Disaster prevention monitoring apparatus
First Claim
1. A disaster prevention system and monitor comprising:
- a central station for transmitting command signals along signal lines;
at least one repeater station connected to said signal lines for receiving said command signals and for transmitting status information signals onto said signal lines;
control loads, control lines connected said control loads at said least one repeater station, and power lines adapted for supplying power to said control loads when connected to said control lines, said control lines normally being disconnected from said power lines;
means at said at least one repeater station, responsive to a command signal including an address field designating said at least one repeater station and a command field designating that power is to be applied to said control loads, for connecting said control lines to said power lines;
monitor means at said at least one repeater station for monitoring, when actuated, the state of said power lines and control lines when said power lines are not connected to said control lines; and
means at said at least one repeater station, responsive to a command signal including an address field designating said at least one repeater station and a command field designating that said monitoring means should be activated, for actuating said monitoring means.
1 Assignment
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Accused Products
Abstract
A disaster prevention monitor is disclosed in which the power consumption during a line monitoring process is reduced, and a disconnection or a short circuit of control lines can be detected by using a single switching means. A central station has a monitor command transmitter for transmitting a monitor command signal to initiate monitoring of power and control lines. A terminal or repeater station has circuitry for controlling the connection of control lines between a line monitor and power lines. During normal conditions, the control lines are not connected to the power lines, but become so connected only in response to a command from the central station. A line monitoring command causes generation of a negative voltage which is applied to line monitoring circuitry to actuate such circuitry for monitoring the status of the power and control lines.
30 Citations
32 Claims
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1. A disaster prevention system and monitor comprising:
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a central station for transmitting command signals along signal lines; at least one repeater station connected to said signal lines for receiving said command signals and for transmitting status information signals onto said signal lines; control loads, control lines connected said control loads at said least one repeater station, and power lines adapted for supplying power to said control loads when connected to said control lines, said control lines normally being disconnected from said power lines; means at said at least one repeater station, responsive to a command signal including an address field designating said at least one repeater station and a command field designating that power is to be applied to said control loads, for connecting said control lines to said power lines; monitor means at said at least one repeater station for monitoring, when actuated, the state of said power lines and control lines when said power lines are not connected to said control lines; and means at said at least one repeater station, responsive to a command signal including an address field designating said at least one repeater station and a command field designating that said monitoring means should be activated, for actuating said monitoring means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification