JP2021064186A - Abnormality detection system - Google Patents

Abstract

To provide an abnormality detection system with a simple configuration and high reliability.SOLUTION: An abnormality detection system includes an abnormality detection device having an abnormality determination unit that determines whether or not a predetermined abnormality is detected, and an input/output unit that outputs the determination result by the abnormality determination unit as a digital signal to a signal converter and transmits/receives the digital signal to/from the signal converter. The abnormality detection system further includes: a signal converter that relays the transmission and reception of signals between the abnormality detection device and a host device; a power supply part that supplies power to the abnormality detection device; a plurality of signal transmission lines 90A and 90B for transmitting the digital signals provided so as to connect between the signal converter and the input/output unit; and a cable part 90 that supplies the power to the abnormality detection device from the power supply part. Each of the input/output unit and the signal converter transmits and receives the digital signals on the plurality of signal transmission lines 90A and 90B by using different signal transmission methods.SELECTED DRAWING: Figure 2

Description

The present invention relates to an abnormality detection system.

Anomaly detectors that detect and output fires in the monitoring area are required to have highly reliable transmission technology due to the nature of transmitting signals that notify of abnormal conditions (fire, abnormal temperature, etc.). As the above measures, measures against disconnection of the signal transmission line, a mechanism for confirming the function of the abnormality detector, and the like have been proposed (Patent Documents 1 and 2). In addition, a network has been proposed in which the transmission path is duplicated to improve reliability.

Japanese Unexamined Patent Publication No. 2019-106023 JP-A-2017-117358 Japanese Unexamined Patent Publication No. 2016-71460

On the other hand, for anomaly detectors installed in dangerous places filled with flammable gas, etc., the above mechanism cannot be applied as it is due to restrictions on explosion-proof structure and energy, and most of them are connected to the control panel on a one-to-one basis. It is a pressure-resistant explosion-proof type abnormality detection system that outputs contacts in the event of an abnormality such as a fire. Although this abnormality detection system is a highly reliable method for transmitting fire signals because it is a one-to-one connection or a simple transmission method, it is difficult to identify the location of the transmission path disconnection and there are multiple abnormality detectors. There are problems such as high cost when installing and installation only up to ZONE1.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a highly reliable abnormality detection system with a simple configuration.

In order to achieve the above object, the abnormality detection system according to the present invention is based on an abnormality determination unit that determines whether or not a predetermined abnormality has been detected based on the sensor information detected by the sensor, and the abnormality determination unit. The determination result is output as a digital signal to the signal converter, and the abnormality detector including the signal converter and the input / output unit for transmitting and receiving the digital signal relays the transmission and reception of the signal between the abnormality detector and the host device. A plurality of signals for transmitting the digital signal, which are provided so as to connect the signal converter to be performed, the power supply unit for supplying power to the abnormality detector, and the signal converter and the input / output unit. Each of the input / output unit and the signal converter includes a signal transmission line and a transmission cable unit that supplies power to the abnormality detector from the power supply unit, and each of the input / output unit and the signal converter has the plurality of signal transmission lines. Then, the digital signal is exchanged using different signal transmission methods.

According to the abnormality detection system which is one aspect of the present invention, it is possible to obtain an effect that a highly reliable abnormality detection system can be provided with a simple configuration.

It is a block diagram which shows the structure of the abnormality detection system which concerns on 1st Embodiment of this invention. It is the schematic which shows the structure of the cable part which concerns on 1st Embodiment of this invention. It is a graph which shows the change of the current in the transmission system using Manchester coded bus feeding. It is a figure for demonstrating the transmission system using the balanced differential signal transmission. It is a graph which shows the change of voltage in the transmission system using the balanced differential signal transmission. It is an image diagram when an abnormality detector is connected in a tree. It is a graph which shows the change of the voltage in the transmission system using Manchester coded bus power supply. It is a graph which shows the change of voltage in the transmission system using high frequency voltage modulation. It is a block diagram which shows the structure of the abnormality detector which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structure of the arithmetic processing part of the abnormality detector which concerns on 1st Embodiment of this invention. It is a figure which shows the data structure of the transmission signal from an abnormality detector. It is a sequence diagram which shows the exchange of a signal between a superordinate system of an abnormality detection system at a normal time, a signal converter, and an abnormality detector. It is a sequence diagram which shows the exchange of a signal between a higher level system of an abnormality detection system at the time of an abnormality, a signal converter, and an abnormality detector. (A) A graph showing a change in the current of a single fire signal, (B) a graph showing a change in the current of a single fire signal, and (C) a graph showing a change in the current of a signal obtained by superimposing two fire signals. is there. It is a sequence diagram which shows the signal exchange between the upper system of an abnormality detection system, a signal converter and an abnormality detector when a fire signal is output at the same time. It is an image diagram at the time of disconnection or short circuit of a cable part. It is a block diagram which shows the structure of the abnormality detection system which concerns on 2nd Embodiment of this invention. It is an image diagram at the time of disconnection or short circuit of a cable part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Outline of Embodiment of the present invention>
An embodiment of the present invention relates to a network configuration of an abnormality detection system that detects a fire or an abnormal temperature at a dangerous place (combustible gas vapor place, flammable dust place) and outputs the information to a higher-level system. ..

In this network configuration, the properties listed below are particularly required, and the network configuration and the data transfer method that satisfy these properties and are optimal for the abnormality detection system are characterized.

(1) Redundant fire signals or abnormal temperature signals are reliably transmitted.
(2) It can be installed in a dangerous place (ZONE0) where the technical requirements are the strictest.
(3) High safety level (corresponding to disconnection and short circuit of transmission path).
(4) Construction cost and maintenance cost are low.
(5) The abnormality detector normally consumes only the current required for fire monitoring and outputs a status signal at regular intervals. When an abnormality is detected, a signal is output to the host system at that stage.

Specifically, by transmitting the fire signal by two different transmission methods, a network configuration having high redundancy is realized. Further, by accommodating the transmission lines for the above two types of transmission methods in one transmission cable, the cost of network construction and equipment can be reduced.

In addition, by duplicating the network, the fire monitoring environment can be continued even if the cable is broken or short-circuited. In addition, the current consumption during communication is suppressed, and the number of anomaly detectors that can be installed in dangerous places is increased. Furthermore, by using polling that is simple and has high transmission reliability, the loss of the fire signal from the abnormality detector is prevented, and the data transmission is made highly reliable.

[First Embodiment]
<System configuration>
Hereinafter, the abnormality detection system according to the first embodiment of the present invention will be described.

As shown in FIG. 1, the abnormality detection system 100 according to the first embodiment of the present invention includes a plurality of abnormality detectors 10, a barrier 70, a signal converter 72, a power supply unit 74, and a host system 80. And have.

The signal converter 72 and the plurality of abnormality detectors 10 are connected by a cable unit 90.

The host system 80 includes one or more of a host computer 82, a DCS / PLC 84, a control panel 86, and a fire receiver 88. The host system 80 and the signal converter 72 are connected to each other via the network 92. The abnormality detector 10 is installed in a dangerous place, and the barrier 70, the signal converter 72, the power supply unit 74, and the host system 80 are installed in a non-dangerous place.

The signal converter 72 relays the transmission and reception of digital signals between the abnormality detector 10 and the host system 80. The power supply unit 74 supplies electric power to each abnormality detector 10 via the cable unit 90.

A plurality of abnormality detectors 10 installed at dangerous locations are connected to the cable portion 90 via a T-branch connector 90C, and the host system 80 is connected via a barrier 70 and a signal converter 72 provided at non-dangerous locations. And half-duplex communication. Here, the barrier 70 plays a role of limiting the energy supplied to the abnormality detector 10 and suppressing the overvoltage and overcurrent generated at the time of disconnection or short circuit to a level at which sparks leading to ignition do not occur. Further, the signal converter 72 plays a role of converting a transmission signal between the abnormality detector 10 and the host system 80, and monitors the network state (bus line disconnection, short circuit monitoring, etc.). As the network 92, Ethernet (R), RS-485, etc. can be selected according to the communication specifications of the host system, and the network 92 has expandability to the control panel 86 and the fire receiver 88.

Although FIG. 1 shows a bus connection centered on one cable portion 90, a tree structure is also possible.

<Signal transmission (abnormality detector → signal converter)>
As shown in FIG. 2, the cable unit 90 is a signal transmission line 90A for transmitting a digital signal, which is provided so as to connect between the signal converter 72 and the input / output unit described later of the abnormality detector 10. , And a signal transmission line 90B for transmitting a digital signal and supplying power to the abnormality detector 10 from the power supply unit 74.

The abnormality detector 10 transmits signals (unique address / fire signal / abnormal temperature signal / state information, etc.) to the signal converter 72 via signal transmission lines 90A and 90B by two different transmission methods. .. Here, as the first transmission method on the signal transmission line 90A, Manchester-coded Bus Powered (MBP), in which a Manchester-encoded transmission signal is placed on the power supply line, is used. In MBP, the basic current consumption is supplied to each abnormality detector 10, and the communication current (for example, 10 [mA]) is supplied to the abnormality detector 10 that transmits signals, and the current in the abnormality detector 10 is supplied. A current signal is transmitted by modulation (for example, ± 9 [mA]) (see FIG. 3). The second transmission method on the signal transmission line 90B is balanced differential signal transmission of voltage amplitude, and the two paired signal lines constituting the signal transmission line 90A have opposite phases. A voltage signal is transmitted (see FIGS. 4 and 5). Both transmission methods are established technologies as transmission methods to dangerous places, and are highly reliable transmission methods.

In the abnormality detection system 100 according to the present embodiment, a network having high redundancy is realized by transmitting signals using both different transmission methods. Here, the features of each transmission method are shown in Table 1.

Further, both of the above data transmissions are carried out at a low transmission speed of about 30 kbps at the maximum. For example, the transmission speed of the digital signal is 10 kbps to 30 kbps. At the above speeds, it is not necessary to consider impedance matching except for long-distance transmission (several tens of kilometers or more) (no need to consider signal reflection due to branching of the transmission line), and the abnormality detectors 10 are arranged in a tree shape. It can also be done (see FIG. 6).

The amount of data transmitted by the abnormality detection system 100 is about several tens of bits, and the specifications are sufficiently practical even at the above transmission speed. The signals separately output from the abnormality detector 10 by the above method are converted into arbitrary transmission signals (RS485 / Ethernet (R), etc.) by the signal converter 72 and output to the host system 80. Since the transmitted signal has the property of notifying a fire or an abnormal temperature, the signal is output to the host system 80 even when the signal is transmitted from either of the two types.

<Signal transmission (signal converter → abnormality detector)>
In the abnormality detection system 100 according to the present embodiment, the signals (address / status confirmation signal, etc.) transmitted from the signal converter 72 to the abnormality detector 10 are also transmitted by using two types of methods in combination. However, there is a limit to the maximum current that can be supplied to dangerous places, and if the current for MBP transmission is supplied to all abnormality detectors 10, the number of abnormality detectors 10 connected to the cable section 90 is greatly limited. It takes. For example, the permissible output current of the FISCO power supply for the abnormality detector 10 (equipment group IIC, protection level ia) installed in the dangerous place (ZONE0) is 183 mA (@ output voltage 14 [V]), and the maximum number of connectable units is There will be 9 units. Therefore, in the first transmission method, signal transmission is performed by modulating the voltage applied to the abnormality detector 10. As an example, when the voltage applied to the abnormality detector 10 during non-transmission is 14 [V], the voltage is lowered to 10.5 V during transmission for voltage modulation (communication voltage ± 3.5 [V]). The Manchester-encoded voltage is transmitted (see FIG. 7). At this time, the applied current is a value obtained by integrating the basic current consumption required for the operation of abnormality detection by the number of installed units (for example, 1 [mA / unit] x 32 units = 32 [mA]). According to this method, it is possible to suppress the current consumption during communication on the same line as the MBP transmission line, and it is possible to increase the number of anomaly detectors 10 that can be installed. In this method, signals can be transmitted to all abnormality detectors 10 at the same time. However, the above method is an example, and a transmission method for forming a signal by high-frequency voltage modulation of 0.75 to 1.0 [V] is also possible (see FIG. 8).

In the second transmission method, differential signal transmission is used, and voltage signals having opposite phases are transmitted by two paired signal lines. In this way, the reliability of the abnormality detection system 100 can be improved by making the signal transmission redundant by two different transmission methods.

<Transmission cable>
In the present embodiment, two types of signal transmission lines 90A and 90B (for MBP and differential signal transmission) are housed in one cable section 90 (see FIG. 2). As a result, it is possible to reduce the construction cost by saving wiring and reduce the risk of incorrect cable connection. In addition, the risk of loss of intrinsic safety due to incorrect connection can be reduced. In addition, the cable portion 90 is provided with connectors on both ends so that it can be connected to the abnormality detector 10, the T-branch connector 90C, and the terminating resistor, so that the construction cost can be further reduced, resulting in erroneous connection. The risk of foreign matter entering the housing of the abnormality detector 10 can also be reduced.

<Configuration of anomaly detector>
As shown in FIG. 9, the abnormality detector 10 according to the first embodiment of the present invention is the first sensor 12 that detects infrared light in a band near 4.5 μm of the carbon dioxide resonance radiation band emitted by the flame. The second sensor 14 that detects infrared light in the band near 4.0 μm in the wavelength band shorter than the carbon dioxide resonance radiation band, and the band near 5.0 μm in the wavelength band longer than the carbon dioxide resonance radiation band. It includes a third sensor 16 that detects infrared light, and a fourth sensor 318 that detects light in a band in the vicinity of 3.0 μm, which is shorter than the above three bands, through the monitoring window 330. Further, the abnormality detector 10 includes an amplification unit 18 that amplifies the signal from the first sensor 12, an amplification unit 20 that amplifies the signal from the second sensor 14, and an amplification unit that amplifies the signal from the third sensor 16. 22, the amplification unit 322 that amplifies the signal from the fourth sensor 318, the switch 24 that switches the signal from the amplification units 18, 20, 22, and 322, and the AD conversion unit that converts the signal from the switch 24 into a digital value. It has 26 and. Further, the abnormality detector 10 includes an arithmetic processing unit 28 that performs processing for detecting a flame or an abnormal temperature, and an input / output unit 32.

The input / output unit 32 outputs to the signal converter 72 as a digital signal that the arithmetic processing unit 28 has detected a flame or an abnormal temperature, and also exchanges a digital signal with the signal converter 72.

Further, as shown in FIG. 9, the abnormality detector 10 is provided with a monitoring window 330 in a part of the housing 310A.

The first sensor 12 detects the filter 12A that transmits infrared light in the band near 4.5 μm of the carbon dioxide resonance radiation band generated by the flame and the infrared light that has passed through the filter 12A, and converts it into an electric signal of a DC component. It includes an array sensor 12B in which detection elements to be converted are arranged in a two-dimensional manner, and an optical lens 12C arranged in front of the filter 12A.

The second sensor 14 detects the filter 14A that transmits infrared light in the band near 4.0 μm in the wavelength band shorter than the carbon dioxide resonance radiation band and the infrared light that has passed through the filter 14A, and detects the electricity of the DC component. It includes an array sensor 14B in which detection elements for converting signals are arranged in a two-dimensional manner, and an optical lens 14C arranged in front of a filter 14A.

The third sensor 16 detects the filter 16A that transmits infrared light in a band near 5.0 μm in a wavelength band longer than the carbon dioxide resonance radiation band and the infrared light that has passed through the filter 16A, and detects electricity as a DC component. It includes an array sensor 16B in which detection elements for converting signals are arranged in a two-dimensional manner, and an optical lens 16C arranged in front of the filter 16A.

The fourth sensor 318 transmitted the filter 318A and the filter 318A that transmit light in a short wavelength region that is at least a part of the range including the visible light region of 4.0 μm or less among the natural light transmitted through the monitoring window 330. It includes a detection element 318B that detects light and converts it into an electric signal of a DC component.

Each detection element of the array sensor 12B is arranged so as to correspond to each detection element of the array sensor 14B and each detection element of the array sensor 16B.

Further, the array sensors 12B, 14B, 16B detect infrared light at a predetermined monitoring angle (for example, 90 degrees), and the corresponding array sensor 12B detection element, array sensor 14B detection element, And the detection element of the array sensor 16B detects infrared light from the same predetermined region.

Further, each of the optical lenses 12C, 14C, and 16C is composed of one or more lenses. It is desirable that the optical lenses 12C, 14C, and 16C are each composed of two or more lenses. This is to focus as much as possible on a flat surface with respect to a wide monitoring angle of the detection element of the array sensor 12B, the detection element of the array sensor 14B, and the detection element of the array sensor 16B. Further, in order to reduce the loss due to the reflection of the lens, it is possible to increase the sensitivity of the detection element by depositing an antireflection film (AR coat) on the lens. Lens materials include sapphire, chalcogenide glass, silicon, germanium and the like.

In addition, the same sensor as the first sensor 12 may be further provided in order to reliably capture a weak electric signal that detects infrared light in a band in the vicinity of 4.5 μm of the carbon dioxide resonance radiation band.

The detection elements of the first sensor 12 to the fourth sensor 318 are composed of thermopile, but other photoelectromotive power type elements such as InAsSb element, microbolometer element utilizing resistance change, and photoconductivity such as PbSe. It may be composed of type elements. Compared with thermopile and microbolometer, other elements have extremely high infrared detection speed. Therefore, even if the circuit configuration is the same, by increasing the AD conversion speed, it is possible to configure an abnormality detector capable of detecting a flame at an extremely high speed.

The amplification units 18, 20, 22, and 222 include an electric signal of each detection element of the first sensor 12, an electric signal of each detection element of the second sensor 14, an electric signal of each detection element of the third sensor 16, and a fourth. The electric signal of the detection element 318B of the sensor 318 is amplified independently.

The switch 24 includes a switch unit (not shown) that sequentially switches the electric signals individually amplified by the amplification units 18, 20, 22, and 222 and aggregates them into one electric signal at a fixed time. Outputs an integrated electrical signal. In addition, without providing the switch 24, an AD conversion unit is provided for each of the amplification units 18, 20, 22, and 322, and the amplified electric signal is individually converted into a digital value in the arithmetic processing unit 28. It may be output.

The arithmetic processing unit 28 is composed of a CPU. When the arithmetic processing unit 28 is described by a functional block divided for each function realizing means, as shown in FIG. 10, the arithmetic processing unit 28 includes a signal acquisition unit 40, an abnormality determination unit 44, and an input / output control unit 46. ing.

The signal acquisition unit 40 uses the signal output from the AD conversion unit 26 to obtain the value of the electric signal from each detection element of the first sensor 12, the value of the electric signal from each detection element of the second sensor 14, and the third sensor. The value of the electric signal from each of the 16 detection elements and the value of the electric signal from the detection element 318B of the fourth sensor 318 are acquired.

The abnormality determination unit 44 includes the value of the electric signal from each detection element of the first sensor 12, the value of the electric signal from each detection element of the second sensor 14, and the value of the electric signal acquired by the signal acquisition unit 40, and the third sensor 16. Based on the value of the electric signal from each detection element of the above, it is determined whether or not a flame or an abnormal temperature is detected for each detection element of the array sensor 12B. Since the determination method is the same as the method described in Patent Document (International Publication No. 2018/198504), the description thereof will be omitted.

Further, the abnormality determination unit 44 determines, among the detection elements of the array sensor 12B, a predetermined position with respect to the detection element determined to have detected the flame as a fire position.

The position predetermined with respect to the detection element may be set by measuring the detection position in the real space for each detection element by using the position measuring instrument when the abnormality detector 10 is installed.

The abnormality determination unit 44 determines the scale W, which is the spatial magnitude of the flame, based on the value of the electric signal from the detection element determined to have detected the flame.

When it is determined that a disaster has been detected, the abnormality determination unit 44 controls the input / output control unit 46 so as to notify the fire position. For example, the input / output control unit 46 transmits a fire signal to the signal converter 72 via the cable unit 90.

Further, the abnormality determination unit 44 determines that the value of the electric signal from the detection element of the third sensor 16 and the value of the electric signal from the detection element 318B of the fourth sensor 318 satisfy predetermined conditions. , The monitoring window 330, the third sensor 16, the fourth sensor 318, the amplification units 18, 20, 22, and 222, the switch 24, the AD conversion unit 26, or the arithmetic processing unit 28 are determined to be in an abnormal state, and the abnormal state is determined. The input / output control unit 46 is controlled so as to notify. For example, the input / output control unit 46 causes the signal converter 72 to transmit a signal indicating window dirt or other abnormality via the cable unit 90.

<Operation of anomaly detection system>
Next, the operation of the abnormality detection system 100 according to the first embodiment of the present invention will be described.

First, an individual address is assigned to each of the abnormality detectors 10 installed in the abnormality detection system 100. As a result, in the data transmission between the abnormality detector 10 and the signal converter 72, a signal including an address and various information is exchanged. As an example, when 32 abnormality detectors 10 are connected on the cable unit 90, the address unit is represented by 5 bits, and several bits of status information (fire signal, abnormal temperature, window dirt, fire position, etc.) are behind it. ) Is added (Fig. 11). This address can be arbitrarily changed by signal transmission from the host system 80, a DIP switch provided in the abnormality detector 10, or the like.

Further, the abnormality detector 10 repeatedly executes the process of detecting the flame or the abnormal temperature at regular intervals. Further, the abnormality detector 10 repeatedly executes the process of determining the abnormal state of the abnormality detector 10 at regular intervals.

At this time, the abnormality detection system 100 normally sends and receives the following data.

<Data transfer (normal time)>
In the abnormality detection system 100, the state of each abnormality detector 10 is normally checked in a polling format. Specifically, the signal converter 72 outputs a status information request signal to each abnormality detector 10 (each address) in order (S1), and the designated abnormality detector 10 outputs the information (address and no abnormality / Window dirt / other abnormalities, etc.) is output (S2). This is performed for each abnormality detector 10 in the order of addresses, and the state information collected when one cycle is completed is output to the host system 80. This is repeated in a fixed time cycle (Fig. 12).

By this state check, it is possible to identify the disconnection point, which will be described later. The disconnection location can be identified by the number and address of the abnormality detectors 10 that do not respond to the status information request signal from the signal converter 72.

As described above, by periodically diagnosing the functions of the abnormality detector 10 and the network and transmitting them to the host system 80, not only the reliability of the abnormality detection system 100 can be improved, but also the maintenance cost and the like can be reduced.

Further, when the abnormality detector 10 detects a flame or an abnormal temperature, or when the abnormality detector 10 is determined to be in an abnormal state, the abnormality detection system 100 exchanges the following data.

<Data transfer (when fire is detected, when abnormal temperature is detected, when abnormal condition is judged)>
When an abnormal state is detected by an arbitrary abnormality detector 10, the information (address and fire signal / abnormal temperature signal, etc.) is transmitted from the abnormality detector 10 to the signal converter 72 as shown in FIG. It is output (S3). Upon receiving this signal input, the signal converter 72 outputs a fire signal, an abnormal temperature signal, an abnormal state signal, or the like to the host system 80 (S4). In addition, the signal converter 72 outputs a signal to all the abnormality detectors 10 at the time when the information of the address portion of the above signals is transmitted from the abnormality detector 10 of the address. (S5). In response to the above signal transmission, all abnormality detectors 10 except the abnormality detector 10 stop outputting the fire signal, the abnormal temperature signal, or the abnormal state signal until after an arbitrary time, and an arbitrary time (in millisecond order) elapses. If the abnormality detector 10 that has detected the abnormality by the time is present, the fire signal, the abnormal temperature signal, or the abnormal state signal is output after the lapse of the arbitrary time. As a result, it is possible to prevent loss or communication failure due to overlapping of the signals output from the plurality of abnormality detectors 10 with a slight time difference. The above time can be arbitrarily changed according to the amount of signal to be transmitted (when the output information is only a fire signal, an abnormal temperature signal, or an abnormal state signal, it is short, and the abnormal position information, temperature information, etc. are also combined. If you want to output it, make it longer, etc.).

If the consent signal is not transmitted from the signal converter 72 even after a lapse of a certain period of time, the abnormality detector 10 outputs a fire signal or the like again and repeatedly executes this until the consent signal is transmitted. If a fire signal or the like is output from two or more abnormality detectors 10 at the same time, or if a fire signal or the like is output from an arbitrary abnormality detector 10 during the status check of the abnormality detector 10, 2 A signal obtained by synthesizing one or more signals is input to the signal converter 72 (FIG. 14). In this case, depending on the conditions, the signal cannot be restored and may be lost. Therefore, the status of each abnormality detector 10 is checked in a polling format. Specifically, as shown in FIG. 15, when it is determined that the signal converter 72 has output from a plurality of abnormality detectors 10, the address and status information request signals are sequentially sent to all the abnormality detectors 10. Is output (S6), and each designated abnormality detector 10 outputs the information (address and no abnormality / fire signal, etc.) (S7). This is performed for each abnormality detector 10 in the order of addresses, and when a fire signal, an abnormal temperature signal, or an abnormal state signal is confirmed, the information is output to the host system 80 (S8). As a method for determining that the signal converter 72 has output from a plurality of abnormality detectors 10, for example, in MBP transmission, a method of monitoring the output current from the power supply and making a determination based on the amount of increase in the current is used. is there. On the other hand, regarding balanced differential signal transmission, although there is a method of determining by increasing the amplitude of the signal input to the signal converter 72, it becomes difficult to determine when the signals completely overlap.

Therefore, when any signal is input by the transmission method, reliable transmission is performed by checking the state of each abnormality detector 10 in a polling format in the same manner as the above MBP. However, this method is an example, and is a method of adjusting the line usage right by monitoring the status of signals flowing through the cable section 90 between abnormality detectors 10 such as carrier wave detection multiple access / collision detection (CSMA / CD). Is also applicable. As described above, by using polling that is simple and has high transmission reliability, it is possible to prevent the loss of the fire signal from the abnormality detector 10 and the communication failure, and improve the reliability of data transfer in both transmission methods.

<Countermeasures against disconnection / short circuit>
If a wire break or short circuit occurs in the cable section 90, there is a possibility that an arbitrary abnormality detector 10 may not be able to monitor (a state in which power is not supplied, a state in which signal transmission is not performed, etc.) (FIG. 16). .. The abnormality detection system 100 monitors disconnection and short circuit by the following method, and outputs a disconnection / short circuit alarm to the host system 80.

(Disconnection monitoring)
In the abnormality detection system 100, as described above, the state check of the abnormality detector 10 is performed at regular intervals. Therefore, if there is no response to the state information request signal from the signal converter 72, it is suspected that a disconnection has occurred. Here, since a unique address is assigned to the abnormality detector 10, as shown in FIG. 16A, when a disconnection occurs on the cable portion 90, or as shown in FIG. 16B. In addition, when a disconnection occurs on the branch line of the cable portion 90, the signal converter 72 can identify the disconnection location based on the address where there is no response after one cycle of the state check.

(Short circuit monitoring)
In the abnormality detection system 100, when a short circuit occurs on the cable portion 90 as shown in FIG. 16C, or when a short circuit occurs on the branch line of the cable portion 90 as shown in FIG. 16B. Although the short-circuit location cannot be specified, the short-circuit can be detected by monitoring the short-circuit current with the signal converter 72 or the power supply unit 74.

As described above, according to the abnormality detection system according to the embodiment of the present invention, each of the input / output unit and the signal converter of the abnormality detector uses different signal transmission methods on a plurality of signal transmission lines. By exchanging and exchanging the digital signal, it is possible to provide a highly reliable abnormality detection system with a simple configuration.

In addition, the cable section including multiple signal transmission lines reliably transmits the fire or abnormal temperature detected by the abnormality detector to the higher-level system even if a problem (disconnection or short circuit) occurs in the cable section, and the safety level. A high-quality abnormality detection system can be realized.

In addition, a fire / abnormal temperature monitoring environment at a dangerous place (ZONE0), which has the strictest technical requirements, can be realized at low cost.

In addition, multiple anomaly detectors installed at dangerous locations are connected to a single cable with a T-branch, and are half-duplexed with the host system via barriers and signal converters installed at non-dangerous locations. Communicate. Specifically, the signals transmitted from the abnormality detector to the signal converter (unique address / fire signal / abnormal temperature signal / state information, etc.) are the current signal supplied by the Manchester coded bus and the balanced differential signal transmission. It is redundantly transmitted as two types of signals of the voltage signal by. The signals (address / status confirmation signal, etc.) transmitted from the signal converter to the abnormality detector are two: voltage transmission generated by modulation of the voltage applied to the abnormality detector and voltage signal by differential signal transmission. It is transmitted as a kind of signal in a redundant manner. As a result, the fire signal or the abnormal temperature can be reliably transmitted to the host system.

Further, by using the voltage transmission by the voltage modulation, it is possible to suppress the current supplied to the dangerous place, and it is possible to increase the number of abnormality detectors installed in the dangerous place.

Further, by carrying out each of the two types of signal transmission at a low transmission speed of about several tens of kbps, a network capable of tree branching can be obtained.

Further, the construction cost can be reduced by accommodating the above two types of signal transmission lines in one cable section.

In addition, by polling from the signal converter, the functions of the abnormality detector and the network are periodically diagnosed and transmitted to the host system, thereby improving the reliability of the abnormality detection system and reducing the maintenance cost and the like.

Further, when a fire signal or the like is output simultaneously from a plurality of abnormality detectors, polling from the signal converter prevents communication failure of the fire signal and improves reliability for data transfer.

[Second Embodiment]
<System configuration>
Hereinafter, the abnormality detection system according to the second embodiment of the present invention will be described. The parts having the same configuration as that of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 17, the abnormality detection system 200 according to the second embodiment of the present invention includes a plurality of abnormality detectors 10, barriers 70A and 70B, signal converters 72A and 72B, and a power supply unit 74A. It is equipped with 74B and a higher-level system 80.

The signal converter 72A and the plurality of abnormality detectors 10 are connected by a cable unit 290A, and the signal converter 72B and the plurality of abnormality detectors 10 are connected by a cable unit 290B.

As described above, in the present embodiment, the first medium configuration including the cable unit 290A, the power supply unit 74A, the signal converter 72A, and the barrier 70A, and the cable unit 290B, the power supply unit 74B, the signal converter 72B, and the barrier A second neutral configuration, including 70B, is provided. In accordance with this, each abnormality detector 10 includes two input / output units 32, and one input / output unit 32 is connected to the first intermediate configuration and is connected to the first intermediate configuration by the arithmetic processing unit 28 via the cable unit 290A. The detection of a flame is output as a digital signal to the signal converter 72A, and a digital signal is exchanged with the signal converter 72A. Further, the other input / output unit 32 is connected to the second medium configuration, and outputs the detection of the flame by the arithmetic processing unit 28 as a digital signal to the signal converter 72B via the cable unit 290B, and also outputs a signal. It sends and receives digital signals to and from the converter 72B.

The cable portions 290A and 290B include a signal transmission line 90A and a signal transmission line 90B, similarly to the cable portion 90 of the first embodiment.

In the abnormality detection system 200, the lines from the cable units 290A and 290B to the power supply units 74A and 74B are duplicated. By duplicating the network in this way, it is possible to avoid a state in which monitoring becomes impossible in the event of a disconnection or short circuit (FIG. 18). Specifically, when a disconnection / short circuit in one network is detected by the signal converter 72A or 72B by the same method as in the first embodiment, a short circuit alarm is output to the host system 80 and transmission is performed. Automatically switch lines to the other network. As a result, it is possible to avoid a state in which fire / abnormal temperature monitoring becomes impossible due to disconnection or short circuit, and a highly reliable fire monitoring environment can be constructed.

Since a unique address is assigned to the abnormality detector 10, as shown in FIG. 18 (A), when a disconnection occurs on the cable portion 290B or as shown in FIG. 18 (B). When a disconnection occurs on the branch line of the cable portion 290B, the signal converter 72B can identify the disconnection location based on the address where there is no response after one cycle of the state check. Further, as shown in FIG. 18C, when a short circuit occurs on the cable portion 290B, or as shown in FIG. 18B, when a short circuit occurs on the branch line of the cable portion 290B, the short circuit occurs. Although the location cannot be specified, a short circuit can be detected by monitoring the short circuit current with the signal converter 72B or the power supply unit 74B.

As described above, according to the abnormality detection system according to the second embodiment, the line from the cable unit to the power supply unit can be duplicated to further make it redundant, and for fire or abnormal temperature monitoring. Realize a highly reliable network at low cost. In this case, it is a quadruple system in terms of signal transmission. Due to the duplication, even if a disconnection or short circuit occurs, the fire or abnormal temperature monitoring environment can be continued. In actual operation, it is also possible to use an abnormality detector with two cable connection connectors as a standard product, and to select the presence or absence of duplication according to the safety level (SIL) and cost required by the customer. Is.

<Modification example>
The present invention is not limited to the above-described embodiment, and various modifications and applications are possible without departing from the gist of the present invention.

For example, the case where an array sensor is used in all of the first sensor 12, the second sensor 14, and the third sensor 16 of the abnormality detector 10 has been described as an example, but the present invention is not limited thereto. An array sensor may be used in at least one of the first sensor 12, the second sensor 14, and the third sensor 16. For example, the first sensor 12 may be configured by using the array sensor 12B, and the second sensor 14 and the third sensor 16 may be configured by using one detection element instead of the array sensor.

Further, the first sensor 12, the second sensor 14, and the third sensor 16 are configured by using one detection element instead of the array sensor, and infrared light in the band from around 2.0 μm to around 5.0 μm. The fifth sensor may be configured to further include a fifth sensor for detecting the above, and the fifth sensor may be configured by using an array sensor. In this case, the abnormality determination unit is in a predetermined position with respect to the detection element having the maximum electric signal value based on the electric signal value detected by each detection element of the array sensor of the fifth sensor. Should be determined as the fire position.

Further, the present invention may be applied to a system such as a gas detector or a temperature sensor that outputs an alarm indicating that a predetermined abnormality has been detected at a predetermined threshold value or higher. Further, as the abnormality detector, the present invention may be applied to an abnormality detection system using a field device in which a plurality of units are installed in a row at a dangerous place.

Further, the case where MBP is used as the first transmission method has been described as an example, but the present invention is not limited to this, and for example, Manchester code by voltage modulation or Ethernet (registered trademark) may be used. When Ethernet (registered trademark) is used as the first transmission method, power can be supplied by a communication line using a technology called PoE (Power over Ethernet).

10 Anomaly detector 28 Arithmetic processing unit 32 Input / output unit 70, 70A, 70B Barrier 72, 72A, 72B Signal converter 74, 74A, 74B Power supply unit 80 Upper system 90, 290A, 290B Cable unit 90A, 90B Signal transmission line 100 , 200 Anomaly detection system

Claims (14)

Based on the sensor information detected by the sensor, an abnormality determination unit that determines whether or not a predetermined abnormality has been detected, and the determination result by the abnormality determination unit are output as a digital signal to the signal converter and the signal conversion. Anomaly detectors that include an input / output unit that sends and receives digital signals to and from the device,
A signal converter that relays the transmission and reception of signals between the abnormality detector and the host device, and
A power supply unit that supplies power to the abnormality detector,
A plurality of signal transmission lines for transmitting the digital signal provided so as to connect between the signal converter and the input / output unit are included, and the abnormality detector is provided from the power supply unit. The transmission cable section that supplies power and
Including
Each of the input / output unit and the signal converter transmits / receives the digital signal on the plurality of signal transmission lines using different signal transmission methods.
Anomaly detection system. Each of the input / output unit and the signal converter uses the digital signal generated by modulation of the voltage applied to the input / output unit or the amplitude of the voltage as one of the signal transmission methods, and the digital signal is used. The abnormality detection system according to claim 1, wherein signals are sent and received. Each of the input / output unit and the signal converter uses the digital signal generated by modulating the current flowing from the input / output unit to the signal converter as one of the signal transmission methods, and uses the digital signal. The abnormality detection system according to claim 1 or 2, which sends and receives signals. Claims 1 to claim that each of the input / output unit and the signal converter uses Ethernet (registered trademark) as one of the signal transmission methods to transfer the digital signal and supply the power. Item 3. The abnormality detection system according to any one of items 3. The abnormality detection system according to any one of claims 1 to 4, wherein the transmission cable unit includes one transmission cable containing the plurality of signal transmission lines. The one according to any one of claims 1 to 5, further comprising a barrier unit provided between the input / output unit and the signal converter for limiting the current and voltage supplied from the power supply unit. Anomaly detection system. The abnormality detectors are a plurality of abnormality detectors, each of which is connected to the transmission cable unit.
The abnormality detection system according to any one of claims 1 to 6, wherein each of the plurality of abnormality detectors performs bidirectional communication with the signal converter. A unique address is assigned to each of the plurality of abnormality detectors in advance.
The abnormality detection system according to claim 7, wherein the digital signal transmitted and received between the abnormality detector and the signal converter includes an address of the abnormality detector. The signal converter monitors the state of each abnormality detector, the state of the transmission cable unit, and the determination result in order by polling at regular time intervals, and the state of the abnormality detector or the state of the transmission cable unit is abnormal. When it is in a state, or when the determination result indicates that the predetermined abnormality has been detected, or when the digital signal of the determination result indicating that the predetermined abnormality has been detected is output from the abnormality detector. The abnormality detection system according to claim 7 or 8, wherein a predetermined message is transmitted to a higher-level device. The signal converter is a digital signal indicating that the state of the abnormality detector is in an abnormal state from two or more abnormality detectors, or the digital signal indicating that the determination result has detected the predetermined abnormality. The abnormality detection system according to any one of claims 7 to 9, which monitors the status and determination result of each abnormality detector in order when a signal is output, and transmits the monitoring result to a higher-level device. The abnormality detection system according to claim 9, wherein the abnormal state of the transmission cable unit is a disconnection or short circuit of the signal transmission line or the power cable. The abnormality detector includes a plurality of input / output units.
A plurality of medium configurations including the transmission cable unit, the power supply unit, and the signal converter are provided.
The abnormality according to any one of claims 1 to 11, wherein a digital signal is exchanged using any one of the plurality of input / output units and any one of the plurality of intermediate configurations. Detection system. Any of claims 1 to 12, wherein the abnormality determination unit determines whether or not a flame, an abnormality temperature, an abnormality position, a window stain, or an abnormality of the abnormality detector is detected as the predetermined abnormality. The abnormality detection system described in item 1. The abnormality detector is
A first band filter that transmits infrared light in the first band including the peak wavelength of the carbon dioxide resonance radiation band,
A second band filter that transmits infrared light in a second band different from the first band and whose center of the band is located away from the center of the carbon dioxide resonance radiation band, and the first band and A plurality of band filters including a third band filter provided at a position where the band center is distant from the band center of the carbon dioxide resonance radiation band while transmitting infrared light of a third band different from the second band. ,
A detection unit provided for each of the plurality of band filters and including a detection element for detecting infrared light transmitted through the band filters and converting the infrared light into an electric signal, and at least one of the plurality of band filters. The detection elements provided for each of them are a detection unit configured as an array sensor arranged in a two-dimensional manner and a detection unit.
An abnormality determination unit that determines whether a flame or an abnormality temperature has been detected based on the electrical signal detected by each detection element.
13. The anomaly detection system according to claim 13.

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