Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
1999-10-26
2001-03-20
Lee, Benjamin C. (Department: 2736)
Communications: electrical
Condition responsive indicating system
Specific condition
C340S506000, C340S505000, C340S517000, C340S521000, C340S523000
Reexamination Certificate
active
06204768
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fire monitoring system and fire sensors, which are capable of judging a fire by connecting a plurality of fire sensors to a receiver via a transmission line and then transmitting detection data from the plurality of fire sensors repeatedly in the predetermined order in response to respective instructions issued from the receiver. More particularly, the present invention relates to a fire monitoring system and fire sensors, which are capable of sending plural types of detection data selectively from the fire sensor by providing a plurality of sensors in the fire sensor.
2. Description of the Related Art
Conventionally, in the fire monitoring system which monitors a plurality of fire sensors concentratively by a receiver, the so-called multi-sensor type fire sensors each of which has functions of detecting smoke and heat are connected to the receiver via a transmission line.
According to such multi-sensor type fire sensor, when a smoke sensing circuit and a heat sensing circuit are provided such fire sensor, they can be switched according to the instruction issued from the receiver to operate individually (Unexamined Japanese Patent Publication (KOKAI) Hei 7-65263 (JP-A-7-65263)).
Therefore, the fire sensor can be operated as the smoke sensor or the smoke sensor according to the situations such as an installing location. In addition, if the fire is detected in the situation that the fire sensor is switched to the smoke sensing circuit, a false alarm can be prevented beforehand by switching the fire sensor to the heat sensing circuit to check the fire.
However, according to the fire sensor in which the smoke sensing circuit and the heat sensing circuit are switched according to the instruction issued from the receiver, there has been such a problem that a circuit configuration becomes complicated since a switching circuit is provided as a hardware to switch them. In addition, there has been another problem that, since two sensing circuits are switched so as to operate one of them and terminate the other, merely one of two sensing circuits can operate not to utilize plural types of detecting functions as a feature of the fire sensor.
Further, if the smoke sensing circuit and the heat sensing circuit are switched by allocating different addresses to respective sensing circuits, both sensing functions can be utilized by switching the address for the data request instruction. However, a plurality of addresses must be allocated to one fire sensor, nevertheless the maximum number of addresses which can be allocated to the fire sensors by the receiver is limited. As a result, there has been a problem that, since the number of address becomes insufficient, the number of the fire sensors which can be connected to the receiver is reduced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a fire monitoring system and fire sensors, which are capable of monitoring a fire appropriately by utilizing plural types of sensor functions such as smoke and heat sensing functions effectively without complication of circuit configuration and lack of address.
The present invention is directed to a fire monitoring system which can detect a fire by connecting a plurality of fire sensors to a receiver via a transmission line and then transmitting detection data from the plurality of fire sensors repeatedly in predetermined order in response to instructions from the receiver.
In such fire monitoring system of the present invention, each of the fire sensors includes a plurality of sensor portions of different types, sensor processors for outputting detection data of plural types based on detection signals from the plurality of sensor portions, and a mode switching portion for switching a mode which corresponds to detection data to be sent in response to a mode switching instruction from the receiver and sending selectively the detection data which corresponds to a current switching mode in response to a data request instruction from the receiver.
Also, the receiver includes a mode switching indicating portion for switching the mode by transmitting the mode switching instruction which selects type of response data to the fire sensors, and a fire judging portion for judging the fire by receiving the response data from the fire sensors in response to transmission of the data request instruction.
In such fire monitoring system of the present invention, the plurality of sensor portions such as the heat sensor portion, the smoke sensor portion, etc., which are provided to each of the fire sensors, are not switched, but merely the mode of the fire sensors is switched to correspond to detection data which is to be sent to the receiver, in answer to the mode switching instruction issued from the receiver since such plurality of sensor portions are always detecting the smoke data and the temperature data in the normal operation state.
As a result, switching of the plurality of sensor portions by using the hardware is not needed, and the address must be set simply in one unit of the fire sensor. Therefore, reduction in the connection number of the fire sensors, due to lack of the address caused when the address must be set for every type of data, does not happen.
Therefore, each of the fire sensors according to the present invention includes, as the plurality of sensor portions, a smoke sensor portion for detecting a smoke generated by the fire to output a smoke signal, and a heat sensor portion for detecting heat radiated by the fire to output a temperature signal, and includes, as the sensor processors, a smoke sensor data processor for converting the smoke signal into smoke data responding to the receiver and then holding the smoke data, a temperature sensor data processor for converting the temperature signal into temperature data responding to the receiver and then holding the temperature data, and a multi-sensor data processor for correcting the smoke signal based on the temperature signal to convert the smoke signal into corrected smoke data responding to the receiver and then holding the corrected smoke data.
Further, the mode switching portion of each of the fire sensors has switching functions of a smoke sensor mode to send the smoke data, a temperature sensor mode to send the temperature data, and a multi-sensor mode to send the corrected smoke data, and then switches the mode into one of the smoke sensor mode, the temperature sensor mode, and the multi-sensor mode based on the mode switching instruction issued from the receiver.
The mode switching portion of each of the fire sensors sends data corresponding to a current switching mode when it receives the data request instruction which does not designate a particular mode from the receiver. This corresponds to data collection from the fire sensor using the normal polling command after the mode has been switched, so that the data which has the type fixed in the mode after switching can be collected.
The mode switching portion of each of the fire sensors sends data in a designated mode irrespective of a current switching mode when it receives the data request instruction designating a particular mode from the receiver. This corresponds to the case where data in the mode other than the current switching mode would be collected in the normal polling, so that the data in the mode designated by the command can be collected irrespective to the current switching mode.
For example, if the fire sensor has been currently switched into the multi-sensor mode, the concerned detection data can be collected by designating the smoke mode or the heat mode from the receiver as the case may be. If the fire or the fault is detected based on the data in the multi-sensor mode, for example, this function makes it possible to judge the fire or the fault more precisely by collecting the detection data in the smoke mode or the heat mode as the different mode.
The mode switching portion of each of the fire sensors initializes the multi-sensor mode when the power supply i
Ito Masayuki
Kosugi Naoki
Hochiki Corporation
Lee Benjamin C.
Previl Daniel
Sughrue Mion Zinn Macpeak & Seas, PLLC
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