摘要:
An ambient condition detector incorporates a common radiant energy source to carry out a first, sensing, function and a second, information transmitting function. The source can generate a beam to implement a fire sensing function. In addition, modulated radiant energy emitted from the source can be remotely sensed to determine detector status or internal parameter values. In an alternate embodiment, a source of radiant energy can be configured at an exterior periphery of the detector and information can be wirelessly transmitted therefrom using one or more analog modulation processes.
摘要:
An ambient condition detector incorporates a common radiant energy source to carry out a first, sensing, function and a second, information transmitting function. The source can generate a beam to implement a fire sensing function. In addition, modulated radiant energy emitted from the source can be remotely sensed to determine detector status or internal parameter values. In an alternate embodiment, a source of radiant energy can be configured at an exterior periphery of the detector and information can be wirelessly transmitted therefrom using one or more analog modulation processes.
摘要:
A fire alarm system utilizes outputs from different types of fire sensors, such as photoelectric smoke sensors or ionization type smoke sensors and combines those outputs by subtraction so as to establish a delay interval during which one or both of the sensor output values must exceed a predetermined threshold value to cause the system to go into an alarm condition. Prior to subtracting the outputs from one another, each of the outputs can be raised to a predetermined exponential value so as to emphasize the effects of larger sensor output values. Where the two types of fire sensors each are generating outputs indicative of a fire condition, the calculated delays will be relatively short. In instances where only one of the two sensors is generating an output indicative of a fire condition, the calculated delay will be longer, so as to inhibit false alarms.
摘要:
An anti-disaster system for receiving terminal data in response to the sequential calling of the terminals which is achieved by designating addresses from a receiver and for performing alarming or the like. Each of the terminals has an interrupt transmission section for transmitting a break signal which invalidates a terminal response signal on a timing when the terminal response signal to the receiver is transmitted when an abnormality is detected to notify generation of an interrupt. The receiver includes an interrupt detection section for detecting an interrupt of a terminal when it receives the break signal at a timing when the terminal response signal is received, and a calling control section for specifying the terminal in which abnormality data is detected, the specification being achieved by transmitting the calling signals for interrupt confirmation to the terminals when an interrupt detection output is obtained from said interrupt signal detection section to allow the terminal to transmit the terminal response signal containing an interrupt level signal which indicates the cause of generation of the interrupt and by performing sequential group calling of the terminals on the basis of the order of priority of the interrupt level signal. Consequently, when urgent data is detected at the terminal end, terminal data can be received quickly independently of the sequential calling and generation of an abnormality can be determined.
摘要:
A remote supervisory and controlling System for remotely supervising and controlling loads in time-divisional multiplex transmission of control and monitor data between a central control and terminal units each connected to the central control unit through a two-wire line. Supervision and control of the overall system can be carried out from a plurality of locations so that failure of a central or host computer will not render the overall system inoperative.
摘要:
A multi-sensor security/fire alarm system comprises a master control unit which repeatedly interrogates, e.g., by a multiplexing scheme, the respective inputs and/or operating status of a plurality of remote sensor units (e.g., intrusion and fire sensors). In response to an alarm or other off-normal condition detected by any of the remote sensors, the master control notifies an alarm-monitoring service which either responds itself to the detected condition, or notifies the local police or fire department. To prevent one alarm-monitoring service from taking over, without authorization, the alarm-monitoring accounts of another service which may have expended considerable time and expense in installing the system, the master control unit is mated with its associated sensors by a unique code. According to a preferred embodiment, each sensor comprises an EEPROM which stores a unique portion (e.g., a single digital bit) of a multibit security code which is collectively defined by the unique code portions of all the individual sensors and stored in memory of the control unit. The control unit periodically addresses the remote sensors to compare the "distributed code" with the code stored by the control unit.
摘要:
A security/fire alarm system includes a plurality of event-sensors, e.g. intrusion and smoke sensors, each being identifiable by a unique digital address defined by a multibit binary address code. A central control unit operates to repeatedly address the sensors to determine their respective alarm and/or operating status. To minimize the cycle time required to sequentially interrogate all sensors, the central control unit operates to address groups of sensors simultaneously, each of the groups consisting of a sub-plurality of all the sensors. In response to being addressed, each sensor in an addressed group of sensors transmits a different binary bit or digit of a multibit digital response code which is defined collectively by the transmitted bits. The logical state of each of such binary bits indicates the general status (i.e. normal/abnormal) of the event-sensing unit that transmitted the bit. The control unit is responsive to the multibit response code to sequentially re-address only those event-sensing units that, through their respective binary bit, have indicated an abnormal status.
摘要:
An improved method of locating an underground mine fire by comparing the pattern of measured combustion product arrival times at detector locations with a real time computer-generated array of simulated patterns. A number of electronic fire detection devices are linked thru telemetry to a control station on the surface. The mine's ventilation is modeled on a digital computer using network analysis software. The time reguired to locate a fire consists of the time required to model the mines' ventilation, generate the arrival time array, scan the array, and to match measured arrival time patterns to the simulated patterns.
摘要:
A smoke and fire detection system wherein a central controller transmits data to remote transponders on a voltage supply line by pulse code modulation (PCM) of the supply voltage, and the transponders communicate with the controller by pulse width modulated (PWM) current pulses over the voltage supply line. A transmitter in the controller supplys a nominal operating voltage to the transponders and transmits a data word comprising a plurality of data bits to the transponders over the line. The transmitter generates each data bit by switching the voltage supplied to the line from the nominal operating voltage to a first voltage corresponding to a first logical level or a second voltage corresponding to a second logical level. A decoder in each transponder derives the transmitted data word. The decoder detects each data bit by detecting the transition from the nominal voltage to the first or second voltages, and the decoder determines the logical level of each bit by measuring the transmitted voltage level immediately after detecting the transition. The transponder returns data to the controller in the form of data signals, each data signal having a duration based on the data to be returned. With such arrangement, the transponders do not require a clock or other timing circuitry to communicate with the controller. Also, the controller may vary the data rate or bit duration without interfering with the operation of the transponders.