Method for diagnosing deterioration tendency of transmission waveform in fire receiver and fire sensing system

Abstract

To facilitate specifying a cause when a failure occurs in digital transmission.SOLUTION: A fire receiver detects a failure of a pulse signal due to digital transmission with a fire sensor, and records a time when the failure has occurred and pulse waveform information of the vicinity of the time when the failure has occurred when the failure is detected.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for diagnosing the deterioration tendency of a transmission waveform in a fire receiver and a fire detection system that perform digital transmission. [Background technology]

[0002] An R-type receiver, a type of fire receiver, performs digital transmission between detectors and repeaters. The R-type receiver transmits downstream signals to analog fire detectors and repeaters as voltage pulses that change between low voltage (e.g., 18 volts) and high voltage (e.g., 30 volts). Similarly, upstream signals from analog detectors and repeaters are transmitted as voltage pulses. The fire receiver in Patent Document 1 also functions as a gas leak alarm. Not only the R-type receiver shown in Patent Document 1, but also improved P-type receivers perform digital transmission between fire receivers and detectors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-27384 Summary of the Invention [Problem to be solved by the invention]

[0004] In fire detectors that use digital transmission between detectors and other devices, such as R-type receivers and improved P-type receivers, digital transmission problems between detectors and repeaters can corrupt transmitted information, resulting in no response and delayed issuance of false fire alarms and fire alarms. Digital transmission problems can arise for a variety of reasons. However, problems are not always reproducible. For example, if the insulation of the digital transmission line connected to the fire detector deteriorates and peels, resulting in poor insulation, the line becomes unstable against noise factors such as vibration, induced current, and rain, making the transmission waveform susceptible to noise. Furthermore, in factories and other locations where digital transmission lines connected to fire detectors are located near electrical equipment wiring, noise can also occur in the transmission waveform if the electrical equipment is powered on and the generated electromagnetic waves affect the digital transmission line, causing noise.

[0005] Even if a malfunction occurs in digital transmission, the system will go into a no-response state and issue an alarm as a transmission abnormality, so it does not necessarily mean that there will be an immediate delay in issuing non-fire alarms or fire alarms. However, if the malfunction is left unattended, it can lead to undesirable conditions such as the test function not working properly, so it is advisable to identify the cause and take measures.

[0006] An object of the present invention is to make it possible to easily identify the cause of a problem that occurs in digital transmission. [Means for solving the problem]

[0007] In one embodiment of the present invention, a fire receiver detects malfunctions in pulse signals transmitted digitally between the fire detector and the receiver, and when such a malfunction is detected, records the time when the malfunction occurred and pulse waveform information around the time when the malfunction occurred. [Effects of the Invention]

[0008] According to the present invention, when a problem occurs in digital transmission, it becomes easy to identify the cause, and as a result, it becomes easy to take measures against the problem in digital transmission. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing the configuration of an R-type fire detection system according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of a fire control receiver according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing an example of a digital waveform detected by the fire receiver in the first embodiment. [Figure 4] 10 is a diagram showing a recording period of pulse waveform information when a waveform abnormality occurs in Example 1. FIG. [Figure 5] FIG. 10 is a diagram showing an example of a digital waveform detected by a fire alarm receiver in a modified example. [Figure 6] FIG. 10 is a diagram showing an example of a digital waveform detected by the fire receiver in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0010] Figure 1 shows the configuration of an R-type fire detection system in Example 1. A digital transmission line 2 is connected to an R-type fire receiver 1, and a plurality of analog sensors 3 and repeaters 4 are connected to the digital transmission line 2. Digital transmission is performed between the fire receiver 1 and the analog sensors 3 and repeaters 4, which are fire sensors, by sending and receiving digital signals via the digital transmission line 2. The fire receiver 1 has a display 13 and an audio alarm unit 17 on the front.

[0011] 2 shows the configuration of the fire receiver 1 in Example 1. The fire receiver 1 includes a control unit 11, a memory 12, a display 13, an operation input unit 14, a digital input / output unit 15, a voltage measurement unit 16, a voice alarm unit 17, a USB terminal 18, and a digital terminal 19. The control unit 11, the memory 12, the display 13, the operation input unit 14, the digital input / output unit 15, the voltage measurement unit 16, the voice alarm unit 17, and the USB terminal 18 are connected by a bus. The digital input / output unit 15 and the voltage measurement unit 16 are connected to the digital terminal 19. A digital transmission line 2 is connected to the digital terminal 19.

[0012] In the digital transmission of the first embodiment, values ​​of "0" and "1" are transmitted and received using a voltage pulse signal. The voltage of the digital terminal 19 is measured by the voltage measurement unit 16. FIG. 3 shows an enlarged view of the pulse waveform P measured by the voltage measurement unit 16. The pulse waveform P performs digital transmission using a pulse signal, with a high potential Hi being "1" and a low potential Lo being "0." On the receiving side, a voltage higher than the potential threshold Dth is recognized as "1," and a voltage lower than the potential threshold Dth is recognized as "0." The pulse waveform P in FIG. 3(a) transmits a digital value of "101." Noise and the like are superimposed on the pulse waveform P, and the potential fluctuates even at high potential Hi and low potential Lo, as shown in FIG. 3(a).

[0013] In the first embodiment, when the voltage of the pulse waveform P falls outside a predetermined voltage range between the abnormally high potential threshold AHth and the abnormally low potential threshold ALth, it is recognized as a malfunction A. In Fig. 3(b), when the pulse waveform P falls, the voltage becomes lower than the abnormally low potential threshold ALth, causing malfunction A.

[0014] In the case of the pulse waveform P shown in Figure 3(b), the transmitted values ​​of "0" and "1" are not destroyed, but large pulse noise such as that shown in Figure 3(b) may destroy the transmitted values ​​of "0" and "1", which is detected as malfunction A and causes the fire control device 1 to issue a transmission abnormality alarm. The transmission abnormality alarm is displayed on the display 13 and is announced by emitting an alarm sound from the audio alarm unit 17. If the transmitted values ​​of "0" and "1" are destroyed, the monitoring and test functions of the fire control device 1 will not be able to operate normally.

[0015] When a fault A occurs, pulse waveform information around the time when the fault A occurred and the time when the fault A occurred are recorded in memory 12. In the first embodiment, the pulse waveform information is recorded by measuring and recording voltage values ​​at multiple measurement timings for one pulse width PW, and a detailed shape like the pulse waveform P shown in FIG. 3(b) is recorded. However, the pulse waveform information may be measured and recorded as voltage values ​​at four or more measurement timings for one pulse width PW. The measurement timings are preferably at regular time intervals. For example, the voltage values ​​may be measured at four measurement timings for one pulse width PW, like the measurement timings of the thin vertical lines shown in FIG. 3(b).

[0016] FIG. 4 shows the recording period for pulse waveform information when a waveform abnormality occurs in Example 1. In the fire control signal receiver 1, voltage values ​​measured by the voltage measurement unit 16 are stored and older stored voltage values ​​are erased, thereby storing voltage values ​​over a period T in the past. When a malfunction A occurs, the voltage values ​​over a period T in the past from the time when malfunction A occurred are retained in the memory 12, and are stored over a period T after malfunction A. As a result, as shown in FIG. 4, voltage values ​​measured by the voltage measurement unit 16 over a period 2T, centered around the time when malfunction A occurred, are recorded in the memory 12. Information about the time when malfunction A occurred is also added to the voltage record over the period 2T.

[0017] The occurrence of malfunction A is displayed on the display 13. The operator operates the operation input unit 14 of the fire control device 1 in which malfunction A occurred, and the pulse waveform information recorded in the memory 12 is displayed on the display 13 for confirmation. The cause can then be inferred from the shape of the pulse waveform P and the time when malfunction A occurred, and appropriate countermeasures can be taken. For example, if it is determined that it is raining at the time when malfunction A occurred, it can be inferred that noise is being generated due to deterioration of the coating of the digital transmission line 2 and wetting, and appropriate countermeasures can be taken. Also, if malfunction A occurs at the same time every day due to a pulse waveform P with similar noise superimposed on it, the event occurring at that time can be identified and appropriate countermeasures can be taken. If the cause is inferred to be noise generated by a large current when the power is turned on for electrical equipment, measures such as shielding the digital transmission line 2 near the electrical equipment wiring can be taken, preventing future delays in issuing non-fire alarms and fire alarms.

[0018] <Modification> In the first embodiment, the voltage values ​​measured by the voltage measurement unit 16 are recorded in the memory 12 over a period of 2T, centered around the time when the problem A occurred. This results in a large amount of data, requiring a large storage capacity for the memory 12. In the modified example, the slope of the pulse waveform P is recorded over a period of 2T as pulse waveform information around the time when the problem A occurred, thereby reducing the amount of data stored in the memory 12. The pulse waveform information in the modified example is information relating to the slope of the pulse waveform P.

[0019] In the modified example, when malfunction A occurs, pulse waveform information around the time when malfunction A occurred and the time when malfunction A occurred are recorded in memory 12. Detection of malfunction A in the modified example is performed in the same manner as in Example 1. The configuration of the modified example is the same as in Example 1, and the configuration of the R-type fire detection system in the modified example is that shown in Fig. 1, and the configuration of the fire receiver 1 is that shown in Fig. 2.

[0020] FIG. 5 shows an example of a pulse waveform P measured by the voltage measurement unit 16 of the fire control signal receiver 1 in a modified example. The pulse waveform P inverts at a predetermined interval. In this modified example, the potential of the pulse waveform P is calculated as a line from when it crosses the predetermined high potential value Hth near the timing of the inversion until when it crosses the predetermined low potential value Lth, and the slope of the line is calculated. This slope indicates the rate of change of the voltage at the timing of the inversion of the pulse waveform P. The slope is also calculated as a line from when it crosses the predetermined low potential value Lth until it crosses the predetermined high potential value Hth. In FIG. 5, the slope of the line connecting (t1, Hth) and (t2, Lth) and the slope of the line connecting (t3, Lth) and (t4, Hth) are calculated and stored in memory 12. As shown in FIG. 4, the slopes are recorded over a period of 2T, centered around the time when malfunction A occurred. This reduces the amount of data stored in memory 12.

[0021] In the modified example, the occurrence of malfunction A is also displayed on display 13. The operator operates operation input unit 14 of the fire control panel 1 in which malfunction A has occurred, and displays and confirms the pulse waveform information indicating the slope recorded in memory 12 and the time when malfunction A occurred on display 13. Then, the operator can infer the cause from the change in slope and the time when malfunction A occurred, and take measures. [Example]

[0022] In Example 1, a malfunction A is determined when the voltage of the pulse waveform P falls outside a predetermined voltage range. In Example 2, a malfunction A is determined when the voltage of the pulse waveform P is not maintained for a predetermined time. The configuration of Example 2 is the same as Example 1, and the configuration of the R-type fire detection system in Example 2 is shown in FIG. 1, and the configuration of the fire receiver 1 is shown in FIG. 2. Also in Example 2, when malfunction A occurs, pulse waveform information for a period 2T around the time when malfunction A occurred and the time when malfunction A occurred are recorded in memory 12 as shown in FIG. 4.

[0023] 6 shows an example of a digital waveform detected by the voltage measurement unit 16 of the fire control signal receiver 1 in Example 2. The pulse waveform P in FIG. 6(a) is an example of a pulse waveform when noise is small. The period of low potential Lo is a potential lower than the potential threshold Dth, and the low potential period Da is sufficiently secured and is approximately the same as the inversion period (one pulse width PW) of the pulse waveform P. The digitally transmitted pulse signal does not have defect A.

[0024] However, when the noise superimposed on the pulse waveform P becomes large, the result is as shown in Figure 6(b). In the pulse waveform P of Figure 6(b), the low potential period Db is shorter than the inversion period and the low potential period Da, and is not maintained for the specified time. Therefore, the pulse waveform P of Figure 6(b) results in defect A. The end of the low potential period Db, when it is determined that the low potential period Db will not be maintained for the specified time, is determined to be the time when defect A occurred, and the voltage values ​​measured in the period T before and after that time are recorded in memory 12.

[0025] In the pulse waveform P in Figure 6(b), the transmitted values ​​of "0" and "1" may be corrupted, which will be detected as malfunction A and the fire control receiver 1 will issue a transmission abnormality alarm. The transmission abnormality alarm is displayed on the display 13 and is announced by emitting an alarm sound from the audio alarm unit 17. If the transmitted values ​​of "0" and "1" are corrupted, the monitoring and test functions of the fire control receiver 1 will no longer be able to operate normally.

[0026] In the second embodiment as well, the occurrence of malfunction A is displayed on the display 13. The operator operates the operation input unit 14 of the fire control panel 1 in which malfunction A has occurred, and displays and confirms the pulse waveform information based on the pulse waveform P of the voltage value recorded in the memory 12 and the time when malfunction A occurred on the display 13. Then, the operator can infer the cause from the change in the pulse waveform P and the time when malfunction A occurred, and take measures.

[0027] In Examples 1 and 2, digital transmission using voltage has been described. However, digital transmission using current may also be applied. In this case, the pulse waveform P of the current and pulse waveform information of the current value are used. Furthermore, in the case of digital transmission using current values, the pulse waveform information to be recorded may be recorded as a voltage value, and in the case of digital transmission using voltage values, the pulse waveform information to be recorded may be recorded as a current value. Furthermore, in Examples 1 and 2, the worker inferred the cause of defect A. However, the AI ​​may be trained using the cause as well as the time of occurrence of defect A and pulse waveform information, and the trained AI may then be input with the time of occurrence and pulse waveform information to infer the cause.

[0028] In Examples 1 and 2, the pulse waveform information indicating the slope recorded in memory 12 and the time when problem A occurred are displayed on display 13. However, this information may be retrieved from USB terminal 18 shown in Fig. 2 and input into another computer, where it may be displayed or the cause may be estimated using AI. In this case, the occurrence of problem A may be displayed on display 13, but if this information is retrieved during regular inspection, it does not need to be displayed on display 13.

[0029] In addition, as a method for diagnosing the deterioration tendency of the transmission waveform in a fire detection system, the pulse waveform, which is the transmission waveform transmitted by digital transmission between the fire receiver and the fire detector, may be recorded, and the recorded pulse waveform may be diagnosed by diagnosing the deterioration tendency using an eye pattern.

[0030] In Examples 1 and 2, when a malfunction is detected in the fire receiver 1, the time when the malfunction occurred and pulse waveform information around the time when the malfunction occurred are recorded. However, in the above-described deterioration tendency diagnosis method, the fire receiver is equipped with a large-capacity memory and records pulse waveform information of pulse signals digitally transmitted between the fire detector and the receiver over a predetermined period of time, not just when a malfunction occurs. The recorded pulse waveform information is analyzed by the fire receiver or another computer system to determine the malfunction status. This record can be used to capture the transition of the transmission waveform over a long period of time, thereby determining the deterioration tendency of the transmission characteristics. Then, by using an "eye pattern (eye diagram)," the transition of the transmission waveform can be visually confirmed and the deterioration tendency can be determined. The deterioration tendency of the transmission characteristics can also be determined using methods other than the eye pattern.

[0031] Furthermore, the specific configuration is not limited to the embodiments, and the present invention includes design changes within the scope of the gist of the present invention. Furthermore, the above-mentioned examples and modifications can be combined by utilizing each other's technology as long as there are no particular contradictions or problems in the purpose, configuration, etc. [Explanation of symbols]

[0032] P: Pulse waveform, Dth: Potential threshold, Hi: High potential, Lo: Low potential, AHth: Abnormally high potential threshold, ALth: Abnormally low potential threshold, A: Malfunction, PW: 1 pulse width, T: Period, Hth: High potential specified value, Lth: Low potential specified value, Da: Low potential period, Db: Low potential period, 1 Fire receiver, 11 Control unit, 12 Memory, 13 Display, 14 Operation input unit, 15 Digital input / output unit, 16 Voltage measurement unit, 17 Audio alarm unit, 18 USB terminal, 19 Digital terminal, 2 Digital transmission line, 3 Analog sensor, 4 Repeater

Claims

1. Detects malfunctions in pulse signals transmitted digitally between the fire detector and the system. When the malfunction is detected, the time when the malfunction occurred and pulse waveform information around the time when the malfunction occurred are recorded. A fire receiver characterized by:

2. The pulse waveform information is four or more voltage or current values ​​per pulse width.

2. The fire control device according to claim 1, wherein the fire control device is a

3. The pulse waveform information is information about the slope of the pulse waveform.

2. The fire control device according to claim 1, wherein the fire control device is a

4. If the voltage of the pulse waveform falls outside a predetermined voltage range, it is determined that the malfunction has occurred.

4. A fire control panel according to claim 1, wherein the fire control panel is a control panel for controlling a fire.

5. If the voltage of the pulse waveform is not maintained for a predetermined time, it is determined that the malfunction has occurred.

4. A fire control panel according to claim 1, wherein the fire control panel is a control panel for controlling a fire.

6. The fire receiver records the pulse waveform, which is the waveform transmitted by digital transmission between the fire detector and the receiver. The recorded pulse waveform is diagnosed by diagnosing the deterioration tendency using the eye pattern. A method for diagnosing deterioration tendency of a transmission waveform in a fire detection system, comprising:

Images