time-of-day memory.

Abstract: The invention relates to a high speed central office scanner for use with a plurality of transponding units connected by telephone lines. The scanner is comprised of N, I/O units, each comprised of a multiplexer for connecting the I/O units to M telephone lines; a microprocessor and multiplex logic which sequentially selects one of the M telephone lines; a busy detect circuit for checking the selected telephone line and providing a signal when the line is busy; a TX/RX unit connected to the selected line for transmitting an instruction code to a transponder connected thereto when the signal is absent and for receiving data from the transponder in response to the instruction code; and a storage unit. The scanner further includes a master microprocessing unit, which includes a main microprocessor for sequentially selecting one of the N, I/O units and for generating an interrogating code for transmission to each selected I/O unit.