US 4,672,374 AGranted

System for bilateral communication of a command station with remotely located sensors and actuators

AssigneeFirecom, Inc.

InventorPaul A. Desjardins

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Abstract

A remote sensing and control system wherein a plurality of remote sensing units are connected to a central control and monitoring console by only four interconnecting wires. A clock signal is converted to a plurality of parallel address signals at the local monitoring console and also at the remote sensing units located up the building. A sync signal is employed to synchronize all of the serial-to-parallel converters in the system, and each remote unit is provided with a specific code and is identified by selectively routing one or more signals through an inverter located at each unit so that the signals trigger a logic device in the particular time slot assigned to each remote unit. The input circuitry of each remote sensing unit compares two reference signals derived from the least significant bit of the address signals with the return signal from the sensing device to sense for opens, grounds, normal conditions, and alarms. The system is adapted to operate with conventional computing means and programmable read only memories, as well as a multiplexer unit, for providing control signals to operate controlling devices upon the occurrence of predetermined signals from the sensing device. Monitoring of command functions to activation remote devices is also provided.

Claims14

Dependent claims

A remote sensing and control system, comprising:

generator means producing a clock signal;
a serial-to-parallel converter means connected to receive said clock signal and producing a first plurality of parallel address signals;
display means connected to receive said first plurality of parallel address signals;
address means remotely located from said serial-to-parallel converter means and coupled thereto in actuated relationship for producing a second plurality of parallel address signals identical to said first plurality of parallel address signals;
a plurality of sensor means each having a preselected address and having an altered electrical state upon sensing a selected parameter or upon the occurrence of a malfunction of said sensor means;
multiplexing means having inputs connected to each of said plurality of sensor means and being connected to receive said second plurality of parallel address signals, for interrogating a selected one of said plurality of sensor means upon the occurrence of the address of the selected sensor means at said multiplexing means and for producing a monitoring signal indicating the state of said sensor means;
means coupled between said sensor means and said multiplexing means for encoding sensor signals into digital words to be transmitted as said monitoring signal;
remotely located means for generating command signals for activation of remote devices, said encoding means including means for signaling the presence of said command signals;
centrally located means for actuating said command signal generating means;
and
means feeding said monitoring signal to said display means for displaying the state of said sensor means during the occurrence of the address of the selected one of said plurality of sensor means.

8 more elements

A remote sensing and control system, comprising:

a signal generator producing a serial clock signal;
a centrally located serial-to-parallel converter means connected to receive said serial clock signal for producing a first plurality of parallel address signals, each signal having a different wavelength;
a centrally located display means connected to receive said first plurality of parallel address signals for providing an information display to an operator of the system;
a plurality of remotely located environmental parameter sensing means, each having associated therewith an individual address represented by the instantaneous values of said first plurality of parallel address signals at preselected times;
at least one remotely located address means synchronized with said serial clock signals for producing a second plurality of parallel address signals identical to said first plurality of parallel address signals;
a remotely located interrogating means connected to said plurality of sensing means and connected to receive said second plurality of parallel address signals for interrogating a selected one of said plurality of sensing means upon the occurrence of the address of the corresponding selected sensing means, for producing a monitoring signal indicating a sensed environmental parameter;
means coupled between said sensing means and said interrogating means for encoding sensor signals of said sensing means into digital words to be transmitted as said monitoring signal;
remotely located means, responsive to actuation of centrally located command switch means, for generating command signals for activation of remote devices, said encoding means including means for signaling the presence of said command signals;
and
means connecting said monitoring signal to said display means for displaying the information in said monitoring signal during the occurrence of the address of the corresponding selected one of said sensing means.

7 more elements

Dependencies are inferred from the claim text.