Safety switch and switching system

Abstract

A safety switch capable of improving display accuracy of presence or absence of an anomaly in consideration of detection of presence or absence of an anomaly by other safety switches is provided. A safety switch (200) includes a detection unit configured to detect presence or absence of an anomaly, an output unit configured to output an anomaly detection signal indicating a detection result of presence or absence of an anomaly, an input unit configured to input a display control signal, and a display unit configured to perform display based on the display control signal.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a safety switch and a switch system. BACKGROUND

[0002] In the related art, a safety switch is known that is attached to a front door of a machine tool or a machine tool, a door portion surrounding a safety fence of an industrial robot, or the like, and detects opening and closing of the door. In such a safety switch, a dedicated actuator attached to the door (movable side) is inserted into a safety switch main body by closing the door, and contacts in the main body are switched to transmit a signal. As one of safety switches, a safety switch including a housing that includes wireless circuitry and a plurality of display lamps, the wireless circuitry supplies power to a wireless tag provided in an actuator and receives a signal transmitted from the wireless tag (see Patent Literature 1). The safety switch turns on and off a large display lamp according to an open and closed state of the actuator, and turns on and off a small display lamp according to an output signal switching device (OSSD) signal or the like.

[0003] Related Art Documents

[0004] Patent Literature

[0005] Patent Literature 1: JP-A-2019-139877 SUMMARY

[0006] Technical Problem to be Solved by the Invention

[0007] The safety switch in the related art has room for improvement in terms of display of presence or absence of an anomaly detected by the safety switch.

[0008] The present disclosure provides a safety switch and a switch system that can improve display precision of presence or absence of an anomaly in consideration of presence or absence of an anomaly detected by another safety switch.

[0009] Technical Means for Solving the Problem

[0010] One aspect of the present disclosure is a safety switch including a detection unit configured to detect presence or absence of an anomaly, an output unit configured to output an anomaly detection signal indicating a detection result of presence or absence of the anomaly, an input unit configured to input a display control signal, and a display unit configured to perform display based on the display control signal.

[0011] An aspect of the present disclosure is a switch system including a plurality of safety switches each of which is a safety switch, wherein the plurality of safety switches includes the plurality of safety switches including a first safety switch and a second safety switch, an output unit of the second safety switch outputs a detection result of presence or absence of an abnormality detected by a detection unit of the second safety switch to the first safety switch, and the first safety switch includes a control unit configured to output the display control signal to the second safety switch based on the detection result of presence or absence of an abnormality output by the second safety switch.

[0012] An aspect of the present disclosure is a switch system including a plurality of safety switches each of which includes a detection unit configured to detect presence or absence of an abnormality and an output unit configured to output an abnormality detection signal indicating a detection result of presence or absence of an abnormality, the plurality of safety switches being connected in series, the plurality of safety switches including a first safety switch disposed at a last stage and a second safety switch disposed at a position other than the last stage, the output unit of the first safety switch being configured to output the abnormality detection signal through a duplex signal line, and the output unit of the second safety switch being configured to output the abnormality detection signal through a single signal line.

[0013] Advantages of the present invention

[0014] According to the present disclosure, display accuracy of presence or absence of an abnormality can be improved in consideration of detection of presence or absence of an abnormality by other switches. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a diagram showing a configuration example of an apparatus equipped with a door.

[0016] Figure 2 is a perspective view showing a configuration example of a door.

[0017] Figure 3 is a block diagram showing a configuration example of a safety switch.

[0018] Figure 4 is a diagram showing an example of each of signal lines connected to an input / output unit of a safety switch.

[0019] Figure 5 is a diagram showing an example of a display pattern obtained by a single light source in a safety switch.

[0020] Figure 6is a diagram showing a first example of a connection relationship between a plurality of safety switches and a safety PLC.

[0021] Figure 7 is a diagram showing a second example of a connection relationship between a plurality of safety switches and a safety PLC.

[0022] Figure 8 is a diagram showing a third example of a connection relationship between a plurality of safety switches and a safety PLC.

[0023] Figure 9 is a diagram showing a first transmission device example of a display control signal corresponding to the third example of a connection relationship between a plurality of safety switches and a safety PLC.

[0024] Figure 10 is a diagram showing a second transmission device example of a display control signal corresponding to the third example of a connection relationship between a plurality of safety switches and a safety PLC.

[0025] Figure 11 is a diagram showing a first display example of a plurality of safety switches.

[0026] Figure 12 is a diagram showing a second display example of a plurality of safety switches.

[0027] Figure 13 is a diagram showing a display based on an abnormality detection signal in a plurality of safety switches in a comparative example.

[0028] Figure 14 is a diagram showing a display example based on a display control signal in a plurality of safety switches according to an embodiment.

[0029] Figure 15 is a diagram showing an output based on an abnormality detection signal in a plurality of safety switches in a comparative example.

[0030] Figure 16 is a diagram showing an output example based on an abnormality detection signal in a plurality of safety switches according to an embodiment. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments will be described in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed description can be omitted. For example, well-known matters or repetitive description of substantially the same configuration can be omitted. This avoids unnecessary redundancy in the following description and facilitates understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the scope of the subject matter described in the claims.

[0032] (IntRODUCTION OF CONTENTS OF EMBODIMENTS)

[0033] The safety switch of Patent Literature 1 can be cascaded with other safety switches. In the cascade, a plurality of safety switches are connected in series. Each of the safety switches receives a detection signal of a safety switch of a previous stage (upstream side) as an OSSD signal. The detection signal of the safety switch of the previous stage is a detection signal indicating that there is an abnormality when an abnormality is detected up to the previous stage in at least one of the safety switches, and is a detection signal indicating that there is no abnormality when no abnormality is detected up to the previous stage in all the safety switches. Therefore, the safety switch at the stage next to the safety switch having an abnormality can be identified, and it is shown that there is an abnormality in the other safety switches. In contrast, the safety switch in the stage previous to the safety switch having an abnormality cannot be identified, and it is shown that there is an abnormality in the other safety switches of the next stage. Therefore, in the safety switch of the related art, the display accuracy of the presence or absence of an abnormality in the other safety switches can be reduced.

[0034] Hereinafter, a safety switch and a switch system capable of improving the display accuracy of the presence or absence of an abnormality in consideration of the presence or absence of an abnormality detected by other safety switches are described.

[0035] (Embodiment)

[0036] Figure 1 is a diagram showing a configuration example of a door-equipped apparatus 10 according to an embodiment. The door-equipped apparatus 10 includes one or more doors 100 and one or more safety switches 200. The door 100 can broadly include those doors relating to doors such as openings and large doors, and can include windows. The door-equipped apparatus 10 (for example, a manufacturing apparatus and, for example, a manufacturing apparatus main body) is housed inside the door-equipped apparatus 10. In addition, a switch system 5 is formed by including a plurality of safety switches 200.

[0037] Figure 2 is a perspective view showing a configuration example of the door 100. Each door 100 includes a fixed frame 111, a movable frame 112, and a door main body 113.

[0038] The fixed frame 111 can be a part of a member covering the outer periphery of the door-equipped apparatus 10. The fixed frame 111 is, for example, an aluminum frame, and can be a frame composed of other materials. The fixed frame 111 does not have a translucent portion.

[0039] The movable frame 112 is movable with respect to the fixed frame 111. As a result, the door 100 can be opened and closed. The movable frame 112 is, for example, an aluminum frame, and can be a frame composed of other materials. The movable frame 112 does not have a translucent portion.

[0040] In the door body 113, a periphery of the door body 113 is surrounded by the movable frame 112. The door body 113 is constituted of, for example, a light-transmissive member. The light-transmissive member can be constituted of, for example, a transparent plastic or a glass, and the following description of the light-transmissive member is equally applicable.

[0041] It should be noted that the method of opening and closing the door 100 can include a hinged door method, a sliding door method, a folding door method, a bellows method, a double door method, a gull wing method, and the like.

[0042] The safety switch 200 functions as a door sensor that detects opening and closing of the door 100. The safety switch 200 can detect opening and closing of the door 100 to which the safety switch 200 is attached (the own door), and can also detect opening and closing of the door 100 other than the door to which the safety switch 200 is attached (the other door). The safety switch 200 can have an interlock function, an external device monitoring (EDM) function, and the like.

[0043] The safety switch 200 includes a sensor body 210 and an actuator 250. The sensor body 210 is disposed on the fixed frame 111, inside the door-equipped device 10. The actuator 250 is disposed on the movable frame 112, inside the door-equipped device 10. Thus, when viewed from a confirmer who confirms from the outside of the door-equipped device 10, the safety switch 200 is located at the rear surface side of the fixed frame 111 and the movable frame 112. The confirmer can confirm the display of the safety switch 200 through the door body 113 (as a light-transmissive member).

[0044] A plurality of safety switches 200 can be connected to each other by any connection method. For example, a plurality of safety switches 200 can be connected in series and in cascade. In this case, the stages (positions) of the series connection can be described hierarchically. For example, the first safety switch 200 of the series connection can be a safety switch 200 of the first stage, and the last safety switch 200 of the series connection can be a safety switch 200 of the last stage. The safety switch 200 of the last stage is connected to a safety programmable logic controller (PLC).

[0045] Figure 3 is a block diagram showing a configuration example of the safety switch 200. The safety switch 200 includes a sensor body 210 and an actuator 250. The sensor body 210 includes a processor 211, a coil 212, a light source 213, and an input / output unit 219. The actuator 250 includes a radio frequency identification (RFID) tag 280.

[0046] The processor 211 cooperates with the memory included in the sensor main body 210 to perform various functions. The processor 211 can include a microprocessor (MPU) / central processing unit (CPU) / digital processor (DSP), etc. The processor 211 controls the overall operation of the sensor main body 210.

[0047] The processor 211 detects whether the door of the self is closed (closed state) or opened (opened state) based on the state in which the coil 212 of the sensor main body 210 and the RFID tag 280 of the actuator 250 approach each other. Details of the detection of the opened state and the closed state of the door of the self will be described later.

[0048] The coil 212 receives power from the outside via the input / output unit 219 and transmits the power to an external device (for example, the actuator 250) through a wireless power transmission device. The wireless power transmission device can be an electromagnetic induction system or a magnetic field resonance system. Upon receiving a predetermined signal from the external device, the coil 212 informs the processor 211 that the predetermined signal is received. The external device is, for example, the actuator 250, and more specifically, the RFID tag 280 of the actuator 250. The coil 212 detects the closed state (an example in which there is no abnormality) by receiving the predetermined signal from the actuator 250, and detects the opened state (an example in which there is an abnormality) by not receiving the predetermined signal.

[0049] The number of the light source 213 can be one or more. The light source 213 emits (displays) light under the control of the processor 211. The light source 213 can display based on the detection result of the presence or absence of an abnormality of the door 100 (the door of the self) obtained through the safety switch 200 (the switch of the self). The light source 213 can perform display based on the detection result of the presence or absence of an abnormality of another door 100 (another door) obtained through another safety switch 200 (another switch) different from the safety switch 200. The presence or absence of an abnormality of the door 100 can include the opened state and the closed state of the door 100. The detection result of the presence or absence of an abnormality detected by the safety switch 200 is also simply referred to as "detection result". The light source 213 can display in various display modes based on at least one of the detection result obtained through the switch of the self and the detection result obtained through the switch of the self. The display mode can be a display color, a display pattern (for example, light emission, flickering, and extinction), light intensity, etc.

[0050] The light source 213 can project light to the actuator 250 through a light projection port of the sensor body 210 facing the actuator 250. The actuator 250 can receive the projected light, guide the light from the sensor body 210 through the light-transmissive member, and emit (output) visible light. In addition, the light source 213 can directly emit (output) light outside the safety switch 200 without projecting light to the actuator 250. In any case, it is enough to confirm the light emitted by the safety switch 200 from the outside of the device 10 equipped with the door through the door body 113 composed of the light-transmissive member.

[0051] The input / output unit 219 performs input and output of data, information, and signals with an external device (e.g., another switch or a safety PLC). Various signal lines are connected to the input / output unit 219. The input / output unit 219 inputs and outputs (at least one of input and output) signals such as a power signal, an abnormality detection signal, and a display control signal via the signal lines. The input / output unit 219 can include various signal lines.

[0052] The power signal includes power or electricity supplied to various electrical components included in the safety switch 200. The abnormality detection signal indicates a detection result of presence or absence of an abnormality in another switch connected to a previous stage of the own switch. The abnormality detection signal indicates, for example, a detection result of an open state and a closed state of another door on which another switch connected to a previous stage of the own switch is provided. The display control signal is a signal for controlling display by the light source 213. The display control signal is based on a detection result of presence or absence of an abnormality obtained through other switches in a previous stage, the own switch, and other switches in a subsequent stage. The display control signal is determined based on, for example, a detection result of an open state and a closed state of each of the doors 100 on which each of the safety switches 200 in the safety switch 200 is provided.

[0053] The RFID tag 280 is arranged in a range in which the RFID tag 280 can communicate with the coil 212 of the sensor body 210 when the door 100 is in a closed state. The RFID tag 280 is provided on, for example, a facing surface side facing the sensor body 210 when the door 100 is in a closed state. The RFID tag 280 transmits a predetermined signal. The RFID tag 280 is, for example, a passive tag and operates by receiving a power supply from the outside (e.g., the sensor body 210). For example, the RFID tag 280 receives a power supply from the sensor body 210 via the coil 212 and transmits a predetermined signal to the sensor body 210. It should be noted that the predetermined signal can include at least information for identifying the RFID tag 280.

[0054] Here, a specific method for detecting the opening and closing of the door 100 will be described.

[0055] When the actuator 250 is disposed at a predetermined position with respect to the sensor body 210, the sensor body 210 detects the actuator 250. Specifically, when the RFID tag 280 of the actuator 250 is located within a range in which wireless power transmission from the coil 212 of the sensor body 210 is possible, the sensor body 210 supplies power to the actuator 250, and the actuator 250 transmits a predetermined signal to the sensor body 210. When it is detected that the coil 212 receives the predetermined signal from the actuator 250, the coil 212 detects the actuator 250 and informs the processor 211. When this notification is received, the processor 211 identifies the actuator 250.

[0056] When the sensor body 210 detects the actuator 250, the processor 211 determines that the movable frame 112 on which the actuator 250 is disposed faces the fixed frame 111 on which the sensor body 210 in a predetermined state is disposed, and that the door 100 is in a closed state. When the sensor body 210 does not detect the actuator 250, it is determined that the movable frame 112 on which the actuator 250 is disposed does not face the fixed frame 111 on which the sensor body 210 in a predetermined state is disposed, and that the door 100 is in an open state.

[0057] Next, a manufacturing apparatus will be described.

[0058] The manufacturing apparatus that is the door-equipped apparatus 10 is an apparatus that manufactures various products (for example, electrical, mechanical, and chemical substances). The manufacturing apparatus or product is not limited, and is, for example, a manufacturing apparatus or product that will be considered processing. The manufacturing apparatus can be operated according to the state of the safety switch 200. For example, when the closed state of all the doors 100 is detected by the safety switch 200, the manufacturing apparatus can be operable, and when the open state of at least one door 100 is detected by the safety switch 200, the manufacturing apparatus can be inoperable. Thus, the door-equipped apparatus 10 can maintain the manufacturing apparatus or product in a safe state.

[0059] The operation of the manufacturing apparatus can be allowed or prohibited according to the state of the safety switch 200 by a safety PLC. The safety PLC is connected between the safety switch 200 and the manufacturing apparatus main body. The safety PLC can acquire an abnormality detection signal from at least one of the safety switches 200 and give the abnormality detection signal to determine to allow or prohibit the operation of the manufacturing apparatus. For example, when the closed state of all the doors 100 is detected by the safety switch 200, the processor of the safety PLC can allow the operation of the manufacturing apparatus, and when the open state of at least one of the doors 100 is detected by the safety switch 200, the operation of the manufacturing apparatus can be prohibited.

[0060] Although not particularly shown, the safety PLC includes a processor, an input / output unit, and the like. The processor cooperates with a memory included in the safety PLC to implement various functions. The processor can include an MPU, a CPU, a DSP, and the like. The processor controls the overall operation of the safety PLC. The input / output unit performs input and output of data, information, and signals with external devices (for example, the safety switch 200 or the manufacturing apparatus). Various signal lines are connected to the input / output unit. The input / output unit (at least one of input and output) inputs and outputs signals such as a power supply signal, an abnormality detection signal, a display control signal, and a control signal for controlling the manufacturing apparatus via the signal lines. It should be noted that the safety PLC can be included in the switch system 5.

[0061] It should be noted that, in Figure 1 , a plurality of doors 100 are provided to surround the manufacturing apparatus, the door-equipped apparatus 10 is formed in a rectangular shape in a plan view, and the present disclosure is not limited thereto. For example, a plurality of doors 100 can be arranged in one direction. In this case, the plurality of doors 100 can be linearly arranged in a direction parallel to the surface of the door main body 113, or can be linearly arranged in a direction perpendicular to the surface of the door 100. When the doors 100 are arranged perpendicular to the surface of the door 100, it is assumed that a large number of doors 100 are arranged in the depth direction when viewed from the confirmers, and it can be difficult to confirm the display of the safety switch 200 arranged on the back side.

[0062] Next, the classification of the safety switch 200 will be described.

[0063] A plurality of safety switches 200 are provided and classified into a master switch 200M and a slave switch 200S. The master switch 200M is provided at the last stage among the plurality of safety switches 200, and is provided immediately before the safety PLC 400. The slave switch 200S is a safety switch other than the master switch 200M among the plurality of safety switches 200, and is a safety switch adjacent to another safety switch 200 rather than adjacent to the safety PLC.

[0064] Figure 4 is a diagram showing an example of each of the signal lines connected to the input / output unit 219 of the safety switch 200. Figure 4 An example in which the master switch 200M and the slave switch 200S are connected to each other is shown.

[0065] A power supply signal line (+V and 0V), an OSSD signal line (OSSD1 and OSSD2), an inspection signal line (CHECK_IN and CHECK_OUT), and the like are connected to the input / output unit 219 of the master switch 200M. The power supply signal line transmits a power supply signal. The OSSD signal line transmits an abnormality detection signal from the master switch 200M to the safety PLC 400. OSSD1 and OSSD2 transmit the same signal. That is, the OSSD signal line is duplicated. The inspection signal line transmits at least one of an abnormality detection signal and a display control signal from the slave switch 200S and transmits at least one of the abnormality detection signal and the display control signal to the slave switch 200S. CHECK_IN is an input signal line, and CHECK_OUT is an output signal line.

[0066] A power supply signal line (+V and 0V), an inspection signal line (CHECK_IN and CHECK_OUT), and the like are connected to the input / output unit 219 of the slave switch 200S. The power supply signal line transmits a power supply signal. The inspection signal line transmits at least one of an abnormality detection signal and a display control signal to another slave switch 200S or the master switch 200M. CHECK_IN is an input signal line, and CHECK_OUT is an output signal line.

[0067] As described above, the master switch 200M and the slave switch 200S differ in the number of signal lines through which an abnormality detection signal is transmitted. Specifically, the master switch 200M outputs an abnormality detection signal through duplicated signal lines (OSSD1 and OSSD2). The slave switch 200S outputs an abnormality detection signal via a single signal line (CHECK_OUT).

[0068] It should be noted that the main circuit of the master switch 200M and the main circuit of the slave switch 200S include, for example, the processor 211. A display control signal and an abnormality detection signal can be transmitted through physically different signal lines. That is, a plurality of inspection signal lines can be provided for each of the input and the output. In addition, the color of each of the signal lines is not limited to Figure 4 An example.

[0069] Next, the generation of a display control signal will be described.

[0070] The master switch 200M acquires the detection result of another switch (slave switch) by acquiring the abnormality detection signal. The processor 211 of the master switch 200M also acquires the detection result of its own switch. The processor 211 of the master switch 200M generates a display control signal based on the detection result of another switch and the detection result of its own switch. In this case, when the detection result of another switch and the detection result of its own switch all indicate the closed state, the processor 211 generates a display control signal including the closed information. In addition, when at least one of the detection result of another switch and the detection result of its own switch indicates the open state, the processor 211 generates a display control signal including the open information. The input / output unit 219 of the master switch 200M outputs the generated display control signal directly or indirectly to each of the slave switches 200S.

[0071] Instead of the master switch 200M, the safety PLC can generate a display control signal. In this case, the processor of the safety PLC outputs the generated display control signal directly or indirectly to each of the safety switches 200 through the input / output unit of the safety PLC.

[0072] Next, a display example based on the display control signal of the safety switch 200 will be described.

[0073] The input / output unit 219 of each of the slave switches 200S receives the display control signal from the master switch 200M. Alternatively, the input / output unit 219 of each of the safety switches 200 (master switch 200M and slave switch 200S) receives the display control signal from the safety PLC.

[0074] The light source 213 can display based on at least one of the display control signal and the detection result of its own switch. In this case, the display mode of the light source 213 can differ depending on the number of light sources 213 in the display based on at least one of the display control signal and the detection result of its own switch.

[0075] First, a case in which a plurality of light sources 213 is provided will be described. Here, it is exemplified that the light source 213 includes two light sources, a first light source 213A and a second light source 213B.

[0076] The light source 213 can respectively perform the display based on the detection result of its own switch and the display based on the display control signal. For example, the first light source 213A performs the display based on the detection result of its own switch, and the second light source 213B performs the display based on the display control signal.

[0077] When the detection result of the own switch indicates the closed state of the own door, the first light source 213A can display in the display mode DM1 (e.g., green light emission). Also, when the detection result of the own switch indicates the open state of the own door, the first light source 213A can display in the display mode DM2 (e.g., red light emission).

[0078] When the display control signal includes the closed information, the second light source 213B can perform display in the display mode DM1 (e.g., green light emission). Also, when the display control signal includes the open information, the second light source 213B can display in the display mode DM2 (e.g., red light emission).

[0079] First, a case in which one light source 213 is provided will be described.

[0080] The light source 213 simultaneously performs display based on the detection result of the own switch and display based on the display control signal. Therefore, it is preferable that the light source 213 perform display with more variation in display mode compared to a case in which a plurality of light sources 213 are present.

[0081] Figure 5 is a diagram illustrating an example of a display mode obtained by a single light source 213. In the display mode obtained by the single light source 213, either of the two tables T1 and T2 illustrated in Figure 5 may be applied.

[0082] For example, when the display control signal includes the closed information and the own switch detects the closed state, the light source 213 can display in the display mode DM1 (e.g., green light emission). When the own switch is in the open state, the display control signal is the open information. Therefore, there is no pattern in which the display control signal includes the closed information and the own switch detects the open state.

[0083] When the display control signal includes the open information, the light source 213 can display light in the display mode DM3 (e.g., yellow light emission) regardless of whether the own switch detects the closed state or the open state. Alternatively, when the display control signal includes the open information, the light source 213 can display in the display mode DM4 (e.g., green color blinking) when the own switch detects the closed state, and can display in the display mode DM2 (e.g., red light emission) when the own switch detects the open state.

[0084] When the display control signal includes the opening information, the safety switch 200 displays the light in the display mode DM3, whereby the recognizer of the display of the display mode DM3 can recognize that any of the safety switches detects the opening state, although the opening state and the closing state of the own door are unknown, and can take measures such as closing the other door. It should be noted that the opening state and the closing state of the own door can be directly recognized.

[0085] When the display control signal includes the opening information, the safety switch 200 displays the light in the display mode DM4, whereby the recognizer of the display of the display mode DM4 can recognize that the own door is in the closing state and any of the safety switches detects the opening state, and can take measures such as closing the other door.

[0086] When the display control signal includes the opening information, the safety switch 200 displays the light in the display mode DM2, whereby the recognizer of the display of the display mode DM2 can recognize that the own switch detects the opening state, although the opening state and the closing state of the other door are unknown. In the case of the display mode DM2, the recognizer can recognize whether the other door is also open by recognizing the display mode of the own switch after closing the own door.

[0087] Next, the connection relationship between the plurality of safety switches 200 and the safety PLC 400 will be described.

[0088] Figure 6 is a diagram showing a first example of the connection relationship between the plurality of safety switches 200 and the safety PLC 400. Figure 7 is a diagram showing a second example of the connection relationship between the plurality of safety switches 200 and the safety PLC 400. Figure 8 is a diagram showing a third example of the connection relationship between the plurality of safety switches 200 and the safety PLC 400.

[0089] In Figure 6 , each of the safety switches 200 is connected to the safety PLC 400. In the case of Figure 6 , the display control signal is generated by the safety PLC 400. Since each of the safety switches 200 is positioned immediately before the safety PLC 400, the safety switch 200 is the master switch 200M.

[0090] In Figure 6In the embodiment, the input / output unit 219 of each of the safety switches 200 outputs the abnormality detection signal of the safety PLC 400. The input / output unit of the safety PLC 400 acquires the abnormality detection signal from each of the safety switches 200. The processor of the safety PLC 400 generates the display control signal based on the abnormality detection signal from each of the safety switches 200. The input / output unit of the safety PLC 400 outputs the display control signal to each of the safety switches 200. The input / output unit 219 of each of the safety switches 200 acquires the display control signal from the safety PLC 400.

[0091] According to Figure 6 In the connection relationship shown in the embodiment, the display control signal quickly reaches each of the safety switches 200, and the real-time performance of the display of each of the safety switches 200 is improved.

[0092] In Figure 7 In the embodiment, the safety switches 200 and the safety PLC 400 are connected in a ring shape and are directly connected (i.e., connected in a loop shape). In this case, the display control signal is generated by the safety PLC 400. It should be noted that, in Figure 7 In the embodiment, the last-stage safety switch 200 is the master switch 200M, and the other safety switches 200 are slave switches 200S.

[0093] In Figure 7 In the embodiment, the input / output unit 219 of each of the slave switches 200S outputs the abnormality detection signal to another adjacent switch of the next stage. The input / output unit 219 of the master switch 200M outputs the abnormality detection signal to the safety PLC 400. The input / output unit of the safety PLC 400 acquires the abnormality detection signal from the master switch 200M. The processor of the safety PLC 400 generates the display control signal based on the acquired abnormality detection signal.

[0094] The input / output unit of the safety PLC 400 outputs the display control signal to the slave switch 200S of the first stage. The input / output unit 219 of the slave switch 200S of the first stage acquires the display control signal from the safety PLC 400 and outputs the display control signal to another adjacent switch (the slave switch 200S or the master switch 200M) of the next stage. The input / output unit 219 of each of the slave switches 200S except for the slave switch of the first stage acquires the display control signal from the adjacent slave switch 200S and outputs the display control signal to another adjacent slave switch (the slave switch 200S or the master switch 200M) of the next stage.

[0095] According to Figure 7According to the connection relationship shown in FIG. 6, the safety PLC 400 does not need to perform communication of the abnormality detection signal and the display control signal with all the safety switches 200 respectively. Specifically, the abnormality detection signal can be acquired from the master switch 200M, and the display control signal can be output to the slave switch 200S of the first stage. Accordingly, it is possible to reduce the load or the burden on the safety PLC 400 at the time of instruction of the display control by the safety PLC 400.

[0096] In Figure 8 , the safety switches 200 are connected in a ring shape and directly (i.e., in a loop shape). Then, the safety switch 200 of the last stage (i.e., the master switch 200M) is connected to the safety PLC 400. In this case, the display control signal is generated by the master switch 200M.

[0097] In Figure 8 , the input / output unit 219 of each of the slave switches 200S outputs the abnormality detection signal to another adjacent switch of the next stage. The input / output unit 219 of the master switch 200M outputs the abnormality detection signal to the safety PLC 400. The input / output unit of the safety PLC 400 acquires the abnormality detection signal from the master switch 200M. The processor 211 of the master switch 200M generates the display control signal based on the acquired abnormality detection signal. The input / output unit 219 of the master switch 200M outputs the display control signal directly or indirectly to each of the slave switches 200S.

[0098] According to Figure 8 , the master switch 200M does not need to perform communication of the abnormality detection signal with all the slave switches 200S respectively. Specifically, it is enough to acquire the abnormality detection signal from the adjacent slave switch 200S provided at the previous stage.

[0099] Figure 9 is a diagram showing a first transmission device example of the display control signal corresponding to the third example of the connection relationship between the plurality of safety switches 200 and the safety PLC 400 shown in Figure 8 . In Figure 9 , the abnormality detection signal is transmitted in the same manner as in Figure 8 . That is, the abnormality detection signal is transmitted in one direction to another switch of the next stage or the safety PLC 400.

[0100] Meanwhile, the display control signal is transmitted from the master switch 200M as a generation source to the slave switch 200S of the first stage, and then sequentially transmitted to another adjacent switch of the next stage. That is, the input / output unit 219 of the slave switch 200S of the first stage acquires the display control signal from the master switch 200M and outputs the display control signal to another adjacent switch (slave switch 200S or master switch 200M) of the next stage. The input / output unit 219 of each of the slave switches 200S except for the slave switch of the first stage acquires the display control signal from the adjacent slave switch 200S of the previous stage and outputs the display control signal to another adjacent slave switch (slave switch 200S or master switch 200M) of the next stage. Thus, the transmission path of the display control signal is a loop path as shown in FIG. 8. Figure 9

[0101] According to the display control signal transmission device shown in Figure 9 , it is sufficient that the display control signal is output to the slave switch 200S of the first stage. Thus, it is possible to reduce the load or the burden on the master switch 200M at the time when the master switch 200M instructs the display control.

[0102] Figure 10 is a diagram showing a first transmission device example of the display control signal corresponding to the third example of the connection relationship between the plurality of safety switches 200 and the safety PLC 400 shown in Figure 8 . In Figure 10 , the abnormality detection signal is transmitted in the same manner as in Figure 8 . That is, the abnormality detection signal is transmitted in one direction to another switch or the safety PLC 400 of the next stage.

[0103] Meanwhile, the display control signal is directly transmitted from the master switch 200M as a generation source to each of the slave switches 200S. That is, the input / output unit 219 of the master switch 200M outputs the display control signal to each of the slave switches 200S. The input / output unit 219 of each of the slave switches 200S acquires the display control signal from the master switch 200M. Thus, the transmission path of the display control signal is not a loop path.

[0104] According to the connection relationship shown in Figure 10 , the display control signal quickly reaches each of the slave switches 200S, and the real-time property of the display of each of the slave switches 200S is improved.

[0105] Next, a display example of the plurality of safety switches 200 provided on the plurality of doors 100 will be described.

[0106] Figure 11 ​is a diagram showing a first display example of the plurality of safety switches 200. In Figure 11 , the plurality of doors 100 surround the manufacturing equipment main body. The plurality of doors 100 include doors 100A, 100B, 100C, 100D, 100E, and 100F. Figure 1 For example, when the door 100D is in the open state, the safety switch 200D provided on the door 100D displays light in the display mode DM2 (e.g., red light emission). In the doors 100A, 100B, 100C, 100E, and 100F other than the door 100D, the own door is in the closed state, and the door 100D as one of the other doors is in the open state. Therefore, the safety switches 200A, 200B, 200C, 200E, and 200F other than the display of the safety switch 200D are displayed in the display mode DM4 (e.g., green flicker) based on the display control signal.

[0107] Therefore, even when the confirmer U1 cannot directly confirm the display of the safety switch 200D provided on the door 100D, the confirmer U1 can recognize that any one of the doors 100 is in the open state by confirming the safety switch 200A provided on the door 100A which can be confirmed or the safety switch 200B provided on the door 100B which can be confirmed. Therefore, the confirmer U1 can understand that the door 100D is in the open state by going to the position of the door 100 which cannot be directly confirmed and confirming the display of, for example, the safety switch 200D. Therefore, the confirmer U1 can take measures such as closing the door 100D and, for example, can safely operate the manufacturing equipment.

[0108]

[0109] is a diagram showing a second display example of the plurality of safety switches 200. In Figure 12 , the plurality of doors 100 are linearly arranged. The plurality of doors 100 include doors 100A, 100B, 100C, and 100D. Here, it is assumed that the plurality of doors 100 are arranged in the depth direction from the confirmer's view. Figure 12 For example, when the door 100C is in the open state, the safety switch 200C provided on the door 100C displays light in the display mode DM2 (e.g., red light emission). In the doors 100A, 100B, and 100D other than the door 100C, the own door is in the closed state, and the door 100C as one of the other doors is in the open state. Therefore, the safety switches 200A, 200B, and 200D other than the safety switch 200C are displayed in the display mode DM4 (e.g., green flicker) based on the display control signal.

[0110]

[0111] ​Therefore, even when the checker U1 cannot directly confirm the display of the safety switch 200C provided on the door 100C on the rear surface side of the doors 100A and 100B, the checker U1 can recognize that any of the doors 100 is in the open state by confirming the safety switch 200A provided on the door 100A which can be confirmed. Therefore, the checker U1 can understand that the door 100C is in the open state by going to the position of the door 100 which cannot be directly confirmed and confirming the display of, for example, the safety switch 200C. Therefore, the checker U1 can take measures such as closing the door 100C and, for example, can safely operate the manufacturing equipment.

[0112] Then, the display obtained by each of the safety switches will be described in a manner of comparison between the comparative example and the present embodiment. It should be noted that each of the components of the safety switch of the comparative example is shown with "X" added to the end of the reference numeral.

[0113] Figure 13 is a view showing a display based on an abnormality detection signal obtained in a plurality of safety switches 200X in the comparative example. In the comparative example, each of the safety switches 200X outputs an abnormality detection signal to other switches of a next stage, instead of outputting a display control signal. The light source 213X includes a first light source 213X1 and a second light source 213X2. In each of the safety switches 200X, the first light source 213X1 displays light based on a detection result of the own switch. The second light source 213X2 displays light based on an abnormality detection signal indicating a detection result of other switches up to a previous stage.

[0114] In Figure 13 , the safety switch 200X1, the safety switch 200X2, the safety switch 200X3, and the safety PLC 400X are connected in series in this order from the previous stage. In Figure 13 , the door 100X2 on which the safety switch 200X2 is provided is in the open state. Therefore, the safety switch 200X2 and the safety switch 200X1 of the previous stage acquire an abnormality detection signal including closing information. The safety switch 200X3 of the next stage of the safety switch 200X2 acquires an abnormality detection signal including opening information. The safety switch 200X3 outputs the abnormality detection signal including the opening information to the safety PLC 400X.

[0115] Thus, in the safety switch 200X1, the first light source 213X1 displays light in the display mode DM1 (e.g., emits green light), and the second light source 213X2 displays light in the display mode DM1. In the safety switch 200X2, the first light source 213X1 displays light in the display mode DM2 (e.g., emits red light), and the second light source 213X2 displays light in the display mode DM1. In the safety switch 200X3, the first light source 213X1 displays light in the display mode DM1, and the second light source 213X2 displays light in the display mode DM2.

[0116] Thus, in the safety switch 200X1 in the comparative example, even if the first light source 213X1 and the second light source 213X2 are confirmed, it is not possible to determine whether the other safety switches 200X detect an abnormality, i.e., whether the other doors 100X are open.

[0117] Figure 14 is a diagram illustrating display examples based on display control signals in a plurality of safety switches 200 according to an embodiment. In the present embodiment, each of the safety switches 200 outputs an abnormality detection signal to another switch of a next stage, and also outputs a display control signal. The light source 213 includes a first light source 213A and a second light source 213B. In each of the safety switches 200, the first light source 213A displays light based on a detection result of the own switch. The second light source 213B displays light based on a display control signal indicating detection results of all other switches.

[0118] In Figure 14 , the slave switch 200S1, the slave switch 200S2, the master switch 200M, and the safety PLC 400 are connected in this order in series from the previous stage. In Figure 14 , only the door 100B on which the slave switch 200S2 is provided is in an open state. Thus, the slave switch 200S2 and the slave switch 200S1 of the previous stage acquire abnormality detection signals including closing information. The master switch 200M of the next stage of the slave switch 200S2 acquires an abnormality detection signal including opening information. The master switch 200M outputs the abnormality detection signal including the opening information to the safety PLC 400. The master switch 200M or the safety PLC 400 generates a display control signal including the opening information. The generated display control signal is transmitted in this order to, for example, the slave switch 200S1, the slave switch 200S2, and the master switch 200M.

[0119] Thus, in the from switch 200S1, the first light source 213A displays light in the display mode DM1, and the second light source 213B displays light in the display mode DM2. In the from switch 200S2, the first light source 213A displays light in the display mode DM2, and the second light source 213B displays light in the display mode DM2. In the main switch 200M, the first light source 213A displays light in the display mode DM1, and the second light source 213B displays light in the display mode DM2.

[0120] As described above, the safety switch 200 according to the present embodiment, like the comparative example, can recognize and display that an abnormality exists in another switch at a subsequent stage of the safety switch 200 having an abnormality. In addition, the safety switch 200 can recognize and display that an abnormality exists in another switch at a subsequent stage by performing display based on the display control signal even in a preceding stage of the safety switch having an abnormality. Thus, the safety switch 200 can grasp the detection result of the other switches regardless of the arrangement order of the other switches, and can improve the display accuracy of the presence or absence of an abnormality in consideration of the presence or absence of an abnormality detected by another safety switch.

[0121] For example, there is a case in which the equipment 10 in which the door is installed is large and the door 100 or the safety switch 200 cannot be directly confirmed by visual confirmation by the confirmer. In this case, it is very advantageous that the situation or state of another safety switch can be grasped by the display obtained by the safety switch 200 that is visually recognizable. By the safety switch 200 according to the present embodiment, the state of each of the safety switches 200 can be grasped with high accuracy, and for example, the manufacturing equipment main body can be appropriately and safely operated.

[0122] Next, the safety output of each of the safety switches 200X will be described in the manner of comparison between the comparative example and the present embodiment. It should be noted that each of the components of the safety switch of the comparative example is shown with an "X" added to the end of the reference numeral.

[0123] Figure 15 is a view showing the output based on the abnormality detection signal in the plurality of safety switches 200X in the comparative example.

[0124] In Figure 15In this configuration, safety switches 200X1, 200X2, and 200X3, along with the safety PLC 400X, are connected in series in this order, starting from the previous stage. The input / output unit 219X of each of the safety switches 200X1, 200X2, and 200X3 outputs an abnormality detection signal to the next stage safety switch 200X in the safety PLC 400X via repeating signal lines (OSSD1 and OSSD2).

[0125] Thus, in the comparative example, the safety switch 200X outputs an anomaly detection signal through a repeating signal line in all safety switches 200X. Therefore, the configurations of all safety switches 200X are identical.

[0126] Figure 16 This is a diagram illustrating an example of the output of anomaly detection signals in a plurality of safety switches 200 according to this embodiment. It should be noted that, in Figure 16 In this context, the output of the display control signal is omitted.

[0127] exist Figure 16 In this configuration, slave switches 200S1, 200S2, 200M, and the safety PLC 400 are connected in series in this order, starting from the previous stage. For each slave switch in slave switches 200S1 and 200S2, an anomaly detection signal is output to the next-stage safety switch 200 (slave switch 200S2 and main switch 200M) via a single signal line (CHECK_OUT). Conversely, the main switch 200M outputs an anomaly detection signal to the next-stage safety PLC 400 via repeated signal lines (OSSD1 and OSSD2).

[0128] Thus, according to the switch system 5 of this embodiment, the signal line through which the abnormality detection signal is transmitted in the slave switch 200S (which is a safety switch among a plurality of safety switches 200 excluding the last-stage safety switch) is single, and the signal line through which the abnormality detection signal is transmitted in the master switch 200M (which is the last-stage safety switch among a plurality of safety switches 200) is repeated. Therefore, the configuration of the slave switch 200S can be simplified to a safety switch with fewer faults in the safety output. In addition, the master switch 200M can maintain the safety output performance without having to simplify the switch configuration to a safety switch with high importance in the safety output.

[0129] While various embodiments have been described above with reference to the accompanying drawings, it should be understood that the invention is not limited thereto. Those skilled in the art will appreciate that various changes and modifications can be conceived within the scope of the claims, and it should also be understood that such changes and modifications fall within the technical scope of the invention. Furthermore, the respective components in the embodiments described above can be optionally combined without departing from the scope of the invention.

[0130] In the above-described embodiment, the door-equipped device 10 surrounds the manufacturing device through the door 100, but the present disclosure is not limited thereto. For example, a storage cabinet or a locker (e.g., a delivery storage cabinet) can be provided instead of the manufacturing device. In addition, the door 100 can surround only a predetermined space. That is, the door-equipped device 10 can partition only the space.

[0131] In the above embodiment, the safety switch 200 detects the open state and the closed state of the door 100 as detection of the presence or absence of an abnormality, but the present disclosure is not limited thereto. An abnormality of the door 100 other than the open state and the closed state can be detected.

[0132] In the above-described embodiment, the safety switch 200 is provided on the back side of the door 100, but the present disclosure is not limited thereto, and the safety switch 200 can be provided on the front side of the door 100. In addition, although the door body 113 is constituted by, for example, a light-transmissive member, the door body 113 can be constituted by a light-non-transmissive member.

[0133] The processor can be freely and physically configured in the above-described embodiments. When a programmable processor is used, the processing content can be changed by changing the program, and thus the degree of freedom in designing the processor can be increased. The processor can be configured by one semiconductor chip, or can be physically configured by a plurality of semiconductor chips. When the processor is configured by a plurality of semiconductor chips, the control in the above-described embodiments can be implemented by different semiconductor chips, respectively. In this case, one processor can be considered to be configured by a plurality of semiconductor chips. The processor can be configured by a semiconductor chip and a member having a different function such as a capacitor. One semiconductor chip can be configured to implement the function of the processor and another function. A plurality of processors can be implemented by one processor.

[0134] As described above, in an embodiment, the safety switch 200 includes a detection unit that detects the presence or absence of an abnormality, an output unit (e.g., the input / output unit 219) that outputs an abnormality detection signal indicating a detection result of the presence or absence of an abnormality, an input unit (e.g., the input / output unit 219) that inputs a display control signal, and a display unit (e.g., the light source 213) that performs display based on the display control signal.

[0135] Accordingly, the safety switch 200 processes the abnormality detection signal based on the detection result of the presence or absence of an abnormality of a part of the other switch and the display control signal as different signals, and thus can perform display control based on the display control signal regardless of the abnormality detection signal. Accordingly, even when the safety switch 200 is disposed at a stage before the safety switch 200 in which an abnormality is detected (an abnormality is not detected) among the plurality of safety switches 200 connected in series, the safety switch 200 can perform display by acquiring the display control signal regardless of the arrangement order of the safety switch 200 in which an abnormality is detected. Accordingly, the safety switch 200 can improve the display accuracy of the presence or absence of an abnormality in consideration of the detection of the presence or absence of an abnormality by the other switch.

[0136] The display control signal can be based on the detection result of the presence or absence of an abnormality obtained by each of the safety switch 200 and another safety switch 200 (another switch).

[0137] Accordingly, the safety switch 200 can reliably display that an abnormality occurs in at least one of the safety switches in which the safety switch 200 is included, by acquiring the display control signal.

[0138] The display unit can perform display based on the display control signal and the detection result of the presence or absence of an abnormality detected by the detection unit.

[0139] Accordingly, the safety switch 200 can perform display in consideration of the display control signal and the detection result of the presence or absence of an abnormality of the own switch. It should be noted that such display can be performed by a separate display unit by display based on the display control signal and display based on the detection result of the presence or absence of an abnormality of the own switch, or can be performed in a display mode in which information based on both the display based on the display control signal and the display based on the detection result of the presence or absence of an abnormality of the own switch is considered by one display unit.

[0140] In a case where the display control signal indicates that an abnormality is detected by at least one of the safety switch 200 and another safety switch 200, the display unit can perform display in a display mode different from a display mode in a case where the display control signal indicates that neither the safety switch 200 nor another safety switch 200 detects an abnormality.

[0141] Accordingly, the safety switch 200 can achieve a one-glance confirmation of the safety switch in which an abnormality is detected among each of the safety switches, and the confirmer of the display can respond quickly to an abnormality. The confirmer can identify the detection result of the presence or absence of an abnormality of the safety switch 200 disposed, for example, in an invisible position, by confirming the display mode of the display of the visible safety switch 200.

[0142] The display unit can display information indicating that the detection unit has detected an abnormality in a case where the detection unit has detected an abnormality.

[0143] Thus, the safety switch 200 can explicitly display the detection result of the own switch. In this case, the safety switch 200 can display the detection result of the own switch in a display mode different from the display based on the display control signal.

[0144] The safety switch 200 can be provided on the door 100. The detection unit can detect the open state and the closed state of the door 100.

[0145] Thus, the safety switch 200 can perform display based on the open state and the closed state of the own door or another door on which the own switch or another switch is provided.

[0146] In addition, the switch system 5 according to the above-described embodiment includes the plurality of safety switches 200 described above. The plurality of safety switches 200 includes a master switch 200M (an example of a first safety switch) and a slave switch 200S (an example of a second safety switch). The output unit of the slave switch 200S outputs the detection result of the presence or absence of an abnormality detected by the detection unit of the slave switch 200S to the master switch 200M. The master switch 200M includes a control unit (for example, the processor 211) that outputs a display control signal to the slave switch 200S based on the detection result of the presence or absence of an abnormality detected by the detection unit of the master switch 200M and the detection result of the presence or absence of an abnormality output by the slave switch 200S.

[0147] Thus, in the switch system 5, the master switch 200M among the plurality of safety switches 200 can aggregate the detection result of the presence or absence of an abnormality obtained by the safety switches 200 and can generate and output a display control signal in consideration of the detection result of the safety switches 200. Thus, the master switch 200M can output a display control signal based on the detection result of the presence or absence of an abnormality obtained by each of the own switch and another switch, the display control signal being different from an abnormality detection signal obtained based on the detection result of the presence or absence of an abnormality of a part of the other switches. Thus, a predetermined safety switch 200 can improve the display accuracy of the presence or absence of an abnormality in consideration of the detection of the presence or absence of an abnormality by the other switches.

[0148] The plurality of safety switches 200 can be connected in a ring shape and in series.

[0149] Accordingly, the plurality of safety switches 200 can be loop-connected or ring-connected. Accordingly, the master switch 200M does not need to communicate with each of the slave switches 200S. For example, a signal can be output to the slave switch 200S of the first stage and input from the slave switch 200S of the last stage. Accordingly, the load of the input / output of the master switch 200M can be reduced.

[0150] The output unit of the master switch 200M can output the abnormality detection signal through a repeated signal line. The output unit of the slave switch 200S can output the abnormality detection signal through a single signal line.

[0151] Accordingly, the switch system 5 can maintain the performance of the safety output by the master switch 200M while simplifying the configuration of the slave switch 200S.

[0152] The switch system 5 according to the above-described embodiment includes a plurality of safety switches 200. Each of the plurality of safety switches 200 can include a detection unit that detects presence or absence of an abnormality and an output unit that outputs an abnormality detection signal indicating a detection result of the presence or absence of the abnormality. The plurality of safety switches 200 are connected in series and include a master switch 200M (an example of a first safety switch) provided at the last stage and a slave switch 200S (an example of a second safety switch) provided at a position other than the last stage. The output unit of the master switch 200M outputs the abnormality detection signal through a repeated signal line. The output unit of the slave switch 200S outputs the abnormality detection signal through a single signal line.

[0153] Accordingly, the switch system 5 can maintain the performance of the safety output by the master switch 200M while simplifying the configuration of the slave switch 200S. Accordingly, it is possible to satisfy the safety performance while reducing the cost of the entire system. In addition, even when a control device (for example, the safety PLC 400) that acquires the abnormality detection signal from the master switch 200M controls the operation of a predetermined manufacturing device in accordance with the abnormality detection signal, it is possible to prevent the safety from being reduced by notifying the abnormality detection signal with high reliability.

[0154] While the present disclosure has been described in detail with reference to particular embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure.

[0155] The present disclosure is based on Japanese Patent Application (Patent Application No. 2020-010408) filed on January 24, 2020, and the content of the Japanese Patent Application is incorporated herein by reference.

[0156] Industrial Applicability

[0157] The present disclosure is directed to a safety switch, a switch system, etc. that can improve the display accuracy of the presence or absence of an abnormality in consideration of the presence or absence of an abnormality detected by other safety switches.

[0158] List of Reference Signs

[0159] 5 Switch system

[0160] 10 Door-equipped device

[0161] 100 Door

[0162] 111 Fixed frame

[0163] 112 Movable frame

[0164] 113 Door body

[0165] 200 Safety switch

[0166] 200M Master switch

[0167] 200S Slave switch

[0168] 210 Sensor body

[0169] 211 Processor

[0170] 212 Coil

[0171] 213 Light source

[0172] 219 Input / output unit

[0173] 250 Actuator

[0174] 280 RFID tag

[0175] 400 Safety PLC

Claims

1. A safety switch, comprising: A detection unit configured to detect the presence or absence of an anomaly, wherein the anomaly indicates that a door to be monitored, which is attached to the safety switch, has been opened; An output unit configured to output an anomaly detection signal indicating the presence or absence of an anomaly in the detection result; An input unit is configured to input display control signals; The safety switch is connected to another safety switch, which is configured to monitor another door. The display control signal is generated based on anomaly detection signals from all detection units of a plurality of safety switches, including at least the aforementioned safety switch and the other safety switch. If there are no abnormalities among the safety switches, the display control signal includes a closed information signal; otherwise, the display control signal includes an open information signal. The safety switch and the other safety switch each include a display unit, and each display unit is configured to perform a display based on both a corresponding abnormality detection signal from the safety switch or the other safety switch and the display control signal.

2. The safety switch according to claim 1, in, The display unit performs the display based on the display control signal and the detection result of the presence or absence of an anomaly detected by the detection unit.

3. The safety switch according to claim 1 or 2, in, When the display control signal indicates that an abnormality is detected by at least one of the safety switch and the other safety switch, the display unit performs a display in a different mode than the display mode when the display control signal indicates that no abnormality is detected by either the safety switch or the other safety switch.

4. The safety switch according to any one of claims 1 to 3, in, The display unit displays information indicating that the detection unit has detected an abnormality when the detection unit detects an abnormality.

5. A switching system, comprising: A plurality of safety switches, each of which is a safety switch according to any one of claims 1 to 4. The plurality of safety switches includes a first safety switch and a second safety switch. The output unit of the second safety switch outputs the detection result of the presence or absence of an abnormality detected by the detection unit of the second safety switch to the first safety switch, and The first safety switch includes a control unit, which is configured to output the display control signal to the second safety switch based on the detection result of the presence or absence of an abnormality detected by the detection unit of the first safety switch and the detection result of the presence or absence of an abnormality output by the second safety switch.

6. The switching system according to claim 5, in, The multiple safety switches are connected in a ring shape and in series.

7. The switching system according to claim 5 or 6, in, The output unit of the first safety switch is configured to output the abnormality detection signal via a full-duplex signal line, and The output unit of the second safety switch is configured to output the anomaly detection signal via a single signal line.

8. A switching system, comprising: Multiple safety switches, Each of the plurality of safety switches is a safety switch according to any one of claims 1 to 4, wherein the safety switch comprises: A detection unit configured to detect the presence or absence of an anomaly, wherein the anomaly indicates that a door to which the safety switch is attached has been opened; and The output unit is configured to output an anomaly detection signal indicating whether an anomaly exists or not. The plurality of safety switches are connected in series, and the plurality of safety switches include a first safety switch located at the last stage and a second safety switch located at positions other than the last stage. The output unit of the first safety switch is configured to output the anomaly detection signal via a full-duplex signal line. The output unit of the second safety switch is configured to output the anomaly detection signal via a single signal line. The display control signal is generated based on the abnormal detection signals from all detection units among multiple safety switches. If there is no abnormality among the safety switches, the display control signal includes a closed information; otherwise, the display control signal includes an open information.

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