Coded signaling and control system

• US 4,001,772 A
• Filed: 07/30/1975
• Issued: 01/04/1977
• Est. Priority Date: 07/30/1975
• Status: Expired due to Term

• Current Assignee: Truman W. Powell
• Original Assignee: Truman W. Powell
• Inventors: Powell, Truman W., Davis, Jordan R.
• Primary Examiner(s): Yusko, Donald J.
• Application Number:
  US05/600,408
• Time in Patent Office: 524 Days
• Field of Search: 340/164, 340/167, 340/171 R, 340/171 PF, 340/171 A, 340/224, 340/311, 325/64
• US Class Current: 340/7.49
• CPC Class Codes: G08B 26/007 Wireless interrogation
• CPC Class Codes: H04W 88/188 using frequency address codes

Abstract

A coded signaling and control system including one or more transmitters and one or more receivers, wherein both the transmitters and the receivers are coded or programmed to transmit a unique signal for actuating only selected ones of the receivers. Digital logic and switching circuits are used to generate a transmission sequence containing an initial reset burst followed by alternate shift and code bit signals terminating with a comparison and latching signal. All of the receivers in the system receive the initial reset signal and the alternate shift and data bit sequence; however, only the selected receiver programmed for the precise code being transmitted will generate a true comparison signal. Thereafter, all of the other receivers will be reset and the desired receiver will be sequenced to respond to an "off" or "on" latching signal for providing any desired output function, such as operating an alarm, controlling an associated piece of equipment, and the like. Using an eight bit word in the coded message, 255 discrete codes may be used such that triggering of other than the single preselected receiver is precluded. In addition, by varying the tone frequencies used in the code bit generator, many thousands of additional discrete coded combinations can be provided.

Claims

1. A selective signaling and control system comprising a transmitting circuit including a first network for generating a start and reset signal at a first frequency, a second network for generating a shift and code word comprising a plurality of alternate second and third frequency tones representing shift and code bit signals, respectively, and a third network for generating a latch control signal at a frequency differeing from said first, second and third frequencies;

and a receiving circuit including first means responsive to said start and reset signal for assuming a data receive mode, second means responsive to said alternate shift and data bit signals to store said data bit signals to sequence, means comparing said stored data bit signals with a preselected code and generating an output when the two are equal, and a network enabled by the output of the comprising means to respond to said latch control signal for activating an output device.

2. The invention as recited in claim 1 wherein said output device comprises means for audio communication having a normally quiescent state and responsive to said latch control signal for assuming an active state to enable audio communication.

3. A selective signaling and control system comprising first means for generating a start and reset signal at a first frequency;

second means for generating a preselected code signal comprising a plurality of alternating tones at second and third frequencies;

third means for generating an on/off latching signal at a frequency differing from said first, second and third frequencies; and

fourth means coupled with said first, second, and third means for sequentially controlling the same to generate a composite coded message;

wherein said second generating means comprises a pair of different frequency tone generators and shift means alternately enabling each of said tone generators;

said shift means comprising a clock network, a shift/code flip-flop having a trigger input connected to an output of said clock network for periodically changing states in response to said clock output, and gate means coupled with the output of said shift/code flip-flop and said tone generators to alternately enable the same;

said gate means comprising a first gate controlling the output of a first one of said tone generators and a second gate controlling the output of a second one of said tone generators, said first and second gates being responsive to said shift/code flip-flop; and

a decade counter coupled with said shift/code flip-flop and said second gate through a patching network for controlling said second gate in accordance with a preprogrammed code.

4. The invention as recited in claim 3 wherein said third means comprises third and fourth tone generators, and means coupled to said generators for selectively enabling one of said third and fourth tone generators, said selective enabling means comprising a latch mode flip-flop having a pair of output terminals connected to one input of a pair of latch control gates, respectively, each of said latch control gates having a second input connected to receive a respective output of said third and fourth tone generators.

5. In a selective signaling and control system, a transmitting circuit comprising

a signal output network;

first means for generating a start and reset signal at a first frequency;

second means for generating a signal at a second frequency;

third means for generating a code bit signal at a third frequency;

first, second, and third gate means connected to said first, second and third generating means, respectively, for coupling the outputs thereof to an input of said signal output network,

a programmable decade counter coupled at an output to said first and third gate means for opening and closing said first and third gate means in a preselected sequence thereby to control the presence and absence, respectively, of said first and third frequency tones at the input of said signal output network; and

clock controlled switching means coupled to said first, second and third gate means and said decade counter for alternately enabling and disabling said second gate means and said decade counter whereby the signal fed to said signal output network consists of a series of tone bursts comprising said second frequency tone alternated with a first or third frequency tone as enabled by said decade counter.

6. In a selective signaling and control system, a receiving circuit comprising

first means responsive to a start and reset signal at a first frequency for providing a sequence start signal;

second means coupled to said first means and responsive to a series of alternating tones at second and third frequencies, respectively, when said sequence start signal is provided, for storing each of said received third frequency tone signals as a separate data bit at a serial position sequentially advance by each received second frequency tone signal;

means comparing said stored data bit signals with a preselected code and generating an output when the two are equal; and

control means enabled in response to the output of said comparing means to respond to a tone signal at a fourth frequency to contol an output device.

7. The invention as recited in claim 6 wherein said second means comprises a shift register, and wherein said comparing means comprises a preset code selector and a binary comparator connected to receive and compare output signals from said shift register and said preset code selector.

8. The invention as recited in claim 6 further including input means coupling said tone signals to said first and second means, said input means comprising a phase locked loop frequency to voltage converter;

and wherein said first and second means comprise voltage comparators each having a filtering network and a pair of differential amplifiers.