초록 ▼

A remote automatic utility reading system includes a reading control center for transmitting commands to and receiving measurement data from remote terminal units via a command responsive control unit. The control unit is characterized by a computer having a stored program of subroutines, one of whi

A remote automatic utility reading system includes a reading control center for transmitting commands to and receiving measurement data from remote terminal units via a command responsive control unit. The control unit is characterized by a computer having a stored program of subroutines, one of which is an interrupt subroutine. The interrupt subroutine is periodically entered as commands are received by the control unit from the reading control center and directs entry into other ones of the subroutines for execution thereof to effect the simultaneous interlacing of the commands and measurement data being transferred between the reading control center and the remote terminal units.

대표청구항 ▼

A remote automatic utility reading system having command and message interlacing for reading the measurement of a commodity over a power line comprising: (a) a plurality of addressable terminal units connected to the power line and being substantially instantaneously responsive to commands received

A remote automatic utility reading system having command and message interlacing for reading the measurement of a commodity over a power line comprising: (a) a plurality of addressable terminal units connected to the power line and being substantially instantaneously responsive to commands received thereby to transmit messages representative of measurement data onto the power line; (b) a reading control center for transmitting commands at prescribed intervals while simultaneously receiving messages, said commands being transmitted as characters, with idle characters interspaced during the intervals therebetween, each of said commands having an address field, a function code field and an action field; and (c) a control unit interconnecting said reading control center with said terminal units, via said power line, for simultaneously transferring commands and messages between said reading control center and said terminal units, said control unit comprising, (1) first and second storage means for storing first and second commands respectively received from said reading control center, (2) decode means responsive to the address and function code fields of commands received from said reading control center to effect the transfer of those received commands to said terminal units which contain an address and function code recognized by said decode means, and for further enabling said control unit to transfer messages from those terminal units to said reading control center which recognize the function code and an address in the action field of commands received by the terminal units, (3) communication means connected to said reading control center for transferring messages to said reading control center and for transferring sequentially received first and second commands from said reading control center into said first and second storage means respectively, said communication means generating a system synchronizing clock signal each time a character is received from said reading control center to effect the synchronous storage of commands in said first and second storage means, the transmission of commands from said control unit to said terminal units and the transfer of messages from the terminal units to said reading control center, via said control unit, (4) first and second counter means, each associated with a respective one of said first and second storage means and each responsive to the clock signal for counting the characters of commands received by said communication means, and (5) control means responsive to counts in said first and second counter means to effect the generation of control signals at prescribed counts of said first and second counter means to selectively identify said first and second storage means and control the time of storage of the first and second commands in the selectively identified first and second storage means, and control the time of transmission of the first and second commands from said first and second storage means to the terminal units and further control the time of reception and the transfer of messages from the terminal units to the reading control center, via said control unit, whereby, while the first command from said first storage means is being transmitted, the second command is being stored in said second storage means and the messages from the terminal units responding to the first transmitted command are being received by said control unit and transferred therefrom to said reading control center while the second command from said second storage means is being transmitted to the terminal units and a subsequent command from said reading control center is being stored in said first storage means.