JPH0373097A - Fire sensor - Google Patents

Abstract

PURPOSE:To perform diagnosis including future prediction with high accuracy by providing a memory circuit which stores the output of a sensing part as a diagnostic result at every execution of self-diagnosis. CONSTITUTION:The memory circuit 7 which stores the output of the sensing part 10 as the diagnostic result at every execution of the self-diagnosis is provided, and all the diagnostic results stored in the memory circuit 7 can be read out with a readout signal inputted from the outside. Therefore, the output of the sensing part 10 in the self-diagnosis is stored as the detail content of the diagnosis even when a normal diagnostic result is obtained, thereby, the history of the diagnostic result can be held. Also, the history of the diagnostic result can be read out with the readout signal inputted from the outside. In such a manner, the change of the characteristic of a fire sensor can be recognized, and the diagnosis including the future prediction with high accuracy can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a fire detector that detects smoke concentration, heat, and the like.

[Conventional technology 1] In an automatic fire alarm system, a fire detector that detects smoke, heat, etc. is connected to a fire receiver via a detector line consisting of a pair of signal lines, and the output of the fire detector is connected to a fire receiver (Ftfi). We are monitoring and monitoring the fire.

By the way, some automatic fire alarm systems of this type are designed to provide a diagnostic signal to the fire detector from the outside to cause the fire detector to self-diagnose whether there is any abnormality. As a self-diagnosis method for such fire detectors, the fire detector itself creates a simulated state similar to that at the time of a fire, and checks whether the output of the sensing section that detects smoke density, heat, etc. at this time is normal. The system is designed to determine the current C# and perform the own C# disconnection.

[Problems to be Solved by the Invention] However, in the conventional fire detector of this type, the diagnosis signal is inputted and only judges whether it is normal or not, but the diagnosis result and its detailed contents are not retained. It had not been done. For this reason, it is only possible to perform so-called post-processing diagnosis, such as taking measures such as replacing the fire detector when an abnormality occurs, and more accurate diagnosis, such as predicting whether or not an abnormality will occur in the future, can only be performed. There was a problem that could not be diagnosed.

The present invention has been made in view of the above-mentioned points, and its purpose is to provide a fire detector that can perform highly accurate diagnosis including future prediction.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a memory circuit that stores the output of the sensing unit as a diagnosis result every time a self-diagnosis is performed, and a All diagnostic results stored in the storage circuit can be read out.

Note that the average value of the output of the sensing section during the input period of the diagnostic signal may be stored in the storage circuit as the diagnostic result. Further, a write signal may be inputted from the outside separately from the above diagnostic signal, and the diagnostic result may be stored in the storage circuit using the second write signal.

[Function] As described above, the present invention includes a memory circuit that stores the output of the sensing unit as a diagnosis result every time a self-diagnosis is performed, so that even when the diagnosis result is normal, the detailed contents can be stored as zero. The output of the sensing section at the time of diagnosis is memorized so that a history of the diagnosis results can be kept, and the history of the diagnosis results can be read out by a readout signal inputted from the outside. , it is possible to detect changes in the characteristics of fire detectors and perform highly accurate diagnosis, including future predictions.

[Example] FIG. 1 shows an example of the present invention. In this embodiment, the present invention is applied to an automatic fire alarm system equipped with a photoelectric smoke detector.

This rechargeable smoke detector includes a smoke introduction chamber (not shown);
The sensor detects the concentration of smoke flowing into the smoke introduction chamber, and as shown in FIG.
A light emitting circuit 1 that emits light; a light receiving circuit 2 that receives light scattered by smoke particles of the light emitted by the light emitting circuit 1;
An amplifier circuit 3 that amplifies the output of the light receiving circuit 2, and an A/D converter that converts the analog value that is the amplified output into a digital value.
It is vjr& with the D conversion circuit 4. This smoke detector includes a signal processing circuit 5 that has a function of performing self-diagnosis when a diagnostic signal is input from the outside, and a memory that stores the output of the sensing unit 10 as a diagnosis result every time a self-diagnosis is performed. It includes a circuit 7 and a transmitting circuit 6 that sends sensing data and the like to the fire receiver.

Here, the memory circuit 7 is a non-volatile memory (E
'FROM).

In this smoke detector, a light emitting circuit 1 is driven to emit light at a constant cycle by a signal processing circuit 5, the output of the light receiving circuit 2 during this light emitting period is amplified by an amplifier circuit 3, and this amplified output is converted into a digital signal by an A/D converter circuit 4. The signal is converted into a value and input to the signal processing circuit 5. In the signal processing circuit 5, this A/D conversion output signal circuit 6 sends the signal to the fire receiver via the sensor line. Note that the smoke detector may send sensing data to the fire receiver as a digital value, but in other cases, the digital value may be converted to an analog value and sent.

Now, when no smoke is generated, the light from the light emitting circuit 1 is not received by the light receiving circuit 2, and the output of the sensing section 10 at this time is small. When a fire occurs, the smoke flowing into the smoke introduction chamber causes the light emitting circuit 1 to
The light is scattered and the output of the sensing unit 10 increases, and the fire receiver that receives the sensing data at this time determines that there is a fire.

The operation when a diagnostic signal is input will be described below. When the diagnostic signal shown in FIG. 2(c) is input, the signal processing circuit 5 controls the light emitting circuit 1 to emit the light emitting pulse shown in FIG. 2(d) instead of the normal operation time shown in FIG. 2(b). Emit the diagnostic light pulse shown in . As shown in Figure 2(e), the amount of light emitted from this diagnostic light pulse is greater than the amount of light emitted from the normal light pulse (the light intensity is strong), and in this case, stray light due to reflection from the optical system, etc. As the amount of light received by the light receiving circuit 2 increases, the output of the sensing section 10 increases as shown in FIG. That is, at the time of self-diagnosis, a pseudo fire condition similar to that of high smoke concentration is created by increasing the light emitting output of the light emitting circuit 1.

At this time, the signal processing circuit 5 self-diagnoses whether there is any abnormality by comparing the output of the sensing 910 with a reference value for determining whether or not this output is normal.

If there is an abnormality at this time, an abnormality signal is sent to the fire receiver via the transmission circuit 6 to notify the fire receiver of the abnormality. In addition, if it is normal, it sends a normal signal to the fire receiver or notifies it of normality without sending any signal. Note that the signal processing circuit 5
Each time a self-diagnosis is performed, the output of the sensing section 10 is sequentially stored in the storage circuit 7, and a history of the diagnosis results is kept. Here, as a method of storing the output of the sensing section 10, the output of the sensing section 10 for each light emitting cycle of the light emitting circuit 1 may be stored as is, or the output of the sensing section 10 during the input period of the diagnostic signal may be stored as is. It may be possible to store the average value of the output.1゜In the above smoke detector, the diagnostic results stored in the memory circuit 7 can be read out.In this case, a readout signal is input from the outside. Read the data.

At this time, the signal processing circuit 5 stops its normal operation, reads data from the memory circuit 7 in order from the oldest among the past diagnosis results, and sends it to the fire receiver via the transmitting circuit 6. Note that a clock signal for reading diagnostic data is simultaneously input from the outside, and the diagnostic data is sequentially sent to the fire receiver in synchronization with this clock signal. Then, when there is no more read signal or no more diagnostic data to read, the signal processing circuit 5 returns the operation of the smoke detector to normal operation. In this way, past diagnostic results can be stored and read even when they are normal, so for example, deterioration of the light emitting element, dirt on the optical system, changes in the characteristics of the light receiving element, changes in circuit components, etc. It is possible to grasp the state of change in the output of the sensing unit 10 due to changes in characteristics, etc., and therefore it is possible to comprehensively perform highly accurate diagnosis, which is also useful for investigating the cause when false alarms or missing alarms occur. It is also possible to predict the future, such as whether there is a high possibility that a smoke detector will become abnormal.

By the way, in the above explanation, the diagnosis result is stored in the storage circuit 7 every time a diagnosis signal is input, but there is also a mode in which a write signal is input from the outside separately from this diagnosis signal, and a self-diagnosis is simply carried out. It is also possible to provide a mode in which a self-diagnosis is performed and the diagnosis result is stored.In this case, if the timing of inputting the write signal is set to a constant period, an easy-to-understand history can be left.

In addition, in the above explanation, we have explained the case where the fire detector is connected to the fire receiver through an individual detector line, but of course, if multiple fire detectors are connected to the fire receiver via the detector line, It goes without saying that the present invention can also be applied to fire detectors in automatic fire alarm systems, where data such as smoke concentration and heat is sent to the fire receiver by transmitting signals using time-division multiplexing between the receiver and the fire receiver. In this case, a diagnostic signal, readout signal, etc. are sent from the fire receiver. Further, the present invention can be similarly applied to a heat sensor.

[Effects of the Invention] As described above, the present invention includes a memory circuit that stores the output of the sensing unit as a diagnosis result every time a self-diagnosis is performed, so even if the diagnosis result is normal, the detailed contents can be stored. As a result, the output of the sensing unit during self-diagnosis can be stored and a history of diagnosis results can be left, and this history of diagnosis results can be read out using a readout signal input from the outside, so the characteristics of the fire detector can be This has the advantage of being able to detect changes in the amount of energy and perform highly accurate diagnosis, including future predictions.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a circuit configuration of an embodiment of the present invention, and FIGS. 2 and 3 are respectively explanatory diagrams of the same operation. 5 is a signal processing circuit, 7 is a storage circuit, and 10 is a sensing section.

Claims (3)

[Claims] (1) Fire detection that performs self-diagnosis by creating a pseudo state similar to when a fire occurs using diagnostic signals input from the outside, and determining whether the output of the sensing unit that detects smoke concentration, heat, etc. is normal. The fire detector is equipped with a memory circuit that stores the output of the sensing section as a diagnosis result each time the self-diagnosis is performed, and the diagnosis result stored in the memory circuit can be freely read out by a readout signal input from the outside. (2) The fire detector according to claim 1, wherein the average value of the output of the sensing section during the input period of the diagnostic signal is stored in the memory circuit as the diagnostic result. (3) A fire detector according to claim 1, wherein a write signal is externally inputted separately from the diagnostic signal, and the diagnostic result is stored in the storage circuit using the write signal.