Wiring unit, serial cascade connector system

Abstract

To simplify wiring work without requiring a safety PLC even when a plurality of safety switches having a lock function are arranged.SOLUTION: A plurality of safety switches are cascade-connected to a wiring unit 250. The wiring unit 250 supplies power received via a power input unit (a VCC terminal P31 or a GND terminal P34) to the plurality of safety switches. The wiring unit 250 performs through-output of an OSSD input received from the most downstream safety switch to the outside of the wiring unit. The wiring unit 250 outputs upstream-facing communication data COM (a lock input or the like) based on a lock instruction (LOCK). The wiring unit 250 receives downstream-facing communication data COM (such as bundle data of AUX outputs) and outputs the communication data COM as individual AUX outputs.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a wiring unit and a serial cascade connector system for serially cascading a plurality of safety switches.

Background Art

[0002] As one of the safety components for protecting workers from danger sources such as press devices and working robots, a safety switch (also called a safety door switch or a safety door sensor) is known. When a plurality of safety switches are installed for one danger source, from the viewpoint of wiring reduction, a serial cascade connector system is often used to connect the plurality of safety switches.

[0003] FIG. 10 is a diagram showing a conventional example of a serial cascade connector system. The serial cascade connector system 100 of this conventional example includes a plurality (eight in this figure) of safety switches 110(1) to 110(8), a power supply unit 120, a safety controller 130, and a non-safety controller 140.

[0004] When matters common to each of the safety switches 110(1) to (8) are described, the numbers in parentheses (1) to (8) following the reference number can be omitted.

[0005] The safety switch 110 includes six ports: a power supply terminal P11 (VCC), a ground terminal P12 (GND), OSSD [Output Signal Switching Device] output terminals P13 and P14 (OSSD1_O and OSSD2_O), a lock input terminal P17 (LOCK), and an AUX output terminal P18 (AUX).

[0006] The OSSD output is a safety output used to indicate that a hazardous source is in a safe state. The lock input is a control input for driving the locking mechanism of the safety switch 110. The AUX output is a non-safety output (an output signal other than the OSSD output) used to indicate the status of the safety switch 110.

[0007] Furthermore, in order to cascade multiple safety switches 110 in serial mode, in addition to the six ports mentioned above, OSSD input terminals P15 and P16 (OSSD1_I and OSSD2_I) are required. The OSSD input corresponds to a safety input that receives the OSSD output from the upstream safety switch.

[0008] As an example of prior art related to the above, Patent Document 1 can be cited. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2020-27772 [Overview of the project] [Problems that the invention aims to solve]

[0010] By using the cascading connection described above, the wiring required to transmit the OSSD output can be reduced to a single wire (two wires in Figure 10 for redundancy). Therefore, the number of wires input to the safety controller 130 can be reduced relative to the total number of safety switches 110.

[0011] However, in conventional cascading connections, the safety outputs of multiple safety switches 110 are related. The primary purpose is to enable safety (for example, when the safety output of an upstream safety switch is OFF, the downstream safety switch that receives the safety output of the upstream safety switch will turn its safety output OFF regardless of its own judgment result). For this reason, the wiring for transmitting the OSSD output changes from the safety controller 130 to the adjacent safety switch 110, but the lock input and AUX output require separate connections to the equipment that outputs the lock input to the safety switch 110 and the equipment that receives the AUX output of the safety switch 110. Therefore, there is a challenge in that the same wiring as if directly connecting to each safety switch 110 without using cascading connections is required.

[0012] Another possible method to reduce the amount of wiring directly connected to the safety switch 110 is to use a safety controller or safety PLC (Programmable Logic Controller), which is known to be a device that can communicate multiple inputs and outputs to a specific safety switch 110 over a single communication line. However, in order to use a safety PLC, the user needs to program, for example, how to interpret and display the information acquired from the communication line. Therefore, although the work related to the wiring connection itself is reduced, additional work is required to make it usable. In addition, since OSSD output is also transmitted to the safety PLC, there is a problem that the safety parameters of the entire safety system will decrease. Furthermore, safety PLCs are expensive, which leads to an increase in the cost of the entire safety system. Moreover, since the combination of safety PLC and safety switch is limited to specific models, there is also the problem of low versatility.

[0013] Furthermore, the prior art described in Patent Document 1 discloses a configuration that simplifies the wiring work for safety switches without a locking function by providing separate input / output systems (terminals) corresponding to the AUX output input / output systems of each safety switch and using a cable that bundles them together. However, in this prior art, one safety switch corresponds to one input / output system. In other words, there are limitations on the number of poles in the cable and connector. Therefore, it is not possible to connect safety switches with a locking function that require a lock input. Also, the number of safety switches capable of state detection at the AUX output is limited by the number of poles in the cable and connector. In particular, if a separate input / output system for the lock input is provided, two input / output systems, one for the AUX output and one for the lock input, are required for one safety switch, so the number of connectable safety switches is easily limited by the number of poles in the cable and connector.

[0014] In view of the above problems, the present invention aims to provide a wiring unit that can simplify wiring work without requiring a safety PLC even when multiple safety switches with locking functions are installed, and a serial cascade connector system using the wiring unit. [Means for solving the problem]

[0015] The wiring unit that solves the above problem is: A wiring unit in which multiple safety switches, each having an actuator and a switch body for detecting the actuator, are connected in a cascaded configuration, A power input section for receiving power, A safety switch port having a pair of safety input terminals that receive a first safety signal, which is a pair of safety signals output by a first safety switch among a plurality of cascaded safety switches; a pair of power output terminals for supplying power received via the power input section to the plurality of safety switches; and a wiring unit communication terminal for bidirectional communication with the first safety switch, A safety output unit is internally connected to the pair of safety input terminals so as to pass through the first safety signal received via the pair of safety input terminals, Of the aforementioned plurality of safety switches, the actuator of the switch body in accordance with the instruction A lock instruction input unit that receives a lock instruction to lock a safety switch capable of locking the movement of the ET, An information output unit for individually outputting information indicating the status of each of the aforementioned multiple safety switches, The wiring unit MCU includes a wiring unit that, based on information received from the plurality of safety switches via the wiring unit communication terminal, individually outputs information indicating the status of each of the plurality of safety switches, and outputs a lock input to the lockable safety switch to instruct locking based on the lock instruction received via the lock instruction input unit, The safety output unit is internally connected to the pair of safety input terminals so that it can detect a fault using the fault detection function of the first safety switch.

[0016] Furthermore, the serial cascade connector system that solves the above problems is A first safety switch and a second safety switch, each having an actuator and a switch body that detects the actuator, A wiring unit in which the first safety switch and the second safety switch are connected in a cascade configuration, Equipped with, At least one of the first safety switch and the second safety switch is a lockable safety switch that includes a locking mechanism capable of locking the movement of the actuator in response to a lock input. The first safety switch is, A pair of first safety input terminals for receiving the second safety signal, which is a pair of safety signals output by the second safety switch, The wiring unit is provided with a pair of first safety output terminals for outputting a pair of safety signals, which are first safety signals. A first terminal for bidirectional communication with the second safety switch, A second terminal for two-way communication with the wiring unit, A detection unit that detects that the actuator is within a predetermined range with respect to the switch body, Output the first safety signal based on the second safety signal received via the first safety input terminal and the detection result by the detection unit, and output information indicating the state of the first safety switch and the second safety switch based on the information indicating the state of the second safety switch received via the first terminal via the second terminal. A safety switch MCU, A failure detection unit that detects a failure of the first safety switch, The wiring unit, A pair of safety input terminals for receiving the first safety signal, a power input unit for receiving power, a pair of power output terminals for supplying the power received via the power input unit to the first safety switch and the second safety switch, and a wiring unit communication terminal for two-way communication with the first safety switch. A safety switch port having, A safety output unit internally connected to the pair of safety input terminals so as to thruster-output the first safety signal received via the safety input terminals, A lock instruction input unit that receives a lock instruction for locking the lockable safety switch, An information output unit for individually outputting information indicating the state of each of the plurality of safety switches, Based on the information received via the wiring unit communication terminal, individually output information indicating the state of the first safety switch and information indicating the state of the second safety switch, and based on the lock instruction received via the lock instruction input unit. A wiring unit MCU that outputs a lock input for instructing locking to the lockable safety switch via the wiring unit communication terminal, The safety output unit is internally connected to the pair of safety input terminals so that a failure can be detected by a failure detection unit provided in the first safety switch at a destination that receives the first safety signal thruster-output from the safety output unit.

[0017] Other features, elements, steps, advantages, and characteristics will become more apparent from the following embodiments for carrying out the invention and the accompanying drawings related thereto.

Advantages of the Invention

[0018] According to the present invention, it is possible to provide a serial cascade connector system that can simplify the wiring laying work without requiring a safety PLC even when a plurality of safety switches with lock functions are arranged.

Brief Description of the Drawings

[0019] [Figure 1] Figure showing a first embodiment of the serial cascade connector system [Figure 2] Figure showing a second embodiment of the serial cascade connector system [Figure 3] Figure showing an application example of the serial cascade connector system [Figure 4] Figure showing the appearance of the wiring-saving unit [Figure 5] Figure showing the functional block of the wiring-saving unit [Figure 6] Figure showing an application example of the safety switch [Figure 7] Figure showing the functional block of the safety switch [Figure 8] Figure showing an example of signal processing in the safety switch [Figure 9] Figure showing an example of the adhesion determination process [Figure 10] Figure showing a conventional example of the serial cascade connector system

Embodiments for Carrying Out the Invention

[0020] <Serial Cascade Connector System (First Embodiment)> Figure 1 shows a first embodiment of a serial cascade connector system. The serial cascade connector system 200 of the first embodiment includes a plurality (eight in this figure) of safety switches 210(1) to 210(8), a power supply unit 220, a safety controller 230, a non-safety controller 240, and a wiring-saving unit 250.

[0021] Note that when explaining matters common to each of the safety switches 210(1) to (8), the parenthetical numbers (1) to (8) following the reference number may be omitted.

[0022] The safety switch 210 has eight ports: power terminal P21 (VCC), ground terminal P22 (GND), OSSD output terminals P23 and P24 (OSSD1_O and OSSD2_O), OSSD input terminals P25 and P26 (OSSD1_I and OSSD2_I), downstream communication terminal P27 (COM_D), and upstream communication terminal P28 (COM_U).

[0023] The safety switch 210 comprises a switch body and an actuator (neither of which are shown), and is arranged to detect the open / closed state of the corresponding door. Furthermore, at least one of the safety switches 210(1) to 210(8) is equipped with a locking mechanism (such as an electromagnet) that can lock the movement of the actuator in response to a lock input.

[0024] Of the safety switches 210(1) to 210(8), the upstream safety switch 210(8) sends an OSSD output to the safety switch 210(7) connected downstream of it, based on the open / closed state of the door it corresponds to.

[0025] Each intermediate safety switch 210(i) (where i=2, 3, ..., 7) outputs the OSSD output from the safety switch 210(i+1) connected to its upstream side to OSS It receives the input as a D input and, based on the OSSD input and the open / closed state of the corresponding door, sends an OSSD output to the safety switch 210(i-1) connected downstream of itself.

[0026] The downstream safety switch 210(1) receives the OSSD output from the safety switch 210(2) connected upstream as an OSSD input, and sends an OSSD output to the wiring-saving unit 250 connected downstream based on the OSSD input and the open / closed state of the door it corresponds to.

[0027] The OSSD output from safety switch 210(1) to the wiring-saving unit 250 is an ON signal (operation permission signal) when all the doors corresponding to each of the safety switches 210(1) to 210(8) are closed, and an OFF signal (operation disallowance signal) when even one door is not closed.

[0028] Furthermore, the downstream safety switch 210(1) communicates bidirectionally with the wiring-saving unit 250 connected to the downstream communication terminal P27(COM_D), and also communicates bidirectionally with the safety switch 210(2) connected to the upstream communication terminal P28(COM_U). Similarly, the intermediate safety switches 210(i) communicate bidirectionally with the safety switch 210(i-1) connected to the downstream communication terminal P27(COM_D), and also communicate bidirectionally with the safety switch 210(i+1) connected to the upstream communication terminal P28(COM_U). In the above bidirectional communication, the AUX output and lock input from the conventional example (Figure 10) are exchanged as communication data.

[0029] Focusing on the AUX output, the upstream safety switch 210(8) outputs AUX output based on the open / closed, locked, and error states of the door it controls as communication data for downstream. The next downstream safety switch 210(7) superimposes its own AUX output onto the communication data from upstream and outputs it downstream. Similar signal processing is performed thereafter. As a result, the downstream communication data output from the downstream safety switch 210(1) to the wiring-saving unit 250 contains the combined content of all AUX outputs from safety switches 210(1) to 210(8).

[0030] Safety switch 210(1) corresponds to the "first safety switch". Safety switch 210(2), which is connected upstream of safety switch 210(1), corresponds to the "second safety switch". The wiring-saving unit 250, which is connected downstream of safety switch 210(1), corresponds to the "wiring unit". The safety controller 230, which is connected to the wiring-saving unit 250, corresponds to the "safety control device".

[0031] The OSSD outputs (OSSD1_O and OSSD2_O) sent from safety switch 210(1) to the wiring-saving unit 250 correspond to the "first safety signal". The OSSD inputs (OSSD1_I and OSSD2_I) sent from safety switch 210(2) to safety switch 210(1) correspond to the "second safety signal".

[0032] The communication data output from safety switch 210(1) to the wiring-saving unit 250, that is, the communication data which combines the AUX outputs (AUX1 to AUX8) indicating the status of each safety switch 210(1) to 210(8), corresponds to the "first status information". The communication data output from safety switch 210(2) to safety switch 210(1), that is, the communication data which combines the AUX outputs (AUX2 to AUX8) indicating the status of each safety switch 210(2) to 210(8), corresponds to the "second status information".

[0033] In the safety switch 210(1), OSSD input terminals P25 and P26 (OSSD1_I and OSSD2_I) receive OSSD input from the safety switch 210(2). This corresponds to the "first safety input terminal". OSSD output terminals P23 and P24 (OSSD1_O and OSSD2_O) correspond to the "first safety output terminal" for outputting OSSD output to the wiring-saving unit 250.

[0034] Furthermore, in the safety switch 210(1), the upstream communication terminal P28 (COM_U) corresponds to an "upstream communication terminal" that receives downstream communication data (=AUX output) from the safety switch 210(2) while outputting upstream communication data (=lock input) to the safety switch 210(2). On the other hand, the downstream communication terminal P27 (COM_D) corresponds to a "downstream communication terminal" that receives upstream communication data (=lock input) from the wiring-saving unit 250 while outputting downstream communication data (=AUX output) to the wiring-saving unit 250.

[0035] The wiring-saving unit 250 is installed between the downstream safety switch 210(1), the power supply unit 220, the safety controller 230, and the non-safety controller 240.

[0036] The wiring-saving unit 250 operates by receiving input voltage VCC and ground voltage GND from the power supply unit 220. The wiring-saving unit 250 also functions as a power supply path from the power supply unit 220 to the safety switches 210(1) to 210(8).

[0037] Furthermore, the wiring-saving unit 250 passes the OSSD outputs (OSSD1 and OSSD2) received from the safety switch 210(1) through to the safety controller 230. Here, "pass-through output" means that no logic processing is applied to the OSSD outputs. In other words, even if a buffer is provided on the signal path through which the OSSD outputs are transmitted, or if the OSSD outputs are biased, the wiring-saving unit 250 will still "pass through" the OSSD outputs.

[0038] Furthermore, the wiring-saving unit 250 receives a lock instruction (LOCK) from the safety controller 230 and outputs upstream communication data (=lock input) to the safety switch 210(1) based on the lock instruction (LOCK). The above lock input is transmitted sequentially from the downstream safety switch 210(1) to the upstream safety switch 210(8). Therefore, among the safety switches 210(1) to 210(8), those equipped with a locking mechanism (such as an electromagnet) can lock the movement of the actuator in response to the lock input.

[0039] Furthermore, the wiring-saving unit 250 receives downstream communication data (= bundled data of AUX outputs) from the safety switch 210(1), separates it into individual AUX outputs (AUX1 to AUX8), and outputs it to the non-safety controller 240. Therefore, the non-safety controller 240 can individually ascertain the status of each of the safety switches 210(1) to 210(8).

[0040] Thus, with the serial cascade connector system 200 of this embodiment, just like the conventional example (Figure 10), the wiring for transmitting the OSSD output can be reduced to a single wire (two wires in Figure 1 for redundancy).

[0041] Furthermore, the wiring-saving unit 250 has the function of performing bidirectional communication with the safety switch 210(1) (and by extension all safety switches 210(1) to 210(8)) via a single communication line. In other words, the 16 wires (= LOCK × 8 wires + AUX × 8 wires) that were laid between the safety controller 130 and non-safety controller 140 and the safety switches 110(1) to 110(8) in the conventional example described above (Figure 10) are consolidated into a single wire.

[0042] Therefore, it becomes possible to reduce the number of wires input to the wiring-saving unit 250 relative to the total number of safety switches 210(1) to 210(8). As a result, the safety switch 210 (1) to 210(8) can be controlled together, and the wiring work required for this can be simplified.

[0043] Furthermore, the serial cascade connector system 200 of this embodiment does not require a safety controller or safety PLC that has the function of communicating with specific sensors. If a safety PLC is introduced in place of the safety controller 230 and non-safety controller 240, it is necessary to program how the safety PLC will process the signals from the controlled devices (in this case, safety switches 210(1) to 210(8)).

[0044] On the other hand, the wiring-saving unit 250 (especially the MCU built into it) has pre-configured settings for what kind of signal input / output processing (and display processing) should be performed between the safety switches 210(1) to 210(8) and the safety controller 230 and non-safety controller 240. Therefore, the safety controller 230 and non-safety controller 240 can operate as if the safety switches 210(1) to 210(8) were directly connected to the safety controller 230 and non-safety controller 240, respectively.

[0045] Furthermore, when a safety PLC is introduced in place of the safety controller 230 and non-safety controller 240, the safety PLC receives OSSD output (safety output) in addition to AUX output (non-safety output). In other words, the safety PLC is involved in the signal system that exchanges OSSD output (safety output). In a safety system composed of multiple safety devices, the safety parameters of the entire safety system are evaluated based on the failure rate of each safety device that constitutes it. Therefore, it can be said that the incorporation of a safety PLC with complex functions into a safety system has a significant impact on the safety parameters.

[0046] On the other hand, the wiring-saving unit 250 is not a device that performs any logic processing on the OSSD output before passing it on, like a safety PLC. Instead, it directly passes the OSSD output (OSSD1 and OSSD2) input from the safety switch 210(1) to the safety controller 230. Therefore, even if the wiring-saving unit 250 is incorporated into the safety system, the impact on safety parameters can be minimized. Furthermore, as described later, the safety switch 210 can detect a fault that occurs within itself and reflect the fault detection result in the OSSD output. For this reason, the fault detection function of the safety switch 210 can be utilized as is.

[0047] Furthermore, unlike the prior art described in Patent Document 1, the serial cascade connector system 200 of this embodiment makes it possible to detect the state of more safety switches than the number of input / output systems (terminals) of the AUX output.

[0048] As shown in this diagram, five or fewer signal wires are sufficient to connect the safety switch 210(1) and the wiring-saving unit 250. Therefore, a general-purpose M12 connector cable can be used.

[0049] <Considerations regarding lock timing> Incidentally, in the serial cascade connector system 200 of this embodiment, a lock input is transmitted to each of the safety switches 210(1) to 210(8) by the upstream communication data output from the safety controller 230.

[0050] In this case, if all of the safety switches 210(1) to 210(8) that are the target of the input are locked simultaneously, depending on the specifications of the equipment, an excessive current may flow through the power line or the equipment may not operate normally due to a voltage drop across the cable resistance. Considering this, it is preferable to control the lock timing of each of the safety switches 210(1) to 210(8) with a staggered timing.

[0051] In other words, the serial cascade connector system 200 is preferably configured such that when the wiring-saving unit 250 receives a lock instruction (LOCK) from the safety controller 230, a lock input for driving the locking mechanism of the upstream safety switch 210(2) is input to the safety switch 210(2) with a time delay, at a different timing than when the locking mechanism of the downstream safety switch 210(1) is driven. The same applies to the further upstream safety switches 210(3) to 210(8).

[0052] For example, consider a case where the upstream communication data output from the wiring-saving unit 250 includes a single lock instruction bit. In this case, without some kind of countermeasure, all of the locks of safety switches 210(1) to 210(8) could operate almost simultaneously.

[0053] Therefore, a delay function for the lock instruction bit may be incorporated into at least one of the safety switches 210(1) to 210(7) other than the upstreammost one. One way to implement this delay function is, for example, to start its own locking operation when it recognizes that the above-mentioned lock instruction bit is set, while simultaneously clearing the lock instruction bit and sending it to its upstream side, and then resetting the lock instruction bit and sending it to its upstream side when its own locking operation is complete. With such a delay function, the timing at which the lock instruction bit is transmitted to the upstream side can be delayed, making it possible to stagger the locking timings of each of the safety switches 210(1) to 210(8).

[0054] <Serial Cascade Connector System (Second Embodiment)> Figure 2 shows a second embodiment of the serial cascade connector system. The serial cascade connector system 200 of this embodiment is based on the first embodiment (Figure 1) described above, but the wiring-saving unit 250 is equipped with multiple ports (two systems, port A and port B, in this figure).

[0055] Six safety switches 210(A1) to 210(A6) are cascaded in series to port A of the wiring-saving unit 250 via connectors CNT1 to CNT6 and cables CBL1 to CBL8. Connectors CNT1 to CNT6 are equipped with a downstream socket, an upstream socket, and a switch-side socket, respectively.

[0056] Port A of the wiring-saving unit 250 is connected to the downstream socket of connector CNT1 via cable CBL1. The upstream socket of connector CNT1 is connected to the downstream socket of connector CNT2 via cable CBL2. The upstream socket of connector CNT2 is connected to the downstream socket of connector CNT3 via cable CBL3. The upstream socket of connector CNT3 is connected to the downstream socket of connector CNT4 via cable CBL4. The upstream socket of connector CNT4 is connected to the downstream socket of connector CNT5 via cable CBL5. The upstream socket of connector CNT5 is connected to the downstream socket of connector CNT6 via cable CBL6. The upstream socket of connector CNT6 is connected to terminator TM1 (also called a termination resistor or dummy load).

[0057] The switch-side sockets of connectors CNT1, CNT2, CNT5, and CNT6 are directly connected to safety switches 210(A1), 210(A2), 210(A5), and 210(A6), respectively. Safety switches 210(A1), 210(A2), 210(A5), and 210(A6) are all equipped with an electromagnet-based locking mechanism. Therefore, safety switches 210(A1), 210(A2), 210(A5), and 210(A6) can perform door locking upon receiving a lock input transmitted from the wiring-saving unit 250.

[0058] The switch-side socket of connector CNT3 is connected to safety switch 210(A3) via cable CBL7. The switch-side socket of connector CNT4 is connected to safety switch 210(A4) via cable CBL8. Safety switch 210(A3) has a locking mechanism using a spring lock. On the other hand, safety switch 210(A4) does not have any locking mechanism. Therefore, safety switches 210(A3) and 210(A4) cannot lock the door even when they receive a lock input transmitted from the wiring-saving unit 250.

[0059] Two safety switches 210(B1) and 210(B2) are cascaded in series to port B of the wiring-saving unit 250 via connectors CNT7 and CNT8 and cables CBL9 and CBL10. Connectors CNT7 and CNT8 are equipped with a downstream socket, an upstream socket, and a switch-side socket, respectively.

[0060] Port B of the wiring-saving unit 250 is connected to the downstream socket of connector CNT7 via cable CBL9. The upstream socket of connector CNT7 is connected to the downstream socket of connector CNT8 via cable CBL10. The upstream socket of connector CNT8 is connected to terminator TM2.

[0061] The switch-side sockets of connectors CNT7 and CNT8 are directly connected to safety switches 210(B1) and 210(B2), respectively. Both safety switches 210(B1) and 210(B2) are equipped with an electromagnet-based locking mechanism. Therefore, safety switches 210(B1) and 210(B2) can perform door locking upon receiving a lock input transmitted from the wiring-saving unit 250.

[0062] As described above, in the serial cascade connector system 200 of this embodiment, a total of up to eight safety switches can be connected to ports A and B of the wiring-saving unit 250. That is, if x safety switches (where 0 ≤ x ≤ 8) are connected to port A, then up to (8-x) safety switches can be connected to port B.

[0063] The wiring-saving unit 250 operates by receiving input voltage VCC and ground voltage GND from the power supply unit 220. The wiring-saving unit 250 also functions as a power supply path from the power supply unit 220 to ports A and B, respectively.

[0064] Furthermore, the wiring-saving unit 250 passes the OSSD outputs (OSSD1_A / B and OSSD2_A / B) that are input from safety switches 210(A1) and 210(B1) to ports A and B, respectively, to the safety controller 230.

[0065] Furthermore, the wiring-saving unit 250 receives two sets of lock instructions (LOCK_A / B) from the safety controller 230 and outputs them as upstream communication data to the safety switches 210(A1) and 210(B1) from ports A and B, respectively.

[0066] Furthermore, the wiring-saving unit 250 receives downstream communication data input to ports A and B respectively from safety switches 210(A1) and 210(B1), separates it into individual AUX outputs (AUX1 to AUX8), and outputs it to the non-safety controller 240.

[0067] As described above, the wiring-saving unit 250 operates basically the same as the first embodiment (Figure 1), except that it is equipped with two ports, A and B. Therefore, the wiring work required to control the safety switches 210(A1) to 210(A6), 210(B1), and 210(B2) together can be simplified.

[0068] Figure 3 shows an example of the application of the serial cascade connector system 200 in the second embodiment. As shown in this figure, consider a case where a hazardous source (such as a machine tool) is surrounded on all four sides by isolation walls, and multiple doors are provided on different sides. In this case, it is desirable that the wiring to the safety switches provided at each door be branched into multiple systems from the wiring-saving unit 250 for ease of wiring installation.

[0069] Referring to this diagram, port A of the wiring-saving unit 250 is cascaded with safety switches 210(A1) to 210(A3) located on the partition wall at the front of the page. On the other hand, port B of the wiring-saving unit 250 is cascaded with safety switches 210(B1) and 210(B2) located on the partition wall at the back of the page.

[0070] In addition to the wiring reasons mentioned above, there may be cases where it is desirable to individually configure the input / output control (e.g., lock control) of the safety switches installed on the worker door and the maintenance door. For this purpose, it is desirable that the wiring-saving unit 250 has multiple ports, with the OSSD output and lock input being independent for each system.

[0071] <Wiring-saving unit> Figure 4 shows the external appearance of the wiring-saving unit 250 in the second embodiment. Referring to this figure, the wiring-saving unit 250 includes switch connection connectors 251A and 251B, OSSD indicator lights 252A and 252B, a switch status indicator light 253, and a setting switching switch 254.

[0072] The switch connector 251A is the connector corresponding to port A. Following Figure 2, cable CBL1 is connected to the switch connector 251A. For example, the switch connector 251A may be located towards the right of the upper area in a front view of the wiring-saving unit 250, as shown in this figure.

[0073] The switch connector 251B is the connector corresponding to port B. Following Figure 2, cable CBL9 is connected to the switch connector 251B. For example, as shown in this figure, the switch connector 251B may be located below the switch connector 251B in a front view of the wiring-saving unit 250. In this embodiment, ports A and B are each composed of switch connectors 251A and 251B provided on the housing of the wiring-saving unit 250, but they may also be composed of a cable extending from the inside to the outside of the housing of the wiring-saving unit 250, with a connector provided at the end of the cable.

[0074] The OSSD indicator light 252A is controlled to turn on and off according to the OSSD output of the safety switch 210 cascaded to port A. Following Figure 2, the OSSD indicator light 252A lights up green when all OSSD outputs of safety switches 210(A1) to 210(A6) are ON, and turns off when at least one is OFF. For example, as shown in this figure, the OSSD indicator light 252A may be located in the upper right corner of the switch connection connector 251A in a front view of the wiring-saving unit 250.

[0075] The OSSD indicator light 252B is controlled to turn on and off according to the OSSD output of the safety switch 210, which is cascaded to port B. Following Figure 2, the OSSD indicator light 252B lights up green when both the OSSD outputs of safety switches 210(B1) and 210(B2) are ON, and turns off when at least one of them is OFF. For example, as shown in this figure, the OSSD indicator light 252B may be located in the upper right corner of the switch connection connector 251B in a front view of the wiring-saving unit 250.

[0076] The switch status indicator lights 253 display the status of up to eight safety switches 210 based on the downstream communication data (= bundled data of AUX output) input to ports A and B, respectively. For example, as shown in this figure, the switch status indicator lights 253 may be arranged in a vertical line of eight on the left side of the upper area (= to the left of switch connection connectors 251A and 251B, respectively) when viewed from the front of the wiring-saving unit 250.

[0077] The eight switch status indicator lights 253 arranged in a row correspond to the safety switches 210 connected to port A, from top to bottom, and to the safety switches 210 connected to port B, from bottom to top. Following Figure 2, of the eight switch status indicator lights 253, the top six indicate the status of safety switches 210(A1) to 210(A6), and the bottom two indicate the status of safety switches 210(B1) and 210(B2). With this arrangement, it becomes easy to distinguish the status of safety switches 210(A1) to 210(A6), 210(B1), and 210(B2) connected to ports A and B, respectively, with a minimum number of indicator lights.

[0078] The correspondence between the on / off state of the switch status indicator light 253 and the safety switch 210 is as follows: For example, when the safety switch 210 detects and locks the actuator 212, the corresponding switch status indicator light 253 lights up green. When the safety switch 210 detects and unlocks the actuator 212, the corresponding switch status indicator light 253 blinks green. When the safety switch 210 does not detect the actuator 212, the corresponding switch status indicator light 253 lights up red. When the safety switch 210 is in an error state, the corresponding switch status indicator light 253 blinks red. When the safety switch 210 is not connected, the switch status indicator light 253 is off.

[0079] Thus, the switch status indicator light 253 has more display types (= green solid, green blinking, red solid, red blinking, and off) compared to the OSSD indicator lights 252A and 252B mentioned earlier.

[0080] The setting switch 254 is used to switch the various settings of the safety switches 210, which are cascaded to ports A and B, respectively. For example, as shown in this figure, the setting switch 254 may be arranged in a vertical line of five in the lower area when viewed from the front of the wiring-saving unit 250.

[0081] The setting parameters that can be switched using the setting switch 254 include the OSSD output format (PNP / NPN), OSSD output conditions (lock-linked / open-open-linked), fixed off state for the large indicator light, green off state for the large indicator light, and switching of the latch force for the electromagnet lock. The input result of the setting switch 254 should be included in the upstream communication data output from the wiring-saving unit 250 as a setting switching command.

[0082] Figure 5 shows the functional block of the wiring-saving unit 250 in the second embodiment. The wiring-saving unit 250 in this configuration example is equipped with a plurality of external terminals P31 to P48 and P49(1) to P49(8) (VCC, VCC_A, VCC_B, GND, GND_A, GND_B, OSSD1_I_A, OSSD2_I_A, OSSD1_O_A, OSSD2_O_A, OSSD1_I_B, OSSD2_I_B, OSSD1_O_B, OSSD2_O_B, COM_A, COM_B, LOCK_A, LOCK_B, and AUX1 to AUX8) as means for establishing electrical conductivity with the outside of the unit.

[0083] Terminal P31 VCC is a power input terminal for receiving the input voltage VCC from the power supply unit 220. Terminal P32 VCC_A is connected to the VCC terminal inside the wiring-saving unit 250 and is a power output terminal for outputting the input voltage VCC to port A. Terminal P33 VCC_B is connected to the VCC terminal inside the wiring-saving unit 250 and is a power output terminal for outputting the input voltage VCC to port B.

[0084] The GND terminal P34 is a ground input terminal for receiving the ground voltage GND from the power supply unit 220. The GND_A terminal P35 is connected to the GND terminal inside the wiring-saving unit 250 and is a ground output terminal for outputting the ground voltage GND to port A. The GND_B terminal P36 is connected to the GND terminal inside the wiring-saving unit 250 and is a ground output terminal for outputting the ground voltage GND to port B. The VCC terminal P31 and the GND terminal P34 function as power input sections for supplying power to the wiring unit 250. Both the VCC terminal P31 and the GND terminal P34 are located at the ends of cables extending from the housing of the wiring unit 250. In other words, the power input section for supplying power to the wiring unit 250 is a cable.

[0085] The OSSD1_I_A terminal P37 and OSSD2_I_A terminal P38 are safety input terminals for receiving the OSSD outputs (OSSD1 and OSSD2) from the safety switch 210 connected to port A, respectively. The OSSD1_O_A terminal P39 and OSSD2_O_A terminal P40 are connected to the OSSD1_I_A terminal and OSSD2_I_A terminal, respectively, inside the wiring-saving unit 250, and are safety output terminals for passing the OSSD output of port A through to the safety controller 230. The OSSD1_O_A terminal P39 and OSSD2_O_A terminal P40 are located at the ends of cables extending from the housing of the wiring unit 250. In other words, the safety output section for passing the OSSD output of port A through is the cable.

[0086] The OSSD1_I_B terminal P41 and OSSD2_I_B terminal P42 are safety input terminals for receiving the OSSD outputs (OSSD1 and OSSD2) from the safety switch 210 connected to port B, respectively. The OSSD1_O_B terminal P43 and OSSD2_O_B terminal P44 are connected to the OSSD1_I_B terminal and OSSD2_I_B terminal, respectively, inside the wiring-saving unit 250, and are safety output terminals for passing the OSSD output of port B through to the safety controller 230. The OSSD1_O_B terminal P43 and OSSD2_O_B terminal P440 are provided at the ends of the cables extending from the housing of the wiring unit 250. In other words, the safety output section for passing the OSSD output of port B through is the cable.

[0087] COM_A terminal P45 is a wiring unit communication terminal that receives downstream communication data (= bundled data of AUX output at port A) from the safety switch 210 connected to port A, and outputs upstream communication data (= lock input at port A).

[0088] COM_B terminal P46 is a wiring unit communication terminal that receives downstream communication data (= bundled data of AUX output at port B) from the safety switch 210 connected to port B, and outputs upstream communication data (= lock input at port B).

[0089] LOCK_A terminal P47 and LOCK_B terminal P48 are lock instruction input terminals that receive lock instructions for ports A and B respectively from the safety controller 230. LOCK_A terminal P47 and LOCK_B terminal P48 are located at the ends of cables extending from the housing of the wiring unit 250. In other words, the lock instruction input section that receives lock instructions is the cable.

[0090] Terminals P49(1) to P49(8) of AUX1 are non-safety output terminals for individually outputting AUX outputs (AUX1 to AUX8) corresponding to up to eight safety switches 210 connected to ports A and B to the non-safety controller 240. Terminals P49(1) to P49(8) of AUX1 are located at the ends of cables extending from the housing of the wiring unit 250. In other words, they individually output the status of the safety switches 210. The information output section for this purpose is a cable. In this embodiment, the power input section for supplying power to the wiring unit 250, the safety output section for passing through the OSSD outputs of port A and port B, the lock instruction input section for receiving lock instructions, and the information output section for individually outputting the status of the safety switch 210 are all cables, but they may also be configured as terminal blocks having corresponding terminals.

[0091] Furthermore, the wiring-saving unit 250 includes, as its functional blocks, an MCU 250a, a lock input unit 250b, a voltage regulator 250c, an OSSD monitoring unit 250d, an AUX output unit 250e, and an LED [Light Emitting Diode] 250f.

[0092] The MCU250a (equivalent to the wiring unit MCU) individually determines the status of up to eight safety switches 210 cascaded to ports A and B based on the downstream communication data (bundle data of AUX outputs at ports A and B) received via COM_A terminal P45 and COM_B terminal P46, respectively.

[0093] The MCU250a controls the AUX output unit 250e and the LED 250f respectively, thereby performing external output control and display output control (= switch status display control) according to the state of each safety switch 210. The MCU250a also has a function to receive OSSD output monitoring results from the OSSD monitoring unit 250d and perform display output control (= OSSD display control).

[0094] Furthermore, based on the lock instructions received from the LOCK_A terminal P47 and LOCK_B terminal P48 via the lock input unit 250b, the MCU250a outputs upstream communication data (= lock inputs for ports A and B respectively) from the COM_A terminal P45 and COM_B terminal P46.

[0095] The above signal input / output processing (and display processing) can be pre-programmed into the MCU250a.

[0096] The lock input unit 250b receives lock instructions for ports A and B from the safety controller 230 via LOCK_A terminal P47 and LOCK_B terminal P48, respectively, and sends these lock instructions to the MCU 250a.

[0097] The voltage regulator 250c receives input voltage VCC (e.g., DC +24V) and ground voltage GND (e.g., 0V) from the power supply unit 220 via VCC terminal P31 and GND terminal P34, and supplies power to each part of the wiring-saving unit 250. For example, a DC-DC converter can be used as the voltage regulator 250c.

[0098] The OSSD monitoring unit 250d corresponds to a safety signal monitoring unit that monitors the OSSD output transmitted within the wiring-saving unit 250 and outputs the monitoring results to the MCU 250a. For example, the OSSD monitoring unit 250d only needs to monitor one of the duplicated OSSD outputs (OSSD1 and OSSD2), namely OSSD1.

[0099] Referring to this diagram, the OSSD monitoring unit 250d extracts and monitors the OSSD output (OSSD1_A) of port A from the safety output line laid between OSSD1_I_A terminal P37 and OSSD1_O_A terminal P39, and also extracts and monitors the OSSD output (OSSD1_B) of port B from the safety output line laid between OSSD1_I_B terminal P41 and OSSD1_O_B terminal P43.

[0100] The OSSD monitoring unit 250d monitors the OSSD output (OSSD1_A and The system may include a transmitting unit that transmits a monitoring signal based on OSSD1_B), and a receiving unit that receives the above monitoring signal through isolated communication with the transmitting unit and outputs it to the MCU250a.

[0101] For example, the transmitting unit described above may transmit a non-electrical monitoring signal (e.g., an optical signal) based on the OSSD outputs (OSSD1_A and OSSD1_B) to be monitored. In this case, a photocoupler including a light-emitting element (such as a light-emitting diode) and a light-receiving element (such as a phototransistor) can be suitably used as the transmitting unit and the receiving unit.

[0102] Of course, the method of isolated communication within the OSSD monitoring unit 250d (i.e., between the transmitting unit and the receiving unit as described above) is not limited to optical isolation; transformer isolation or capacitive isolation may also be employed.

[0103] As mentioned earlier, in a safety system composed of multiple safety devices, the safety parameters of the entire safety system are evaluated based on the failure rate of each safety device that constitutes it. Therefore, it is preferable to have as few components as possible that can affect the OSSD output.

[0104] Considering this, it is desirable that the MCU250a be isolated from the safety output line through which the OSSD output is transmitted. With this configuration, the OSSD output itself passes through the wiring-saving unit 250 via a dedicated safety output line, and the MCU25a can monitor the OSSD output while ensuring its independence.

[0105] The best mode, which completely eliminates any impact on OSSD output, is to omit the OSSD monitoring unit 250d. However, some existing safety switches do not have the function to output the safety status (≒door open / closed status) as communication data, and it is conceivable that such safety switches may be connected to the wiring-saving unit 250. Therefore, in order to understand and display the safety status of at least each port, it is necessary to provide the OSSD monitoring unit 250d in the wiring-saving unit 250.

[0106] The AUX output unit 250e outputs the AUX outputs (AUX1 to AUX8) for each safety switch 210 individually to the non-safety controller 240 in accordance with the instructions of the MCU 205a.

[0107] LED250f displays OSSD information and switch status information according to instructions from MCU205a. LED250f can be understood, for example, as the OSSD indicator lights 252A and 252B, and the switch status indicator light 253, as shown in Figure 4.

[0108] <Safety switch (application example)> Figure 6 shows an example of the application of the safety switch 210. In this figure, a guard 300 surrounds a hazardous source such as a machine tool. The guard 300 is an example of safety protection through isolation, and in this figure, a part of the enclosure box equipped with an isolation wall (particularly the area around the door where the safety switch is installed) is depicted. However, the depiction in this figure is merely an example, and it can also be understood by replacing the isolation wall in this figure with a metal fence or the like.

[0109] The guard 300 is equipped with two doors 301L and 301R, which are movable guards that can be opened and closed. Doors 301L and 301R may be made of transparent resin or tempered glass, respectively. A safety switch 210L is provided in the upper right corner of the left door 301L. A safety switch 210R is provided in the upper left corner of the right door 301R. Safety switches 210L and 210R can be understood as corresponding to the safety switch 210 described above.

[0110] Note that the letters L and R following the reference number indicate multiple identical or similar parts. These letters are used to distinguish between materials. When describing features common to multiple components, the letters L and R are omitted.

[0111] The switch body 211L of the safety switch 210L and the switch body 211R of the safety switch 210R are each fixed to the door frame 302 of the guard 300. Thus, it is desirable that the switch body 211 to which the cable is connected be installed on a fixed door frame 302 rather than on a door 301 that can be opened and closed (moved).

[0112] On the other hand, the actuator 212L of the safety switch 210L is fixed to a support member 303L which is fixed to the door 301L. Also, the actuator 212R of the safety switch 210R is fixed to a support member 303R which is fixed to the door 301R.

[0113] Furthermore, the safety switch 210, as a safety function contributing to the safety system, detects whether the actuator 212 is within a predetermined range relative to the switch body 211, and outputs the detection result as a safety signal (OSSD).

[0114] For example, when the door 301 of the guard 300 is closed, the RFID of the actuator 212 installed on the door 301 comes into close proximity to the detection unit (antenna coil) of the switch body 211 installed on the door frame 302. At this time, the switch body 211 detects that the actuator 212 is within a predetermined range relative to the switch body 211, i.e., that the door 301 is closed, based on the RFID being identified by the detection unit.

[0115] On the other hand, when the door 301 of the guard 300 is opened, the RFID of the actuator 211 installed on the door 301 moves away from the detection unit (antenna coil) of the switch body 211 installed on the door frame 302. At this time, the switch body 211 detects that the actuator 212 is not within a predetermined range relative to the switch body 211, i.e., that the door 301 is open, because communication between the detection unit and the RFID is not established.

[0116] Thus, the safety switches 210 are positioned to detect the open / closed state of the corresponding door 301.

[0117] If at least one of doors 301L and 301R (door 301L in this diagram) is open, the operation of the machine tool surrounded by the guard 300 is prohibited. On the other hand, if both doors 301L and 301R are closed, the operation of the machine tool surrounded by the guard 300 may be permitted (i.e., one of the conditions for permission to operate is met).

[0118] Thus, the safety switch 210 is a device for protective measures against moving equipment (mechanical hazards). In particular, the safety switch 210 is a type of safety protection that involves stopping. In this type, the operating area in which the hazard operates is partitioned, and the operation of the hazard is stopped when a state is detected where there is a possibility of human intrusion into the operating area, or when a human has entered. Specifically, in a safety system equipped with the safety switch 210, the hazard is stopped when the door 301 changes from a closed state to an open state.

[0119] In other words, as long as certain conditions are met, such as no human body entering the operating area, and this state is maintained by closing the door 301, the system is in a "safe state," an ON signal is output from the safety switch 210, and the hazard source is activated. On the other hand, when the door 301 moves from the "safe state" and the operating area is opened, an OFF signal is output from the safety switch 210, and the hazard source stops.

[0120] In the overall safety system, once an OFF signal is output from the safety switch 210, the hazard source will not reactivate even if the door 301 itself moves to the closed position, and will only reactivate when a separate reset signal is input. This is because once the door 301 is opened, even if the door 301 is subsequently closed, it is not possible to confirm that a human body has entered the operating area.

[0121] In addition to the safety functions described above, the safety switch 210 also has a locking mechanism to restrict the opening of the door 301.

[0122] For example, the safety switch 210 detects that the actuator 212 is within a predetermined range relative to the switch body 211 (i.e., the door 301 is closed) and, upon receiving a lock input from an external device (e.g., the aforementioned safety controller 230), drives the electromagnet of the switch body 211. At this time, the iron plate of the actuator 212 is magnetized. As a result, the opening of the door 301 is restricted by the attractive force between the electromagnet and the iron plate. The safety switch 210 may also be configured not to release the lock on the door 301 unless a specific signal is input from an external device. Furthermore, instead of the attraction between the electromagnet and the iron plate, the locking mechanism may utilize the engagement of a bolt and a pin.

[0123] If the safety switch 210 has a locking function, it is possible to prevent malfunctions such as the machine tool (mechanical hazard) stopping based on the OSSD output every time the user accidentally opens the door 301.

[0124] Thus, the above-mentioned locking function can be understood as an auxiliary function (=non-safety function) for maintaining the smooth operation of machine tools and the like. In other words, the safety function of the safety system is realized solely by the OSSD output of the safety switch 210.

[0125] <Safety switch (functional block)> Figure 7 shows the functional block of the safety switch 210. In this example of the safety switch 210, the switch body 211 comprises a control circuit 410, an input / output circuit 420, a switching device 430, an OSSD monitoring circuit 440, a power supply unit 450, a communication unit 460, a display unit 470, and an electromagnet 480. In this figure, the components (mainly components related to terminals) that are located on the rear side (back side) of the hinged switch body 211 are grouped together on the left side of the block. Also, the components that are located on the front side (front side) of the hinged switch body 211 are grouped together on the right side of the block.

[0126] The control circuit 410 (corresponding to the safety switch MCU) includes a first MCU 411 and a second MCU 412. The input / output circuit 420 includes a first safety input section 421, a second safety input section 422, an upstream communication section 423, and a downstream communication section 424. The switching device 430 includes a first safety output section 431 and a second safety output section 432. The power supply section 450 includes a power supply circuit 451 and a power supply monitoring circuit 452. The communication section 460 includes an antenna coil 463. The display section 470 includes an indicator light control section 471 and indicator lights 472.

[0127] Furthermore, in the safety switch 210 of this configuration example, the actuator 212 includes a communication unit 510. The communication unit 510 includes an antenna coil 511 and a response circuit 512.

[0128] The first MCU 411 and the second MCU 412 monitor each other by communicating with one another. The first MCU 411 and the second MCU 412 are connected to the antenna coil 463.

[0129] The first MCU 411 drives the antenna coil 463 and transmits a radio signal from the antenna coil 463 to the communication unit 510 (particularly the antenna coil 511) of the actuator 212. The communication unit 510 may be a radio tag (RF-ID tag).

[0130] The response circuit 512 operates using the induced current generated in the antenna coil 511 as its power source. The response circuit 512 also demodulates the radio signal received by the antenna coil 511 to obtain information, and then transmits a radio signal (response signal) via the antenna coil 511.

[0131] The first MCU 411 and the second MCU 412 each receive the radio signal (response signal) transmitted from the antenna coil 511 of the actuator 212 via the antenna coil 463.

[0132] The first MCU 411 includes a measurement unit 411a, a demodulation unit 411b, and a safety determination circuit 411c. The second MCU 412 includes a measurement unit 412a, a demodulation unit 412b, a safety determination circuit 412c, and a display control unit 412d.

[0133] Measurement units 411a and 412a each measure the strength of the radio signal (response signal) received via the antenna coil 463, and estimate the distance d between the antenna coil 463 of the switch body 211 and the antenna coil 511 of the actuator 212 (and consequently, the distance from the switch body 211 to the actuator 212) based on the measurement results. The antenna coil 463 functions as a detection unit that detects whether the actuator 212 is within a predetermined range relative to the switch body 211. Alternatively, the strength of the radio signal may be used directly to detect the position of the actuator 212 instead of the distance d between the coils.

[0134] Furthermore, the detection unit that detects whether the actuator 212 is within a predetermined range relative to the switch body 211 is not limited to the above method using the antenna coil 463. For example, a physical switch may be provided on the switch body 211, and the detection unit may employ a detection principle such that when the door is closed and the actuator 212 approaches the switch body 211, the physical switch is pressed by a protruding member or the like provided on the actuator 212.

[0135] The demodulation units 411b and 412b each demodulate the information carried by the radio signal (response signal) received via the antenna coil 463, and identify the actuator 212 based on this information. This information may include unique identification information (ID information).

[0136] The safety determination circuit 411c of the first MCU 411 determines whether the distance d between coils measured by the measurement unit 411a is less than or equal to the threshold dth, and transmits the determination result to the second MCU 412. Similarly, the safety determination circuit 412c of the second MCU 412 determines whether the distance d between coils measured by the measurement unit 412a is less than or equal to the threshold dth, and transmits the determination result to the first MCU 411. Then, if the determination result of the safety determination circuits 411c and 412c match that of the other (both determine that the distance d between coils is less than or equal to the threshold dth), they determine that the actuator 212 is within a predetermined range relative to the switch body 211 (door closed state).

[0137] In the input / output circuit 420, the first safety input section 421 and the second safety input section 422 are input circuits for cascading multiple safety switches 210 in serial order. For example, the first safety input section 421 and the second safety input section 422 are connected to the first safety output section 431 and the second safety output section 432 of another safety switch 210 located upstream, respectively.

[0138] The first MCU 411 is connected to the first safety input unit 421. When an ON signal is input through the first safety input unit 421, the first MCU 411 outputs a first safety output based on the proximity state of the actuator 212 (= door open / closed state) and the locked state of the electromagnet 480. The first MCU 411 controls unit 431. On the other hand, when an OFF signal is input through the first safety input unit 421, the first MCU 411 causes the first safety output unit 431 to output an OFF signal, regardless of the proximity state of the actuator 212 and the locked state of the electromagnet 480.

[0139] Similarly, the second MCU 412 is connected to the second safety input unit 422. When an ON signal is input through the second safety input unit 422, the second MCU 412 controls the second safety output unit 432 based on the proximity state of the actuator 212 and the locked state of the electromagnet 480. On the other hand, when an OFF signal is input through the second safety input unit 422, the second MCU 412 causes the second safety output unit 432 to output an OFF signal, without relying on the proximity state of the actuator 212 and the locked state of the electromagnet 480.

[0140] This allows multiple safety switches 210 to be cascaded. If any one of the safety switches 210 is not in a safe state, an OFF signal is output to an external device (e.g., a safety controller 230). Therefore, for example, if a fence surrounding a hazard is equipped with multiple doors, the hazard will not be able to operate unless all doors are in a safe state. On the other hand, if all of the safety switches 210 are in a safe state, an ON signal is output to the external device.

[0141] The upstream communication unit 423 is connected to another safety switch 210 located on the upstream side, and transmits upstream communication data (including lock input) and receives downstream communication data (including bundled AUX output data).

[0142] The downstream communication unit 424 is connected to another safety switch 210 or wiring-saving unit 250 located downstream, and transmits downstream communication data (including bundled AUX output data) and receives upstream communication data (including lock input).

[0143] For example, the control circuit 410 generates downstream communication data based on the communication data received via the upstream communication unit 423 (=communication data that bundles the upstream AUX outputs) and the state of the safety switch 210 itself, and outputs this data from the downstream communication unit 424.

[0144] The first safety output unit 431 and the second safety output unit 432 each output OSSD outputs (OSSD1_O and OSSD2_O) to another safety switch 210 or wiring-saving unit 250 located downstream.

[0145] For example, the control circuit 410 outputs OSSD outputs (OSSD1_O and OSSD2_O) from the first safety output unit 431 and the second safety output unit 432, respectively, based on the OSSD inputs (OSSD1_I and OSSD2_I) received via the first safety input unit 421 and the second safety input unit 422, and the proximity state of the actuator 212 (= detection result by the detection unit).

[0146] In the switching device 430, the first safety output section 431 and the second safety output section 432 may be configured as, for example, an open collector output circuit using a PNP type transistor. In this case, when the PNP type transistor is turned ON, the + side power supply is connected to the output terminal, so an ON signal (= high level) is output. On the other hand, when the PNP type transistor is turned OFF, the output terminal is grounded via a pull-down resistor, so an OFF signal (= low level) is output.

[0147] Furthermore, the first safety output section 431 and the second safety output section 432 can each be configured as open collector output circuits using NPN transistors. In this case, the output logic levels will be reversed from those described above. Specifically, the ON signal will be at a low level, and O The FF signal becomes high level.

[0148] The first safety output unit 431 and the second safety output unit 432 may each be connected to an OSSD monitoring circuit 440. The OSSD monitoring circuit 440 is connected to the first MCU 411 and the second MCU 412. The first MCU 411 monitors whether the operation of the second safety output unit 432 is normal through the OSSD monitoring circuit 440. The second MCU 412 monitors whether the operation of the first safety output unit 431 is normal through the OSSD monitoring circuit 440.

[0149] For example, the first safety output unit 431 and the second safety output unit 432 each periodically transition their output signals to OFF for a short period of time when outputting an ON signal. The OSSD monitoring circuit 440 determines that the OSSD is normal if it can detect a short period of OFF during the ON signal output period, and determines that the OSSD is not normal if it cannot detect a short period of OFF. When the OSSD is determined to be not normal, the OSSD outputs of the first safety output unit 431 and the second safety output unit 432 are transitioned to OFF. In this way, the OSSD monitoring circuit 440 detects a fault that has occurred in the switch body, and the result of detecting the fault is reflected in the OSSD outputs of the first safety output unit 431 and the second safety output unit 432.

[0150] If the ON signal persists, it is due to a short circuit between the output terminal and the positive power supply. In this case, safety judgment circuits 411c and 412c output control signals to the first safety output unit 431 and the second safety output unit 432, respectively, to output an OFF signal. As a result, the normal of the first safety output unit 431 and the second safety output unit 432 will output an OFF signal.

[0151] The external device (e.g., safety controller 230) can only permit the operation of the hazardous source when both the first safety output unit 431 and the second safety output unit 432 are outputting an ON signal. In other words, the external device will not permit the operation of the hazardous source when at least one of the first safety output unit 431 and the second safety output unit 432 is outputting an OFF signal. The external device is configured not to react to the minute OFF period in the aforementioned ON signal.

[0152] In the power supply unit 450, the power supply circuit 451 is a DC-DC converter that receives an input voltage VCC (e.g., DC +24V) and a ground voltage GND (e.g., 0V) from an external source and generates a desired output voltage VREG (e.g., DC +10V, +5V, or +3.3V). The power supply circuit 451 supplies power to all parts of the switch body 211 (i.e., all circuits that require power).

[0153] Incidentally, if the input voltage VCC or output voltage VREG is not within a predetermined range, the first MCU 411 and the second MCU 412 may not operate properly. Therefore, the power supply monitoring circuit 452 determines whether the input voltage VCC and output voltage VREG are within a predetermined range and outputs the determination result to the first safety output unit 431 and the second safety output unit 432.

[0154] When the first safety output unit 431 and the second safety output unit 432 receive a determination result indicating that the power supply circuit 451 is not operating normally, they each output an OFF signal, independent of the control signals output from the first MCU 411 and the second MCU 412, respectively.

[0155] Meanwhile, the first safety output unit 431 and the second safety output unit 432, upon receiving a determination result indicating that the power supply circuit 451 is operating normally, each output an ON signal or an OFF signal depending on the control signals output from the first MCU 411 and the second MCU 412, respectively. In this way, the power supply monitoring circuit 452 detects a power supply fault in the switch body 211, and the fault detection result is reflected in the OSSD output of the first safety output unit 431 and the second safety output unit 432.

[0156] The indicator light control unit 471, based on instructions from the control circuit 410 (for example, the indicator control unit 412d of the second MCU 412), turns the indicator light 472 (for example, a large indicator light) on / off or on green / on red depending on the proximity state of the actuator 212 (= door open / closed state) and the lock / unlock state of the electromagnet 480.

[0157] Furthermore, the indicator light control unit 471 turns the indicator lights 472 (for example, multiple small indicator lights) on / off or on / off in green / red depending on the OSSD output, INPUT signal, and lock / unlock state. The OSSD output mentioned above refers to the output signals of the first safety output unit 431 and the second safety output unit 432, respectively.

[0158] The electromagnet 480 generates a magnetic field by a drive current supplied from the control circuit 410 (for example, the second MCU 412). At this time, the iron plate (not shown) of the actuator 212, which is close to the switch body 211, is magnetized. As a result, the door lock is achieved by the attractive force between the electromagnet 480 and the iron plate.

[0159] <Terminal Function Switching> Incidentally, the safety switch 210 may be provided with a first operating mode in which the lock input and AUX output are input and output in parallel, similar to the conventional example described above (Figure 10), and a second operating mode in which the lock input and AUX output are input and output serially via a single communication line, similar to the first embodiment (Figure 1) and the second embodiment (Figure 2) described above.

[0160] As a means to realize the first and second operating modes described above, for example, the safety switch 210 is provided with a first terminal that can be switched as a lock input terminal or a downstream communication terminal, and a second terminal that can be switched as an AUX output terminal or an upstream communication terminal.

[0161] Furthermore, the safety switch 210 (especially the control circuit 410) may, for example, switch the first terminal and the second terminal from a first operating mode, where they are used as a lock input terminal and an AUX output terminal, to a second operating mode, where they are used as a downstream communication terminal and an upstream communication terminal, based on a switching signal input to the first terminal.

[0162] Furthermore, the wiring-saving unit 250 (especially the MCU250a) may, for example, send a switching signal indicating a specific pattern as upstream communication data instead of a lock input during startup.

[0163] The safety switch 210 in this configuration example can be marketed as a versatile model that supports both cascaded and non-cascaded connections.

[0164] <Signal Processing> Figure 8 shows an example of signal processing in the safety switch 210. Steps S101 to S108 in this figure can be understood as software processing performed by the control circuit 410 of the switch body 211.

[0165] In step S101, the distance d between the antenna coil 463 of the switch body 211 and the antenna coil 511 of the actuator 212 is measured.

[0166] In step S102, it is determined whether the distance d between coils measured in step S101 is within a predetermined range (less than or equal to the threshold dth). If the result is yes, the flow proceeds to step S103. On the other hand, if the result is no, the flow returns to step S101. Also, if the result is no in step S102, the display unit 470 may be illuminated red.

[0167] In step S103, the wireless signal (response signal) from the actuator 212 is demodulated, and the identification information (ID) of the actuator 212 is obtained.

[0168] In step S104, it is determined whether the ID obtained in step S103 matches the expected value. If the result is yes, the flow proceeds to step S105. On the other hand, if the result is no, the flow returns to the aforementioned step S101. Also, if the result is no in step S104, the display unit 470 may be illuminated red.

[0169] In step S105, it is determined whether the electromagnet 480 of the switch body 211 and the iron plate of the actuator 212 are in close contact. If the result is yes, the flow proceeds to step S106. On the other hand, if the result is no, the flow returns to the aforementioned step S101.

[0170] Figure 9 shows an example of the contact determination process in step S105, and from top to bottom, it depicts the current control signal for the electromagnet 480 and the test current flowing through the electromagnet 480 (without anchor plate / with anchor plate).

[0171] During the ON period of the current control signal (high-level period in this diagram), a test current is supplied to the electromagnet 480. The value of the test current is smaller than the value of the drive current supplied during locking and attraction. If a test current equal to the drive current used for locking and attraction is supplied, the door may become difficult to open even without a lock input, affecting usability. Therefore, it is desirable to supply a very small test current that does not generate any attraction force to perform contact detection.

[0172] In the contact detection process in step S105, the current value of the test current flowing through the electromagnet 480 is monitored. When the iron plate (anchor plate) is in close contact with the electromagnet 480, the inductance of the electromagnet 480 increases. Consequently, the response time of the test current (the time from when the current control signal is turned ON until the test current reaches a certain value) becomes longer.

[0173] Therefore, at the AD value check timing, a certain period of time after the current control signal is turned ON, it is determined whether the current value (AD value) of the test current exceeds the threshold.

[0174] For example, if the test current exceeds the threshold value at the AD value confirmation timing, it can be said that the inductance of electromagnet 480 is small and the response time is short. Therefore, it is determined that the iron plate is not in close contact. On the other hand, if the test current does not exceed the threshold value at the AD value confirmation timing, it can be said that the inductance of electromagnet 480 is large and the response time is long. Therefore, it is determined that the iron plate is in close contact.

[0175] Thus, in step S105, contact with the iron plate is determined by the change in the inductance of the electromagnet 480. Before a "yes" determination is made in step S105, the electromagnet 480 will not be driven even if a lock input is received. On the other hand, after a "yes" determination is made in step S105, the electromagnet 480 will be driven in response to the lock input.

[0176] If the electromagnet 480 is driven while it is not in close contact with the iron plate, it will attract magnetic foreign objects. Therefore, it is desirable to include the condition that the electromagnet 480 is in close contact with the iron plate as a driving condition for the electromagnet 480.

[0177] Returning to Figure 8, let's continue the flow explanation. In step S106, various input judgment processes are performed. Referring to this figure, in step S106, as the first input judgment, safety switch It is determined whether the lock input from the control device (such as the safety controller 230) that controls the switch 210 is ON or OFF. For safety switches that do not have a lock function (for example, the safety switch 210 (A4) in Figure 2 above), the first input determination is omitted.

[0178] In step S106, as a second input determination, it is determined whether or not all OSSD inputs from another safety switch 210 cascaded upstream are ON.

[0179] Furthermore, the second input determination described above only needs to be performed if multiple safety switches 210 are cascaded. The determination of whether or not a cascaded connection exists can be performed independently of the software processing of the control circuit 410 as shown in the flow chart of steps S101 to S108. For example, the determination of whether or not a cascaded connection exists may be performed at the determination processing timing included in steps S101 to S108 (e.g., steps S102, S104, and S105) or at predetermined time intervals.

[0180] Furthermore, the display unit 470 may perform display control according to the input judgment result in step S106. As an example of display control, if the lock input is ON and the safety input is OFF, the display unit 470 may light up orange. On the other hand, if the lock input is OFF and the safety input is ON, the display unit 470 may blink green. Also, if both the lock input and the safety input are OFF, the display unit 470 may blink orange.

[0181] In step S107, it is determined whether both the first and second input checks in step S106 are ON, or in other words, whether both the lock input and the OSSD input are ON. If the result is yes, the flow proceeds to step S108. On the other hand, if the result is no, the flow returns to step S107 and the above check process continues.

[0182] In step S108, an ON signal is output via the first safety output unit 431 and the second safety output unit 432. That is, the OSSD output is turned ON. Such a safety output is used for input determination processing in another safety switch 210 cascaded downstream. The indicator unit 470 may also be illuminated green to indicate that the OSSD output is ON.

[0183] Subsequently, the flow returns to step S101 to determine whether or not to maintain the state in which the safety output is ON. In this embodiment, the decisions in steps S101 and S106 affect the safety output. Therefore, in the flow for determining whether or not to maintain the state in which the safety output is ON, step S105 may be omitted.

[0184] <Summary> The various embodiments described above will be summarized below.

[0185] For example, a wiring unit disclosed herein has a safety switch having an actuator and a switch body for detecting the actuator, and a safety switch port having a power input section for receiving power, a pair of safety input terminals for receiving a first safety signal which is a pair of safety signals output by a first safety switch among the multiple safety switches connected in cascade, a pair of power output terminals for supplying power received via the power input section to the multiple safety switches, and a wiring unit communication terminal for bidirectional communication with the first safety switch, a safety output section internally connected to the pair of safety input terminals to pass through the first safety signal received via the pair of safety input terminals, and a safety switch among the multiple safety switches that can lock the movement of the actuator relative to the switch body in response to an instruction The system includes a lock instruction input unit that receives a lock instruction, an information output unit that outputs information indicating the status of each of the plurality of safety switches individually, and a wiring unit MCU that outputs information indicating the status of each of the plurality of safety switches individually based on information received from the plurality of safety switches via the wiring unit communication terminal, and outputs a lock input to the lockable safety switch to instruct locking based on the lock instruction received via the lock instruction input unit, wherein the safety output unit is internally connected to the pair of safety input terminals so that a fault can be detected by the fault detection function of the first safety switch (first configuration).

[0186] In addition, in the wiring unit according to the first configuration described above, the wiring unit MCU may be configured to be isolated from the safety output line including the safety input terminal and the safety output section (second configuration).

[0187] Furthermore, the wiring unit according to the second configuration described above may also include a safety signal monitoring unit that monitors the first safety signal sent to the safety output line and outputs the monitoring result to the wiring unit MCU, and the safety signal monitoring unit may be configured to include a transmitting unit that transmits a monitoring signal based on the first safety signal sent to the safety output line, and a receiving unit that receives the monitoring signal through isolated communication with the transmitting unit and outputs it to the wiring unit MCU (third configuration).

[0188] Furthermore, in the wiring unit according to the third configuration described above, the transmitting unit may be configured to transmit a non-electrical monitoring signal based on the first safety signal sent to the safety output line (fourth configuration).

[0189] Furthermore, the wiring unit according to the first configuration described above may also be configured to include a housing that accommodates the wiring unit MCU, and the safety switch port may be configured to include a connector provided on the housing (fifth configuration).

[0190] Furthermore, the wiring unit according to the first configuration described above may also be configured (sixth configuration) in which a housing for the wiring unit MCU and a cable extending outside the housing are provided, and the safety switch port is provided on a connector on the cable.

[0191] Furthermore, the wiring unit according to the first configuration described above may also be configured (seventh configuration) in which a housing for the wiring unit MCU is provided, and the housing is provided with a first safety switch port and a second safety switch port as safety switch ports, and a first lock instruction input unit that receives a lock instruction to instruct the lockable safety switch connected via the first safety switch port to lock, and a second lock instruction input unit that receives a lock instruction to instruct the lockable safety switch connected via the second safety switch port to lock.

[0192] Furthermore, the wiring unit according to the first configuration described above may be configured such that, when a plurality of the lockable safety switches are connected as the plurality of safety switches, the wiring unit MCU supplies the same lock input to each of the plurality of lockable safety switches (eighth configuration).

[0193] Furthermore, the wiring unit according to the first configuration described above may also be configured (the ninth configuration) to include a housing that houses the wiring unit MCU, and indicator lights provided in the housing that individually display the status of each of the plurality of safety switches based on information received from the plurality of safety switches via the wiring unit communication terminal.

[0194] Furthermore, the wiring unit according to the first configuration described above is housed in a casing that houses the wiring unit MCU. The configuration may also include an OSSD indicator light provided in the housing that displays the status of the first safety signal received by the safety input terminal included in the safety switch port (the 10th configuration).

[0195] Furthermore, the wiring unit according to the first configuration described above may also have a configuration (11th configuration) comprising a housing that accommodates the wiring unit MCU and a cable extending outside the housing as the safety output unit.

[0196] Furthermore, the wiring unit according to the first configuration described above may also have a configuration (12th configuration) comprising a housing that accommodates the wiring unit MCU and a cable extending outside the housing as the lock instruction input unit.

[0197] Furthermore, the wiring unit according to the first configuration described above may also have a configuration (13th configuration) comprising a housing that accommodates the wiring unit MCU and a cable extending outside the housing as the information output unit.

[0198] Furthermore, the wiring unit according to the first configuration described above may also have a configuration (14th configuration) comprising a housing that accommodates the wiring unit MCU and a cable extending outside the housing as the power input section.

[0199] Furthermore, the wiring unit according to the first configuration described above may also be configured such that at least one of the safety output unit, the lock instruction input unit, the information output unit, and the power input unit is configured as a terminal block (15th configuration).

[0200] Furthermore, for example, the serial cascade connector system disclosed herein comprises a first safety switch and a second safety switch, each having an actuator and a switch body for detecting the actuator, and a wiring unit to which the first safety switch and the second safety switch are connected in a cascade connection, wherein at least one of the first safety switch and the second safety switch is a lockable safety switch, each having a locking part capable of locking the movement of the actuator in response to a lock input, the first safety switch having a pair of first safety input terminals for receiving a second safety signal which is a pair of safety signals output by the second safety switch, a pair of first safety output terminals for outputting a first safety signal which is a pair of safety signals to the wiring unit, a first terminal for bidirectional communication with the second safety switch, a second terminal for bidirectional communication with the wiring unit, a detection unit for detecting that the actuator is within a predetermined range relative to the switch body, and outputting the first safety signal based on the second safety signal received via the first safety input terminals and the detection result by the detection unit, The wiring unit comprises a safety switch MCU that outputs information indicating the status of the first safety switch and the second safety switch via the second terminal based on information indicating the status of the second safety switch received via the first terminal, and a fault detection unit that detects a failure of the first safety switch, and the wiring unit has a safety switch port having a pair of safety input terminals that receive the first safety signal, a power input unit for receiving power, a pair of power output terminals for supplying the power received via the power input unit to the first safety switch and the second safety switch, and a wiring unit communication terminal for bidirectional communication with the first safety switch, a safety output unit internally connected to the pair of safety input terminals to pass through the first safety signal received via the safety input terminals, a lock instruction input unit that receives a lock instruction for locking the lockable safety switch, an information output unit for individually outputting information indicating the status of each of the plurality of safety switches, and information indicating the status of the first safety switch and information indicating the status of the second safety switch individually based on information received via the wiring unit communication terminal,In order to issue a lock command based on the lock command received via the lock command input unit, The system includes a wiring unit MCU that outputs a lock input to the lockable safety switch via the wiring unit communication terminal, and the safety output unit is internally connected to the pair of safety input terminals so that a fault can be detected by a fault detection unit in the first safety switch that receives the first safety signal output through from the safety output unit (16th configuration).

[0201] Furthermore, the serial cascade connector system according to the 16th configuration described above may be configured such that, when the wiring unit MCU receives the lock instruction via the lock instruction input unit, the lock input for driving the lock portion of the second safety switch, which is a lockable safety switch, is input to the second safety switch at a timing different from the timing at which the lock portion of the first safety switch, which is a lockable safety switch, is driven (17th configuration).

[0202] Furthermore, in the serial cascade connector system according to the 16th configuration described above, the wiring unit MCU may transmit a switching signal to the first safety switch via the wiring unit communication terminal when it is started up, and the first safety switch may, based on the switching signal, switch the operating modes of the two terminals, the first terminal and the second terminal, from a first operating mode in which one of the first and second terminals is used as a lock input terminal that accepts the lock input and the other is used as a status information output terminal that outputs information indicating the state of the first safety switch, to a second operating mode in which the first terminal is used as an upstream communication terminal for bidirectional communication with the second safety switch and the second terminal is used as a downstream communication terminal for bidirectional communication with the wiring unit (18th configuration).

[0203] <Other variations> Furthermore, the various technical features disclosed herein can be modified in various ways, in addition to the embodiments described above, without departing from the spirit of the technical creation. In other words, the embodiments described above should be considered in all respects to be illustrative and not restrictive, and the technical scope of the present invention should be defined by the claims and understood to include all modifications that fall within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0204] 100, 200 Serial Cascade Connector System 110, 210 Safety Switch 120, 220 Power Supply Units 130, 230 Safety Controller 140, 240 Non-Safety Controllers 211L, 211R Switch body 212L, 212R Actuators 250 Wiring-Saving Units 250a MCU 250b Lock Input Section 250C Voltage Regulator 250d OSSD Monitoring Unit 250e AUX output section 250f LED 251A, 251B Switch Connection Connectors 252A, 252B OSSD indicator light 253 Switch status indicator light 254 Setting switch 300 Guard 301L, 301R Door 302 Door frame 303L, 303R Support Members 410 Control circuit 411 First MCU 411a Measuring part 411b Demodulation section 411c Safety judgment circuit 412 Second MCU 412a Measuring part 412b Demodulation section 412c Safety Judgment Circuit 412d Display Control Unit 420 Input / Output Circuits 421 First safety input section 422 Second safety input section 423 Upstream Communications Department 424 Downstream Communications Department 430 Switching Devices 431 First safety output section 432 Second safety output section 440 OSSD monitoring circuit 450 Power supply section 451 Power supply circuit 452 Power supply monitoring circuit 460 Communications Department 463 Antenna coil 470 Display section 471 Indicator light control unit 472 Indicator light 480 Electromagnet 510 Communications Department 511 Antenna coil 512 Response Circuit Ports A and B CBL1~CBL10 Cables CNT1~CNT8 Connectors P11, P21 power supply terminal P12, P22 ground terminal P13, P23 OSSD output terminals P14, P24 OSSD output terminals P15, P25 OSSD input terminals P16, P26 OSSD input terminals P17 Lock Input Terminal P18 AUX output terminal P27 Downstream communication terminal P28 Upstream communication terminal P31 VCC pin P32 VCC_A pin P33 VCC_B pin P34 GND terminal P35 GND_A terminal P36 GND_B terminal P37 OSSD1_I_A terminal P38 OSSD2_I_A terminal P39 OSSD1_O_A terminal P40 OSSD2_O_A terminal P41 OSSD1_I_B terminal P42 OSSD2_I_B terminal P43 OSSD1_O_B terminal P44 OSSD2_O_B terminal P45 COM_A terminal P46 COM_B terminal P47 LOCK_A terminal P48 LOCK_B terminal P49(1)~P49(8) AUX1 terminal~AUX8 terminal TM1, TM2 Terminator

Claims

1. A wiring unit in which multiple safety switches, each having an actuator and a switch body for detecting the actuator, are connected in a cascaded configuration, A power input section for receiving power, A safety switch port having a pair of safety input terminals that receive a first safety signal, which is a pair of safety signals output by a first safety switch among a plurality of cascaded safety switches; a pair of power output terminals for supplying power received via the power input section to the plurality of safety switches; and a wiring unit communication terminal for bidirectional communication with the first safety switch, A safety output unit is internally connected to the pair of safety input terminals so as to pass through the first safety signal received via the pair of safety input terminals, A lock instruction input unit that receives a lock instruction to lock a safety switch among the plurality of safety switches that is capable of locking the movement of the actuator relative to the switch body in response to an instruction, An information output unit for individually outputting information indicating the status of each of the aforementioned multiple safety switches, The wiring unit MCU includes a wiring unit that, based on information received from the plurality of safety switches via the wiring unit communication terminal, individually outputs information indicating the status of each of the plurality of safety switches, and outputs a lock input to the lockable safety switch to instruct locking based on the lock instruction received via the lock instruction input unit, The safety output unit is a wiring unit that is internally connected to the pair of safety input terminals so that a fault can be detected by the fault detection function of the first safety switch.

2. The wiring unit MCU is isolated from the safety output line including the safety input terminal and the safety output section, according to claim 1.

3. The wiring unit according to claim 2, further comprising a safety signal monitoring unit that monitors the first safety signal sent to the safety output line and outputs the monitoring result to the wiring unit MCU, wherein the safety signal monitoring unit comprises a transmitting unit that transmits a monitoring signal based on the first safety signal sent to the safety output line, and a receiving unit that receives the monitoring signal through isolated communication with the transmitting unit and outputs it to the wiring unit MCU.

4. The wiring unit according to claim 3, wherein the transmitting unit transmits the non-electrical monitoring signal based on the first safety signal sent to the safety output line.

5. The enclosure comprises the aforementioned wiring unit MCU, The wiring unit according to claim 1, wherein the port for the safety switch is comprised of a connector provided on the housing.

6. A housing for the aforementioned wiring unit MCU, The enclosure includes a cable extending outside the enclosure, The wiring unit according to claim 1, wherein the port for the safety switch is comprised of a connector provided on the cable.

7. The enclosure comprises the aforementioned wiring unit MCU, The aforementioned housing, The first safety switch port and the second safety switch port, which serve as the safety switch ports, The lock instruction input unit is connected via the port for the first safety switch. The wiring unit according to claim 1, further comprising: a first lock instruction input unit that receives a lock instruction for instructing a lockable safety switch to lock; and a second lock instruction input unit that receives a lock instruction for instructing a lockable safety switch to lock, which is connected via a port for the second safety switch.

8. The wiring unit according to claim 1, wherein when a plurality of lockable safety switches are connected as the plurality of safety switches, the wiring unit MCU supplies the same lock input to each of the plurality of lockable safety switches.

9. A housing for the aforementioned wiring unit MCU, The wiring unit according to claim 1, further comprising: an indicator light provided in the housing, which individually displays the status of each of the plurality of safety switches based on information received from the plurality of safety switches via the wiring unit communication terminal.

10. A housing for the aforementioned wiring unit MCU, Wiring unit according to claim 1, comprising: an OSSD indicator light provided on the housing, which displays the status of the first safety signal received by the safety input terminal included in the safety switch port;

11. A housing for the aforementioned wiring unit MCU, The wiring unit according to claim 1, further comprising a cable extending outside the housing as the safety output unit.

12. A housing for the aforementioned wiring unit MCU, The wiring unit according to claim 1, further comprising a cable extending outside the housing as the lock instruction input unit.

13. A housing for the aforementioned wiring unit MCU, The wiring unit according to claim 1, further comprising a cable extending outside the housing as the information output unit.

14. A housing for the aforementioned wiring unit MCU, The wiring unit according to claim 1, further comprising a cable extending outside the housing as the power input section.

15. The wiring unit according to claim 1, wherein at least one of the safety output unit, the lock instruction input unit, the information output unit, and the power input unit is configured as a terminal block.

16. A first safety switch and a second safety switch, each having an actuator and a switch body that detects the actuator, A wiring unit in which the first safety switch and the second safety switch are connected in a cascade configuration, Equipped with, At least one of the first safety switch and the second safety switch is a lockable safety switch that includes a locking mechanism capable of locking the movement of the actuator in response to a lock input. The first safety switch is, A pair of first safety input terminals for receiving the second safety signal, which is a pair of safety signals output by the second safety switch, A pair of first safety signals, which are a pair of safety signals, are output to the aforementioned wiring unit. Safety output terminal and A first terminal for bidirectional communication with the second safety switch, A second terminal for bidirectional communication with the aforementioned wiring unit, A detection unit that detects whether the actuator is within a predetermined range relative to the switch body, A safety switch MCU that outputs the first safety signal based on the second safety signal received via the first safety input terminal and the detection result by the detection unit, and outputs information indicating the state of the first safety switch and the second safety switch via the second terminal based on information indicating the state of the second safety switch received via the first terminal, The system includes a fault detection unit that detects a malfunction in the first safety switch, The aforementioned wiring unit is A safety switch port having a pair of safety input terminals for receiving the first safety signal, a power input section for receiving power, a pair of power output terminals for supplying the power received via the power input section to the first safety switch and the second safety switch, and a wiring unit communication terminal for bidirectional communication with the first safety switch, A safety output unit is internally connected to the pair of safety input terminals so as to pass through the first safety signal received via the safety input terminals, A lock instruction input unit that receives a lock instruction to lock the lockable safety switch, An information output unit for individually outputting information indicating the status of each of the aforementioned multiple safety switches, The wiring unit MCU includes a wiring unit that, based on information received via the wiring unit communication terminal, outputs separately information indicating the state of the first safety switch and information indicating the state of the second safety switch, and outputs a lock input to the lockable safety switch via the wiring unit communication terminal for instructing locking based on the lock instruction received via the lock instruction input unit, A serial cascade connector system wherein the safety output unit is internally connected to the pair of safety input terminals so that a fault can be detected by a fault detection unit provided in the first safety switch, which receives the first safety signal that is output through from the safety output unit.

17. The serial cascade connector system according to claim 16, wherein when the wiring unit MCU receives the lock instruction via the lock instruction input unit, the lock input for driving the lock portion of the second safety switch, which is a lockable safety switch, is input to the second safety switch at a timing different from the timing at which the lock portion of the first safety switch, which is a lockable safety switch, is driven.

18. The wiring unit MCU transmits a switching signal to the first safety switch via the wiring unit communication terminal when it is started up. The serial cascade connector system according to claim 16, wherein the first safety switch switches the operating mode of the two terminals, the first terminal and the second terminal, based on the switching signal, from a first operating mode in which one of the first terminal and the second terminal is used as a lock input terminal for receiving the lock input and the other as a status information output terminal for outputting information indicating the state of the first safety switch, to a second operating mode in which the first terminal is used as an upstream communication terminal for bidirectional communication with the second safety switch and the second terminal is used as a downstream communication terminal for bidirectional communication with the wiring unit.

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