Sensor Systems

Abstract

To detect the wiring abnormality and internal abnormality of a sensor without having to add a load, as compared with a conventional structure.SOLUTION: An abnormality detection device 3 comprises: a first output circuit 301 for outputting a detection signal; a second output circuit 302 for outputting an abnormality detection signal; an exclusive-OR circuit 303 for outputting a signal that indicates the computation result of exclusive-OR of the detection signal and the abnormality detection signal; a power supply 304; a first switching element 305 for switching electrical continuity in accordance with the detection signal outputted from the first output circuit; a second switching element 306 for switching electrical continuity in accordance with the detection signal outputted from the exclusive-OR circuit; a first load 307; a second load 308; and a detection unit 309 for detecting, on the basis of the states of the first and the second loads, the abnormality of a power supply wiring 311, a first output wiring 313, a second output wiring 314 and a ground wiring 312 and / or the internal abnormality of the sensor 1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004] , ,

[0005] , , ,

[0001] This invention relates to an abnormality detection device and a sensor system including the abnormality detection device.

Background Art

[0002] Conventionally, when a wiring abnormality such as a disconnection or a short circuit occurs in a conducting wire used inside a sensor, a sensor configured to be able to detect the wiring abnormality based on the states of a first load and a second load connected to the conducting wire has been known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the sensor of Patent Document 1 above, although it is possible to detect a wiring abnormality of the sensor, it is not possible to detect an abnormality occurring inside the sensor (hereinafter referred to as an internal abnormality). Therefore, the user may require a lot of time until noticing the internal abnormality. Also, when a large number of sensors are used inside a certain device, even if an internal abnormality occurs in any one of the sensors, it may require a lot of time to identify the abnormal location. Thus, in contrast to the conventional sensor configuration described in Patent Document 1 above, it is conceivable to incorporate means for detecting the internal abnormality (for example, a known internal abnormality detection circuit) to detect not only the wiring abnormality of the sensor but also the internal abnormality.

[0005] However, since the conventional sensor described in Patent Document 1 above is configured for the purpose of detecting wiring abnormalities in the sensor, it is conceivable that in order to detect internal abnormalities in addition to wiring abnormalities, it may be necessary to add an additional load for detecting internal abnormalities in addition to the first and second loads.

[0006] This invention was made to solve the above-mentioned problems, and aims to provide an abnormality detection device that can detect both wiring abnormalities and internal abnormalities of sensors without adding any load to the conventional configuration. [Means for solving the problem]

[0007] The abnormality detection device according to this invention includes a first output circuit that outputs a detection signal indicating the presence or absence of a detected object obtained by a sensor, a second output circuit that outputs an abnormality detection signal indicating the presence or absence of an internal abnormality in the sensor, an exclusive OR circuit that outputs a signal indicating the result of calculating the exclusive OR of the detection signal output by the first output circuit and the abnormality detection signal output by the second output circuit, a power supply with its positive terminal connected to the power supply wiring and its negative terminal connected to the ground wiring, and a circuit with one end connected to the power supply wiring and the other end connected to one end of the first output wiring, which switches the conduction state according to the detection signal output by the first output circuit. The system comprises a first switching element, a second switching element with one end connected to a power supply wire and the other end connected to one end of a second output wire, which switches its conduction state according to a signal output by an exclusive OR circuit, a first load with one end connected to the other end of the first output wire and the other end connected to a ground wire, a second load with one end connected to the other end of the second output wire and the other end connected to a ground wire, and a detection unit that detects at least one of abnormalities in the power supply wire, the first output wire, the second output wire, and the ground wire, as well as an internal abnormality of the sensor, based on the state of the first load and the state of the second load.

[0008] Furthermore, the abnormality detection device according to this invention includes a first output circuit that outputs a detection signal indicating the presence or absence of a detected object obtained by a sensor, a second output circuit that outputs an abnormality detection signal indicating the presence or absence of an internal abnormality in the sensor, an exclusive OR circuit that outputs a signal indicating the result of calculating the exclusive OR of the detection signal output by the first output circuit and the abnormality detection signal output by the second output circuit, a power supply with its positive terminal connected to a power supply wire and its negative terminal connected to a ground wire, and a circuit with one end connected to a ground wire and the other end connected to one end of the first output wire, which maintains a conduction state according to the detection signal output by the first output circuit. The system comprises a first switching element that performs switching, a second switching element with one end connected to a ground wire and the other end connected to one end of a second output wire, which switches its conduction state according to a signal output by an exclusive OR circuit, a first load with one end connected to the other end of the first output wire and the other end connected to a power supply wire, a second load with one end connected to the other end of the second output wire and the other end connected to a power supply wire, and a detection unit that detects at least one of abnormalities in the power supply wire, the first output wire, the second output wire, and the ground wire, as well as an internal abnormality of the sensor, based on the state of the first load and the state of the second load. [Effects of the Invention]

[0009] According to this invention, with the configuration described above, it becomes possible to detect both wiring abnormalities and internal abnormalities of the sensor without adding any load compared to the conventional configuration. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an example configuration of an anomaly detection device and a sensor system equipped with an anomaly detection device according to Embodiment 1. [Figure 2] This diagram illustrates wiring abnormalities and internal abnormalities in Embodiment 1, as well as the signal values ​​in each state. [Modes for carrying out the invention]

[0011] The embodiments of this invention will be described in detail below with reference to the drawings. Embodiment 1. Figure 1 shows an example configuration of an anomaly detection device 3 according to Embodiment 1 and a sensor system equipped with this anomaly detection device 3.

[0012] The sensor system according to Embodiment 1, as shown in Figure 1, is configured to include a sensor 1 and an anomaly detection device 3. Sensor 1 detects the presence or absence of a target object and outputs a signal (detection signal) indicating the detection result. Sensor 1 is composed of, for example, a proximity sensor or a photoelectric sensor, and is equipped with a target object detection unit 2 as its main component.

[0013] If the sensor 1 is a high-frequency oscillation type proximity sensor, the detection unit 2 has, for example, an oscillation circuit including a detection coil, a capacitor, and a nonlinear amplifier. If the sensor 1 is a photoelectric sensor, the detection unit 2 has, for example, a light-emitting unit, a light-receiving unit, a detection circuit, and a signal output circuit. In either case, the method for detecting the presence or absence of a detection object by the detection unit 2 is known, so a detailed explanation is omitted.

[0014] Furthermore, the detection unit 2 includes an abnormality detection circuit (not shown) that detects internal abnormalities in the sensor 1. The abnormality detection circuit detects internal abnormalities in the sensor 1 and outputs an abnormality detection signal indicating the detection result. For example, if the sensor 1 is a proximity sensor, the abnormality detection circuit will detect an internal abnormality in the sensor 1 when the coil wire of the detection coil is broken or short-circuited, or when an abnormality occurs in the memory (EEPROM, etc.) used inside the sensor 1, and will output an abnormality detection signal indicating that there is an internal abnormality. Conventional abnormality detection circuits can be used as this abnormality detection circuit.

[0015] The anomaly detection device 3 comprises a first output circuit 301, a second output circuit 302, an exclusive OR circuit 303, a power supply 304, a first switching element 305, a second switching element 306, a first load 307, a second load 308, and a detection unit 309. Here, as an example, we will describe an arrangement in which the first output circuit 301, the second output circuit 302, the exclusive OR circuit 303, the first switching element 305, and the second switching element 306 are provided inside the housing of the sensor 1, while the power supply 304, the first load 307, and the second load 308 are provided outside the housing of the sensor 1. However, this arrangement is merely an example, and the arrangement of each component is not limited to this.

[0016] The first output circuit 301 acquires a detection signal indicating the presence or absence of a detected object from the object detection unit 2 (sensor 1) and outputs the acquired detection signal. That is, the first output circuit 301 outputs the detection signal indicating the presence or absence of a detected object obtained by the object detection unit 2 (sensor 1) from its output terminal. The output terminal of the first output circuit 301 is connected to the first input terminal (indicated by A in Figure 1) of the exclusive OR circuit 303 and to the base terminal of the first switching element 305.

[0017] The second output circuit 302 acquires an abnormality detection signal from the sensor detection unit 2 (sensor 1) indicating the presence or absence of an internal abnormality in sensor 1, and outputs the acquired abnormality detection signal from its output terminal. The output terminal of the second output circuit 302 is connected to the second input terminal (indicated as B in Figure 1) of the exclusive OR circuit 303.

[0018] The exclusive OR circuit 303 includes a first input terminal A, a second input terminal B, and an output terminal (indicated as Z in Figure 1). The exclusive OR circuit 303 calculates the exclusive OR (XOR) of the detection signal input from the first output circuit 301 via the first input terminal A and the abnormality detection signal input from the second output circuit 302 via the second input terminal B, and outputs a signal indicating the calculation result from the output terminal Z.

[0019] The power supply 304 has its positive terminal connected to the power supply wiring 311 and its negative terminal connected to the ground wiring 312.

[0020] The first switching element 305 is composed of, for example, a first PNP transistor. One end of the first switching element 305 is connected to the power supply wiring 311, and the other end is connected to one end of the first output wiring 313. Specifically, when the first switching element 305 is composed of a first PNP transistor, the emitter terminal is connected to the power supply wiring 311, and the collector terminal is connected to one end of the first output wiring 313. Also, the base terminal of the first switching element 305 is connected to the output terminal of the first output circuit 301. Then, the first switching element 305 switches its conduction state according to the detection signal input from the output terminal of the first output circuit 301 to the base terminal.

[0021] The second switching element 306 is composed of, for example, a second PNP transistor. One end of the second switching element 306 is connected to the power supply wiring 311, and the other end is connected to one end of the second output wiring 314. Specifically, when the second switching element 306 is composed of a second PNP transistor, the emitter terminal is connected to the power supply wiring 311, and the collector terminal is connected to one end of the second output wiring 314. Also, the base terminal of the second switching element 306 is connected to the output terminal Z of the exclusive OR circuit 303. Then, the second switching element 306 switches its conduction state according to the signal input from the output terminal Z of the exclusive OR circuit 303 to the base terminal.

[0022] One end of the first load 307 is connected to the other end of the first output wiring 313, and the other end is connected to the ground wiring 312. Also, one end of the second load 308 is connected to the other end of the second output wiring 314, and the other end is connected to the ground wiring 312. Note that the ground wiring 312 is also connected to the internal circuit (not shown) of the sensor 1.

[0023] The detection unit 309 is connected to the first load 307 and the second load 308, and can acquire the states of both loads. The detection unit 309 detects at least one of an abnormality in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312, and an internal abnormality of the sensor 1 based on the states of the first load 307 and the second load 308. Here, the abnormality in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312 refers to a disconnection of each of these wirings and a short circuit between any two of these wirings.

[0024] Specifically, the detection unit 309 determines that there is no abnormality when the state of the first load 307 and the state of the second load 308 are inverted from each other. On the other hand, when the state of the first load 307 and the state of the second load 308 are the same, the detection unit 309 detects at least one of an abnormality in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312, and an internal abnormality of the sensor 1.

[0025] In addition, when the states of the first load 307 and the second load 308 change from a state where they are inverted from each other to the same state in response to the detection signal and the abnormality detection signal, the detection unit 309 detects an abnormality in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312.

[0026] Note that the function of the detection unit 309 is realized, for example, by a CPU (Central Processing Unit) provided in a monitoring device (not shown) executing a predetermined program developed in a memory (not shown).

[0027] Next, an operation example of the abnormality detection device 3 according to Embodiment 1 will be described with reference to FIG. 2. FIG. 2 is a diagram for explaining an internal abnormality and a wiring abnormality in Embodiment 1 and signal values in each of these states.

[0028] For the sake of clarity, the detection unit 2 (sensor 1) will be assumed to output a detection signal of 1 (High) when an object is detected and a detection signal of 0 (Low) when no object is detected. Furthermore, the detection unit 2 (sensor 1) will be assumed to output an abnormality detection signal of 1 (High) when there is no internal abnormality in sensor 1 and an abnormality detection signal of 0 (Low) when there is an internal abnormality in sensor 1.

[0029] Furthermore, when a signal of 1 (High) is output, it means that current flows in the direction of the signal's output, and when a signal of 0 (Low) is output, it means that no current flows in the direction of the signal's output. Also, the initial state of both the first and second loads is assumed to be a state where 0 (Low) is applied. The signal output from the output terminal Z of the exclusive OR circuit 303 is denoted as z.

[0030] (1. If Sensor 1 is functioning correctly) (1-a. If a detection sample is present) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0031] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0032] Since the detection signal (1) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, no current flows from the base terminal to the first output circuit 301, and no current flows between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 is in a non-conducting state. Therefore, the first load 307 is maintained in a state where 0 is applied.

[0033] The exclusive OR circuit 303 receives a detection signal (1) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 0, which represents the result of the calculation. This signal z is input to the base terminal of the second PNP transistor 306.

[0034] The signal z(0) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306. As a result, current flows from the base terminal to the exclusive OR circuit 303, and also between the emitter and collector terminals. In other words, the second PNP transistor 306 becomes conductive. Therefore, the second output wire 314 outputs 1 as the second output signal, and the second output signal (1) is applied to the second load 308.

[0035] The detection unit 309 acquires the state of the first load 307 (0 indicates application) and the state of the second load 308 (1 indicates application). The detection unit 309 determines that there is no abnormality because the states of both loads are inversely related.

[0036] Furthermore, the detection unit 309 may display the results of the anomaly detection on a monitor (not shown) provided by the monitoring device and present them to the user. This also applies to the following explanation.

[0037] (1-b. If no detectable organism is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0038] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0039] The detection signal (0) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, causing current to flow from the base terminal towards the first output circuit 301, and also between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 becomes conductive. Therefore, the first output wire 313 outputs 1 as the first output signal, and the first output signal (1) is applied to the first load 307.

[0040] The exclusive OR circuit 303 receives a detection signal (0) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 1, which represents the result of the calculation. This signal z is input to the base terminal of the second PNP transistor 306.

[0041] Since the signal z(1) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306, no current flows from the base terminal to the exclusive OR circuit 303, and no current flows between the emitter terminal and the collector terminal. In other words, the second PNP transistor 306 is in a non-conducting state. Therefore, the second load 308 is maintained in a state where 0 is applied.

[0042] The detection unit 309 acquires the state of the first load 307 (1 indicates application) and the state of the second load 308 (0 indicates application). The detection unit 309 determines that there is no abnormality because the states of both loads are inversely related.

[0043] (2. If there is an internal abnormality in sensor 1) (2-a. If a detection sample is present) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 0 (Low) as an anomaly detection signal.

[0044] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0045] Since the detection signal (1) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, no current flows from the base terminal to the first output circuit 301, and no current flows between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 is in a non-conducting state. Therefore, the first load 307 is maintained in a state where 0 is applied.

[0046] The exclusive OR circuit 303 receives a detection signal (1) from the first input terminal A and an abnormality detection signal (0) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 1, which represents the result of the calculation. This signal z (1) is input to the base terminal of the second PNP transistor 306.

[0047] Since the signal z(1) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306, no current flows from the base terminal to the exclusive OR circuit 303, and no current flows between the emitter terminal and the collector terminal. In other words, the second PNP transistor 306 is in a non-conducting state. Therefore, the second load 308 is maintained in a state where 0 is applied.

[0048] The detection unit 309 acquires the state of the first load 307 (0 is applied) and the state of the second load 308 (0 is applied), and since the states of both are the same, it determines that there is an abnormality.

[0049] (2-b. If no detectable organism is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 0 (Low) as an anomaly detection signal.

[0050] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0051] The detection signal (0) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, causing current to flow from the base terminal towards the first output circuit 301, and also between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 becomes conductive. Therefore, the first output wire 313 outputs 1 as the first output signal, and the first output signal (1) is applied to the first load 307.

[0052] The exclusive OR circuit 303 receives a detection signal (0) from the first input terminal A and an abnormality detection signal (0) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 0, which represents the result of the calculation. This signal z (0) is input to the base terminal of the second PNP transistor 306.

[0053] The signal z(0) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306. As a result, current flows from the base terminal to the exclusive OR circuit 303, and also between the emitter and collector terminals. In other words, the second PNP transistor 306 becomes conductive. Therefore, the second output wire 314 outputs 1 as the second output signal, and the second output signal (1) is applied to the second load 308.

[0054] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (1 applied), and since the states of both are the same, it determines that there is an abnormality.

[0055] (3. If there is no internal abnormality in sensor 1 and the power supply wiring 311 is broken) For example, if the power supply wiring 311 is broken at the location indicated by the symbol a in Figure 1, the power supply to the first PNP transistor 305 and the second PNP transistor 306 will be cut off. Therefore, in this case, regardless of the presence or absence of the detection body, both the first PNP transistor 305 and the second PNP transistor 306 will be in a non-conductive state, and the state of both the first load 307 and the second load 308 will remain in a state where 0 is applied. The detection unit 309 acquires the state of the first load 307 (0 applied) and the state of the second load 308 (0 applied), and since the states of both are the same, it determines that there is an abnormality.

[0056] (4. If there is no internal abnormality in sensor 1 and the ground wiring 312 is broken) For example, if the ground wiring 312 is broken at the location indicated by the symbol b in Figure 1, the power supply to the first PNP transistor 305 and the second PNP transistor 306 will be cut off. Therefore, in this case as well, regardless of the presence or absence of the detection body, both the first PNP transistor 305 and the second PNP transistor 306 will be in a non-conductive state, and the state of both the first load 307 and the second load 308 will remain in a state where 0 is applied. The detection unit 309 acquires the state of the first load 307 (0 applied) and the state of the second load 308 (0 applied), and since the states of both are the same, it determines that there is an abnormality.

[0057] (5. If there is no internal abnormality in sensor 1 and the first output wiring 313 is broken) For example, suppose the first output wiring 313 is broken at the location indicated by the symbol c in Figure 1.

[0058] (5-a. If a substance is detected) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0059] Here, since the first output wiring 313 is broken at the location indicated by the symbol c in Figure 1, the state of the first load 307 does not change regardless of whether or not a detection object is present. Therefore, the first load 307 is maintained in a state where 0 is applied.

[0060] The exclusive OR circuit 303 receives a detection signal (1) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 0, which represents the result of the calculation. This signal z (0) is input to the base terminal of the second PNP transistor 306.

[0061] The signal z(0) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306. As a result, current flows from the base terminal to the exclusive OR circuit 303, and also between the emitter and collector terminals. In other words, the second PNP transistor 306 becomes conductive. Therefore, the second output wire 314 outputs 1 as the second output signal, and the second output signal (1) is applied to the second load 308.

[0062] The detection unit 309 acquires the state of the first load 307 (0 is applied) and the state of the second load 308 (1 is applied). The detection unit 309 determines that there is no abnormality because the states of the two loads are inversely related. In other words, the detection unit 309 cannot determine that there is an abnormality even if the first output wiring 313 is broken, as long as there is a detected object. However, the detection unit 309 can determine that there is an abnormality when there is a change in the detection state of the detected object, that is, when the state changes from when there is a detected object to when there is no detected object.

[0063] (5-b. If no detection material is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0064] Here, since the first output wiring 313 is broken at the location indicated by the symbol c in Figure 1, the state of the first load 307 does not change regardless of whether or not a detection object is present. Therefore, the first load 307 is maintained in a state where 0 is applied.

[0065] The exclusive OR circuit 303 receives a detection signal (0) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 1, which represents the result of the calculation. This signal z (1) is input to the base terminal of the second PNP transistor 306.

[0066] Since the signal z(1) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306, no current flows from the base terminal to the exclusive OR circuit 303, and no current flows between the emitter terminal and the collector terminal. In other words, the second PNP transistor 306 is in a non-conducting state. Therefore, the second load 308 is maintained in a state where 0 is applied.

[0067] The detection unit 309 acquires the state of the first load 307 (0 is applied) and the state of the second load 308 (0 is applied), and since the states of both loads are the same, it determines that there is an abnormality.

[0068] Normally, the detection state of the detected object by sensor 1 (detection unit 2) is expected to change continuously. Therefore, even if the detection unit 309 initially determines that there is no abnormality, it can quickly detect an abnormality (determine that there is an abnormality) if the detection state of the detected object changes afterward.

[0069] (6. If there is no internal abnormality in sensor 1 and the second output wiring 314 is broken) For example, suppose the second output wiring 314 is broken at the location indicated by the symbol d in Figure 1.

[0070] (6. If no detection is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0071] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0072] The detection signal (0) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, causing current to flow from the base terminal towards the first output circuit 301, and also between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 becomes conductive. Therefore, the first output wire 313 outputs 1 as the first output signal, and the first output signal (1) is applied to the first load 307.

[0073] Here, since the second output wiring 314 is broken at the location indicated by the symbol d in Figure 1, the state of the second load 308 does not change regardless of whether or not a detection object is present. Therefore, the second load 308 is maintained in a state where 0 is applied.

[0074] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (0 applied), and since the states of both loads are reversed, it determines that there is no abnormality. In other words, the detection unit 309 cannot determine that there is an abnormality even if the second output wiring 314 is broken when there is no object to detect. However, the detection unit 309 can determine that there is an abnormality when there is a change in the detection state, that is, when the state changes from a state with no object to a state with an object to detect.

[0075] (6-b. If a detectable substance is present) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0076] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0077] Since the detection signal (1) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, no current flows from the base terminal to the first output circuit 301, and no current flows between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 is in a non-conducting state. Therefore, the first load 307 is maintained in a state where 0 is applied.

[0078] Here, since the second output wiring 314 is broken at the location indicated by the symbol d in Figure 1, the state of the second load 308 does not change regardless of whether or not a detection object is present. Therefore, the second load 308 is maintained in a state where 0 is applied.

[0079] The detection unit 309 acquires the state of the first load 307 (0 is applied) and the state of the second load 308 (0 is applied), and since the states of both loads are the same, it determines that there is an abnormality.

[0080] (7. If there is no internal abnormality in sensor 1 and the power supply wiring 311 and the ground wiring 312 are short-circuited) For example, suppose that the power supply wiring 311 and the ground wiring 312 are short-circuited between symbols a and b. In this case, the power supply to the first PNP transistor 305 and the second PNP transistor 306 is stopped. Therefore, in this case, regardless of the presence or absence of the detection body, both the first PNP transistor 305 and the second PNP transistor 306 become non-conductive, and the state of both the first load 307 and the second load 308 is maintained as if a value of 0 were applied. The detection unit 309 acquires the state of the first load 307 (a value of 0 applied) and the state of the second load 308 (a value of 0 applied), and since the states of both are the same, it determines that there is an abnormality.

[0081] (8. If there is no internal abnormality in sensor 1 and the power supply wiring 311 and the first output wiring 313 are short-circuited) For example, assume that the power supply wiring 311 and the first output wiring 313 are short-circuited between the sign ac.

[0082] (8. If no detection is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0083] Here, since the power supply wiring 311 and the first output wiring 313 are short-circuited between the signs ac and ac, the potential between signs ac and ac is the same regardless of whether a detection object is present or not. Therefore, the signal (1) from the positive terminal of the power supply 304 is output to the first output wiring 313 via the power supply wiring 311, and a value of 1 is applied to the first load 307.

[0084] The exclusive OR circuit 303 receives a detection signal (0) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 1, which represents the result of the calculation. This signal z (1) is input to the base terminal of the second PNP transistor 306.

[0085] Since the signal z(1) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306, no current flows from the base terminal to the exclusive OR circuit 303, and no current flows between the emitter terminal and the collector terminal. In other words, the second PNP transistor 306 is in a non-conducting state. Therefore, the second load 308 is maintained in a state where 0 is applied.

[0086] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (0 applied), and since the states of both loads are reversed, it determines that there is no abnormality. In other words, when there is no object to detect, the detection unit 309 cannot determine that there is an abnormality even if the power supply wiring 311 and the first output wiring 313 are short-circuited between codes ac. However, the detection unit 309 can determine that there is an abnormality when there is a change in the detection state, that is, when the state changes from a state with no object to a state with an object to detect.

[0087] (8-b. If a detection sample is present) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0088] Here, since the power supply wiring 311 and the first output wiring 313 are short-circuited between the signs ac and ac, the potential between signs ac and ac is the same regardless of whether a detection object is present or not. Therefore, the signal (1) from the positive terminal of the power supply 304 is output to the first output wiring 313 via the power supply wiring 311, and a value of 1 is applied to the first load 307.

[0089] The exclusive OR circuit 303 receives a detection signal (1) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 0, which represents the result of the calculation. This signal z (0) is input to the base terminal of the second PNP transistor 306.

[0090] The signal z(0) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306. As a result, current flows from the base terminal to the exclusive OR circuit 303, and also between the emitter and collector terminals. In other words, the second PNP transistor 306 becomes conductive. Therefore, the second output wire 314 outputs 1 as the second output signal, and the second output signal (1) is applied to the second load 308.

[0091] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (1 applied), and since the states of both loads are the same, it determines that there is an abnormality.

[0092] (9. If there is no internal abnormality in sensor 1 and the power supply wiring 311 and the second output wiring 314 are short-circuited) For example, assume that the power supply wiring 311 and the second output wiring 314 are short-circuited between symbols ad and ad.

[0093] (9-a. If a substance is detected) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0094] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0095] Since the detection signal (1) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, no current flows from the base terminal to the first output circuit 301, and no current flows between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 is in a non-conducting state. Therefore, the first load 307 is maintained in a state where 0 is applied.

[0096] On the other hand, since the power supply wiring 311 and the second output wiring 314 are short-circuited between the symbols ad and ad, the potential between the symbols ad and ad is the same regardless of whether or not a detection object is present. Therefore, the signal (1) from the positive terminal of the power supply 304 is output to the second output wiring 314 via the power supply wiring 311, and a value of 1 is applied to the second load 308.

[0097] The detection unit 309 acquires the state of the first load 307 (0 is applied) and the state of the second load 308 (1 is applied). The detection unit 309 determines that there is no abnormality because the states of both loads are inversely related. In other words, when a detection object is present, the detection unit 309 cannot determine that there is an abnormality even if the power supply wiring 311 and the second output wiring 314 are short-circuited between symbols ad and a. However, the detection unit 309 can determine that there is an abnormality when there is a change in the detection state, that is, when the state changes from when a detection object is present to when there is no detection object.

[0098] (9-b. If no detectable organism is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0099] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0100] The detection signal (0) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, causing current to flow from the base terminal towards the first output circuit 301, and also between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 becomes conductive. Therefore, the first output wire 313 outputs 1 as the first output signal, and the first output signal (1) is applied to the first load 307.

[0101] On the other hand, since the power supply wiring 311 and the second output wiring 314 are short-circuited between the symbols ad and ad, the potential between the symbols ad and ad is the same regardless of whether or not a detection object is present. Therefore, the signal (1) from the positive terminal of the power supply 304 is output to the second output wiring 314 via the power supply wiring 311, and a value of 1 is applied to the second load 308.

[0102] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (1 applied), and since the states of both loads are the same, it determines that there is an abnormality.

[0103] (10. If there is no internal abnormality in sensor 1 and the first output wiring 313 and the second output wiring 314 are short-circuited) For example, assume that the first output wiring 313 and the second output wiring 314 are short-circuited between the symbols cd.

[0104] (10-a. If a detection sample is present) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0105] The exclusive OR circuit 303 receives a detection signal (1) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 0, which represents the result of the calculation. This signal z (0) is input to the base terminal of the second PNP transistor 306.

[0106] The signal z(0) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306. As a result, current flows from the base terminal to the exclusive OR circuit 303, and also between the emitter and collector terminals. In other words, the second PNP transistor 306 becomes conductive. Therefore, the second output wire 314 outputs 1 as the second output signal, and the second output signal (1) is applied to the second load 308.

[0107] Here, since the first output wiring 313 and the second output wiring 314 are short-circuited between the signs cd, the potential between signs cd is the same. Therefore, the second output signal (1) is output from the second output wiring 314 to the first output wiring 313 regardless of whether a detection object is present or not. As a result, the second output signal (1) is applied to the first load 307.

[0108] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (1 applied). Since the states of both loads are the same, the detection unit 309 determines that there is an abnormality.

[0109] (10-b. If no detectable organism is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0110] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0111] The detection signal (0) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, causing current to flow from the base terminal towards the first output circuit 301, and also between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 becomes conductive. Therefore, the first output wire 313 outputs 1 as the first output signal, and the first output signal (1) is applied to the first load 307.

[0112] Here, since the first output wiring 313 and the second output wiring 314 are short-circuited between the signs cd, the potential between signs cd is the same. Therefore, the first output signal (1) is output from the first output wiring 313 to the second output wiring 314 regardless of whether a detection object is present or not. As a result, the first output signal (1) is applied to the second load 308.

[0113] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (1 applied). Since the states of both loads are the same, the detection unit 309 determines that there is an abnormality.

[0114] (11. If there is no internal abnormality in sensor 1 and the first output wiring 313 and the ground wiring 312 are short-circuited) For example, assume that the first output wiring 313 and the ground wiring 312 are short-circuited between the signs cb.

[0115] (11-a. If a detection sample is present) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0116] Here, since the first output wiring 313 and the ground wiring 312 are short-circuited between the signs cb, the potential between signs cb is the same regardless of whether a detection object is present or not. As a result, the first load 307 is maintained in a state where 0 is applied.

[0117] The exclusive OR circuit 303 receives a detection signal (1) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 0, which represents the result of the calculation. This signal z (0) is input to the base terminal of the second PNP transistor 306.

[0118] The signal z(0) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306. As a result, current flows from the base terminal to the exclusive OR circuit 303, and also between the emitter and collector terminals. In other words, the second PNP transistor 306 becomes conductive. Therefore, the second output wire 314 outputs 1 as the second output signal, and the second output signal (1) is applied to the second load 308.

[0119] The detection unit 309 acquires the state of the first load 307 (0 applied) and the state of the second load 308 (1 applied). The detection unit 309 determines that there is no abnormality because the states of both loads are inversely related. In other words, when a detection object is present, the detection unit 309 cannot determine that there is an abnormality even if the first output wiring 313 and the ground wiring 312 are short-circuited between the symbols cb. However, the detection unit 309 can determine that there is an abnormality when there is a change in the detection state, that is, when the state changes from when a detection object is present to when there is no detection object.

[0120] (11-b. If no detection is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0121] Here, since the first output wiring 313 and the ground wiring 312 are short-circuited between the signs cb, the potential between signs cb is the same regardless of whether a detection object is present or not. As a result, the first load 307 is maintained in a state where 0 is applied.

[0122] The exclusive OR circuit 303 receives a detection signal (0) from the first input terminal A and an abnormality detection signal (1) from the second input terminal B. The exclusive OR circuit 303 calculates the exclusive OR of these signals and outputs a signal z of 1, which represents the result of the calculation. This signal z (1) is input to the base terminal of the second PNP transistor 306.

[0123] Since the signal z(1) output from the exclusive OR circuit 303 is input to the base terminal of the second PNP transistor 306, no current flows from the base terminal to the exclusive OR circuit 303, and no current flows between the emitter terminal and the collector terminal. In other words, the second PNP transistor 306 is in a non-conducting state. Therefore, the second load 308 is maintained in a state where 0 is applied.

[0124] The detection unit 309 acquires the state of the first load 307 (0 is applied) and the state of the second load 308 (0 is applied), and since the states of both loads are the same, it determines that there is an abnormality.

[0125] (12. If there is no internal abnormality in sensor 1 and the second output wiring 314 and the ground wiring 312 are short-circuited) For example, assume that the second output wire 314 and the ground wire 312 are short-circuited between the sign dB values.

[0126] (12-a. If no detection is found) If no object is detected, the object detection unit 2 outputs 0 (Low) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0127] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0128] The detection signal (0) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, causing current to flow from the base terminal towards the first output circuit 301, and also between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 becomes conductive. Therefore, the first output wire 313 outputs 1 as the first output signal, and the first output signal (1) is applied to the first load 307.

[0129] On the other hand, since the second output wiring 314 and the ground wiring 312 are short-circuited between the sign dB values, the potential between the sign dB values ​​is the same regardless of whether a detection object is present or not. As a result, the second load 308 is maintained in a state where 0 is applied.

[0130] The detection unit 309 acquires the state of the first load 307 (1 applied) and the state of the second load 308 (0 applied). Since the states of the two loads are different, the detection unit 309 determines that there is no abnormality. In other words, when there is no object to detect, the detection unit 309 cannot determine that there is an abnormality even if the second output wiring 314 and the ground wiring 312 are short-circuited between the codes dB. However, the detection unit 309 can determine that there is an abnormality when there is a change in the detection state, that is, when the state changes from a state with no object to a state with an object to detect.

[0131] (12-b. If a detection sample is present) If an object is detected, the object detection unit 2 outputs 1 (High) as a detection signal. The object detection unit 2 also outputs 1 (High) as an anomaly detection signal.

[0132] The first output circuit 301 acquires a detection signal from the object detection unit 2 and outputs the acquired detection signal from its output terminal. This detection signal is input to the base terminal of the first PNP transistor 305 and to the first input terminal A of the exclusive OR circuit 303.

[0133] Since the detection signal (1) output from the first output circuit 301 is input to the base terminal of the first PNP transistor 305, no current flows from the base terminal to the first output circuit 301, and no current flows between the emitter terminal and the collector terminal. In other words, the first PNP transistor 305 is in a non-conducting state. Therefore, the first load 307 is maintained in a state where 0 is applied.

[0134] On the other hand, since the second output wiring 314 and the ground wiring 312 are short-circuited between the sign dB values, the potential between the sign dB values ​​is the same regardless of whether a detection object is present or not. As a result, the second load 308 is maintained in a state where 0 is applied.

[0135] The detection unit 309 acquires the state of the first load 307 (0 is applied) and the state of the second load 308 (0 is applied), and since the states of both loads are the same, it determines that there is an abnormality.

[0136] As described above, the abnormality detection device 3 can detect wiring abnormalities (open circuit or short circuit) and internal abnormalities of the sensor 1 based on the states of the first load 307 and the second load 308. If a wiring abnormality (open circuit or short circuit) and an internal abnormality occur simultaneously, it is expected that a state indicating a wiring abnormality will appear in both the first and second loads. Therefore, even if a wiring abnormality and an internal abnormality occur simultaneously, the detection unit 309 can detect the abnormality based on the states of the first and second loads.

[0137] Note that the same relationship holds even if the logic shown in Figure 2 is reversed. In this case, simply replace signal (1) with signal (0) and signal (0) with signal (1) in Figure 2.

[0138] Furthermore, although the above description explains an example in which both the first switching element 305 and the second switching element 306 are composed of PNP transistors, the first switching element 305 and the second switching element 306 are not limited to this and may be composed of, for example, P-channel type field-effect transistors.

[0139] Furthermore, the first switching element 305 and the second switching element 306 may be composed of an NPN transistor or an N-channel field-effect transistor. If the first switching element 305 and the second switching element 306 are composed of an NPN transistor or an N-channel field-effect transistor, the abnormality detection device 3 only needs to have the arrangement of the power supply wiring 311, to which the positive terminal of the power supply 304 is connected, and the ground wiring 312, to which the negative terminal of the power supply 304 is connected, reversed in the configuration shown in Figure 1.

[0140] In this case, the first switching element 305 has one end connected to the ground wire 312 and the other end connected to one end of the first output wire 313, and switches its conduction state in accordance with the detection signal output by the first output circuit 301. The second switching element 306 has one end connected to the ground wire 312 and the other end connected to one end of the second output wire 314, and switches its conduction state in accordance with the signal output by the exclusive OR circuit 303. The first load 307 has one end connected to the other end of the first output wire 313 and the other end connected to the power supply wire 311. The second load 308 has one end connected to the other end of the second output wire 314 and the other end connected to the power supply wire 311.

[0141] Even with this configuration, the abnormality detection device 3 operates in the same way as when the first switching element 305 and the second switching element 306 are composed of PNP transistors, and can detect wiring abnormalities (open circuit or short circuit) and internal abnormalities of the sensor 1 based on the state of the first load 307 and the second load 308.

[0142] As described above, according to Embodiment 1, the abnormality detection device 3 includes a first output circuit 301 that outputs a detection signal indicating the presence or absence of a detected object obtained by the sensor 1, a second output circuit 302 that outputs an abnormality detection signal indicating the presence or absence of an internal abnormality in the sensor 1, an exclusive OR circuit 303 that outputs a signal indicating the result of calculating the exclusive OR of the detection signal output by the first output circuit 301 and the abnormality detection signal output by the second output circuit 302, a power supply 304 whose positive terminal is connected to the power supply wiring 311 and whose negative terminal is connected to the ground wiring 312, and a first circuit whose one end is connected to the power supply wiring 311 and the other end is connected to one end of the first output wiring 313, and which switches the conduction state according to the detection signal output by the first output circuit 301. The abnormality detection device 3 comprises a switching element 305, a second switching element 306 having one end connected to the power supply wiring 311 and the other end connected to one end of the second output wiring 314, which switches its conduction state according to the signal output by the exclusive OR circuit 303, a first load 307 having one end connected to the other end of the first output wiring 313 and the other end connected to the ground wiring 312, a second load 308 having one end connected to the other end of the second output wiring 314 and the other end connected to the ground wiring 312, and a detection unit 309 that detects at least one of abnormalities in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312, as well as an internal abnormality of the sensor 1, based on the state of the first load 307 and the state of the second load 308. As a result, the abnormality detection device 3 can detect wiring abnormalities and internal abnormalities of the sensor 1 without adding any load compared to the conventional configuration.

[0143] Furthermore, the abnormality detection device 3 includes a first output circuit 301 that outputs a detection signal indicating the presence or absence of a detected object obtained by the sensor 1, a second output circuit 302 that outputs an abnormality detection signal indicating the presence or absence of an internal abnormality in the sensor 1, an exclusive OR circuit 303 that outputs a signal indicating the result of calculating the exclusive OR of the detection signal output by the first output circuit 301 and the abnormality detection signal output by the second output circuit 302, a power supply 304 whose positive terminal is connected to the power supply wiring 311 and whose negative terminal is connected to the ground wiring 312, and a first switch whose one end is connected to the ground wiring 312 and the other end is connected to one end of the first output wiring 313, and which switches the conduction state according to the detection signal output by the first output circuit 301. The abnormality detection device 3 comprises a 305 element, a second switching element 306 with one end connected to the ground wiring 312 and the other end connected to one end of the second output wiring 314, which switches its conduction state according to the signal output by the exclusive OR circuit 303, a first load 307 with one end connected to the other end of the first output wiring 313 and the other end connected to the power supply wiring 311, a second load 308 with one end connected to the other end of the second output wiring 314 and the other end connected to the power supply wiring 311, and a detection unit 309 that detects at least one of abnormalities in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312, as well as an internal abnormality of the sensor 1, based on the state of the first load 307 and the state of the second load 308.

[0144] Furthermore, the detection unit 309 detects at least one of the following when the state of the first load 307 and the state of the second load 308 are the same: an abnormality in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312, as well as an internal abnormality in the sensor 1. As a result, the abnormality detection device 3 can accurately detect abnormalities based on the states of the first load 307 and the second load 308.

[0145] Furthermore, the detection unit 309 detects abnormalities in the power supply wiring 311, the first output wiring 313, the second output wiring 314, and the ground wiring 312 when the state of the first load 307 and the state of the second load 308 change from an inverted state to the same state, in response to the detection signal and the abnormality detection signal. As a result, the abnormality detection device 3 can accurately detect wiring abnormalities based on the state changes of the first load 307 and the second load 308.

[0146] Furthermore, within the scope of the present invention, any component of the embodiment can be modified, or any component can be omitted in the embodiment. [Explanation of symbols]

[0147] 1 sensor 2. Detector Unit 3. Anomaly detection device 301 First output circuit 302 Second output circuit 303 Exclusive OR circuit 304 Power supply 305 First switching element (first PNP transistor) 306 Second switching element (second PNP transistor) 307 First load 308 Second load 309 Detection unit 311 Power wiring 312 Ground wiring 312 Ground wiring 313 First output wiring 314 Second output wiring A First input terminal of the exclusive OR circuit B Second input terminal of the exclusive OR circuit Z is the output terminal of the exclusive OR circuit.

Claims

1. a first output circuit that outputs a detection signal indicating the presence or absence of a detected object obtained by the sensor; a second output circuit that outputs an abnormality detection signal indicating whether or not there is an internal abnormality in the sensor; an exclusive OR circuit that outputs a signal indicating a result of an exclusive OR operation on the detection signal output by the first output circuit and the abnormality detection signal output by the second output circuit; a power supply whose positive terminal is connected to the power supply wiring and whose negative terminal is connected to the ground wiring; a first switching element having one end connected to the power supply wiring and the other end connected to one end of a first output wiring, and switching a conduction state in response to a detection signal output by the first output circuit; a second switching element having one end connected to the power supply wiring and the other end connected to one end of a second output wiring, and switching a conduction state in response to a signal output from the exclusive OR circuit; a first load having one end connected to the other end of the first output wiring and the other end connected to the ground wiring; a second load having one end connected to the other end of the second output wiring and the other end connected to the ground wiring; a detection unit that detects at least one of an abnormality in the power supply wiring, the first output wiring, the second output wiring, and the ground wiring, and an internal abnormality of the sensor, based on a state of the first load and a state of the second load; An anomaly detection device equipped with the

2. a first output circuit that outputs a detection signal indicating the presence or absence of a detected object obtained by the sensor; a second output circuit that outputs an abnormality detection signal indicating whether or not there is an internal abnormality in the sensor; an exclusive OR circuit that outputs a signal indicating a result of an exclusive OR operation on the detection signal output by the first output circuit and the abnormality detection signal output by the second output circuit; a power supply whose positive terminal is connected to the power supply wiring and whose negative terminal is connected to the ground wiring; a first switching element having one end connected to the ground wiring and the other end connected to one end of a first output wiring, and switching a conduction state in response to a detection signal output by the first output circuit; a second switching element having one end connected to the ground wiring and the other end connected to one end of a second output wiring, and switching a conductive state in response to a signal output from the exclusive OR circuit; a first load having one end connected to the other end of the first output wiring and the other end connected to the power supply wiring; a second load having one end connected to the other end of the second output wiring and the other end connected to the power supply wiring; a detection unit that detects at least one of an abnormality in the power supply wiring, the first output wiring, the second output wiring, and the ground wiring, and an internal abnormality of the sensor, based on a state of the first load and a state of the second load; An anomaly detection device equipped with the

3. The detection unit 3. The abnormality detection device according to claim 1, wherein when the state of the first load and the state of the second load are the same, the device detects at least one of an abnormality in the power supply wiring, the first output wiring, the second output wiring, and the ground wiring, and an internal abnormality in the sensor.

4. The detection unit 4. The abnormality detection device according to claim 1, wherein an abnormality in the power supply wiring, the first output wiring, the second output wiring, and the ground wiring is detected when the state of the first load and the state of the second load change from mutually inverted states to the same state in response to the detection signal and the abnormality detection signal.

5. A sensor, A sensor system comprising the anomaly detection device according to any one of claims 1 to 4.

Images