Switch system and switch

Abstract

To determine individually whether an actuator of each switch is brought close to a detection unit.SOLUTION: In a switch system, a controller and a plurality of switches are connected in an annular manner by signal lines, and a signal transmitted from the controller to a first switch, which is one of the plurality of switches, passes through the plurality of switches in sequence, and is returned from a second switch, which is one of the plurality of switches, to the controller. Each of the plurality of switches has an actuator, a detection unit that detects the proximity of the actuator, a receiving unit that receives a signal via a signal line, a control unit that causes the signal to include proximity information indicating whether the actuator is in proximity to the detection unit, and a transmission unit that transmits the signal with the proximity information included via the signal line. The signal that the controller receives from the second switch includes proximity information for each of the plurality of switches.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a switch system and a switch. [Background technology]

[0002] One method for connecting a controller to multiple switches is to connect multiple switches in series to the controller. For example, Patent Document 1 discloses connecting multiple non-contact door switches in series to a high-function unit. For example, in the non-contact door switch of Patent Document 1, a sensor unit attached to the fixed frame side of the door detects the approach or separation of an actuator attached to the door side that is opened or closed, that is, the opening and closing of the door. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4736793 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, when the sensor units of all the non-contact door switches detect the approach of an actuator, a signal of a predetermined pattern is input to the high-function unit, and when the sensor unit of any of the non-contact door switches does not detect the approach of an actuator, a signal of the predetermined pattern is not input to the high-function unit. Therefore, when the non-contact door switches are installed on the doors, it is possible to determine whether all the doors are closed or not, but it is not possible to determine the open / closed state of each door individually.

[0005] The present invention has been made in consideration of the above-mentioned situation, and its object is to provide a technology that can individually determine whether or not the actuator of each switch is in proximity to a detection unit. [Means for solving the problem]

[0006] A switch system according to the present disclosure includes a controller, a plurality of switches, and a signal line connecting the controller and the plurality of switches in a ring shape, wherein a signal transmitted from the controller to a first switch that is one of the plurality of switches passes through the plurality of switches in order and is returned to the controller from a second switch that is also one of the plurality of switches, wherein each of the plurality of switches includes an actuator, a detection unit that detects the proximity of the actuator, a receiving unit that receives the signal via the signal line, a control unit that includes proximity information indicative of whether the actuator is in proximity to the detection unit, and a transmitting unit that transmits the signal including the proximity information via the signal line, and the signal received by the controller from the second switch includes the proximity information of each of the plurality of switches.

[0007] The signal received by the controller includes proximity information indicating whether or not the actuator of each of the multiple switches is in proximity to the detection unit. The controller can determine whether or not the actuator of each of the multiple switches is in proximity to the detection unit by analyzing the received signal. By attaching multiple switches to multiple doors, respectively, the controller can determine the open / closed state of each door individually.

[0008] The proximity information for each of the plurality of switches may be included in a corresponding portion of the signal for each of the plurality of switches. By analyzing the portions corresponding to each of the multiple switches, it is possible to individually determine whether or not the actuator is in proximity to the detection portion for each of the multiple switches.

[0009] In a switch system according to the present disclosure, the signal may have a first value and a second value, and the control unit of the plurality of switches may set the portions of the signal corresponding to each of the plurality of switches to the first value when the actuator is in proximity to the detection unit, and set the portions of the signal corresponding to each of the plurality of switches to the second value when the actuator is not in proximity to the detection unit. The controller determines that the actuator is in proximity to the detection unit when the portions of the received signal corresponding to each of the plurality of switches are the first value. The controller determines that the actuator is not in proximity to the detection unit when the portions of the received signal corresponding to each of the plurality of switches are the second value.

[0010] In the switch system according to the present disclosure, the first value may be a high level and the second value may be a low level. The controller determines that the actuator is close to the detection unit when the portions of the received signal corresponding to each of the multiple switches are at a high level, and determines that the actuator is not close to the detection unit when the portions of the received signal corresponding to each of the multiple switches are at a low level. The first value may be a low level and the second value may be a high level. The controller determines that the actuator is close to the detection unit when the portions of the received signal corresponding to each of the multiple switches are at a low level. The controller determines that the actuator is not close to the detection unit when the portions of the received signal corresponding to each of the multiple switches are at a high level.

[0011] In a switch system according to the present disclosure, the controller may include request information for requesting status information indicating a state of the switch in the signal to be transmitted to the first switch, the control units of the multiple switches may determine whether the status information is requested based on the request information included in the signal, and if the status information is requested, may include the status information in the signal, and the signal received by the controller from the second switch may include the status information of at least one of the multiple switches. The controller may obtain the status information of at least one of the multiple switches by analyzing the received signal.

[0012] In a switch system according to the present disclosure, the control unit of the plurality of switches may determine whether the signal includes a predetermined pattern, and if the signal includes the predetermined pattern, select a first mode, and if the signal does not include the predetermined pattern, select a second mode, and in the first mode, the control unit includes the proximity information in the signal, and the transmission unit transmits the signal including the proximity information via the signal line, and in the second mode, when the signal is in a first state and the actuator is close to the detection unit, the control unit maintains the signal in the first state, and the transmission unit transmits the signal in the first state via the signal line, and in the second mode, when the signal is in the first state and the actuator is not close to the detection unit, the control unit changes the signal to a second state, and the transmission unit transmits the signal in the second state via the signal line, and in the second mode, when the signal is in the second state, the control unit maintains the signal in the second state, and the transmission unit transmits the signal in the second state via the signal line. The controller can individually determine whether or not the actuator of each of the multiple switches is close to the detection unit by analyzing the received signal. Also, the controller can determine whether the actuator of all of the switches is close to the detection unit or whether the actuator of at least one of the multiple switches is not close to the detection unit by analyzing the received signal.

[0013] In the switch system according to the present disclosure, the first state may be an on state and the second state may be an off state. In the switch system according to the present disclosure, the first state may be an off state and the second state may be an on state. In the switch system according to the present disclosure, the controller may transmit the signal not including the predetermined pattern to the first switch before transmitting the signal including the predetermined pattern to the first switch. First, the controller transmits a signal not including the predetermined pattern to the first switch and receives a signal in the first state or the second state from the second switch. The controller can determine whether or not the actuators of all the switches are in proximity to the detection unit by analyzing the signal in the first state or the second state. Next, the controller transmits a signal including the predetermined pattern to the first switch and receives a signal including proximity information from the second switch. The controller can determine whether or not the actuators of the multiple switches are in proximity to the detection unit by analyzing the signal including proximity information.

[0014] In a switch system according to the present disclosure, the signal line may include a first signal line and a second signal line, the controller may transmit the signal including the predetermined pattern to the first switch via the first signal line and the signal not including the predetermined pattern to the first switch via the second signal line, and the transmitters of the plurality of switches may transmit the signal including the proximity information via the first signal line and the signal in the first state or the second state via the second signal line. The switch according to the present disclosure may be one of the plurality of switches in the switch system and connected to the controller by the signal line. The switch according to the present disclosure may be one of the plurality of switches in the switch system and connected to other two of the plurality of switches by the signal lines.

[0015] A switch according to the present disclosure is a switch in a switch system in which a signal transmitted from a controller to one of a plurality of switches via a signal line connecting the controller and the plurality of switches in a ring shape passes through the plurality of switches in order and is returned from one of the plurality of switches to the controller, the switch comprising an actuator, a detection unit that detects the proximity of the actuator, a reception unit that receives the signal via the signal line, a control unit that determines whether the signal includes a predetermined pattern, and a transmission unit that transmits the signal via the signal line, wherein the control unit selects a first mode when the signal includes the predetermined pattern, and selects a second mode when the signal does not include the predetermined pattern, and in the first mode, the control unit detects whether the actuator is in proximity to the detection unit and returns to the controller. the signal includes proximity information indicating whether the actuator is in a first state or not, and the transmitter transmits the signal including the proximity information via the signal line; in the second mode, when the signal is in a first state and the actuator is in proximity to the detection unit, the control unit maintains the signal in the first state, and the transmitter transmits the signal in the first state via the signal line; in the second mode, when the signal is in the first state and the actuator is not in proximity to the detection unit, the control unit changes the signal to a second state, and the transmitter transmits the signal in the second state via the signal line; in the second mode, when the signal is in the second state, the control unit maintains the signal in the second state, and the transmitter transmits the signal in the second state via the signal line.

[0016] The control unit selects the first mode or the second mode depending on whether the received signal includes a predetermined pattern. The controller transmits a signal including the predetermined pattern to one of the multiple switches, and receives a signal including proximity information from one of the multiple switches. The controller can individually determine whether or not the actuator is in proximity to the detection unit for each of the multiple switches by analyzing the signal including proximity information. The controller transmits a signal not including the predetermined pattern to one of the multiple switches, and receives a signal including proximity information from one of the multiple switches. The controller receives a signal from one of the switches that is in a first state or a second state. By analyzing the signal that is in the first state or the second state, the controller can determine whether the actuators of all of the switches are in proximity to the sensing portion. Effect of the Invention

[0017] According to the present invention, it is possible to provide a technique that can individually determine whether or not an actuating body of each switch is in proximity to a detection unit. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a block diagram illustrating a schematic configuration of a switch system. [Diagram 2] FIG. 2 is an explanatory diagram of the communication protocol at the time of startup. [Diagram 3] FIG. 3 is an explanatory diagram of a communication protocol in normal operation. [Figure 4] FIG. 4 is an explanatory diagram of a communication protocol for acquiring status information. [Diagram 5] FIG. 5 is an explanatory diagram of the functions of the function blocks. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] <Application Examples> An application example of the switch system will be described with reference to FIG. 1. FIG. 1 is a block diagram showing a schematic configuration of the switch system. The switch system includes a controller 1, a plurality of switches 2, and signal lines 3 and 4 that connect the controller 1 and the plurality of switches 2 in a ring shape. The switches 2 are, for example, non-contact switches (non-contact switches). FIG. 1 shows an example of a configuration in which the switch system includes three switches 2 (2A, 2B, and 2C), but the number of switches 2 can be increased or decreased. The switch system may include two switches 2, or may include four or more switches 2.

[0020] The controller 1 and the multiple switches 2 are connected in a ring shape by signal lines 3 and 4. The controller 1 and switch 2A are connected by signal lines 3A and 4A, and the switch 2A and switch 2B are connected by signal lines 3B and 4B. Furthermore, the switch 2B and switch 2C are connected by signal lines 3C and 4C, and the switch 2C and the controller 1 are connected by signal lines 3D and 4D. In this manner, the switch 2A (one of the multiple switches 2) is connected to the controller 1 by signal lines 3A and 4A, and the switch 2C (one of the multiple switches 2) is connected to the controller 1 by signal lines 3D and 4D. Furthermore, the switch 2B (one of the multiple switches 2) is connected to the switches 2A and 2C (the other two of the multiple switches 2) by signal lines 3B, 3C, 4B, and 4C.

[0021] The controller 1 is an industrial control device such as a programmable logic controller that executes logic calculation processing and input / output control processing. The controller 1 may be a safety controller that ensures high safety and reliability by executing a self-diagnosis process for safety.

[0022] The controller 1 includes a control unit 11 that generates a pulse signal of a predetermined pattern, a transmission unit 12 that transmits the pulse signal, and a reception unit 13 that receives the pulse signal. The transmission unit 12 transmits a pulse signal to a switch 2A (first switch) that is one of the multiple switches 2 via signal lines 3A and 4A. The reception unit 13 receives a pulse signal from a switch 2C (second switch) that is one of the multiple switches 2 via signal lines 3D and 4D, processes the pulse signal, and transmits it to the control unit 11. A pulse signal transmitted from the controller 1 to one of the multiple switches 2 passes between the multiple switches 2 in order, and is returned from one of the multiple switches 2 to the controller 1. The pulse signal transmitted from the controller 1 or the upstream switch 2 is received by the downstream switch 2. Then, the controller 1 receives a pulse signal from one of the multiple switches 2. The pulse signal is an example of a signal.

[0023] The switch 2 is, for example, a door switch of a safety door for entering and exiting a work area partitioned by a safety fence or a wall around a mechanical equipment such as an industrial robot. Each of the multiple switches 2 includes an actuator 20 and a sensor unit 21. In the configuration example shown in FIG. 1, the switch 2A includes an actuator 20A and a sensor unit 21A, the switch 2B includes an actuator 20B and a sensor unit 21B, and the switch 2C includes an actuator 20C and a sensor unit 21C. The actuator 20 is, for example, an actuator attached to the door side to be opened or closed. The sensor unit 21 is, for example, attached to the fixed frame side of the door and detects the separation and approach of the actuator 20, that is, the opening and closing of the door. By attaching the switches 2A to 2C to multiple doors, the switch system shown in FIG. 1 can be used as a door switch system for detecting the opening and closing of the door. The sensor unit 21 includes a sensing unit 22 as a detection unit that detects the proximity of the actuator 20, a receiving unit 23 that receives a pulse signal, a transmitting unit 24 that transmits the pulse signal, a control unit 25 that performs various controls, and a display unit 26 that performs a specified display.

[0024] The sensing unit 22 detects the approach of the actuator 20 when the distance between the actuator 20 and the sensing unit 22 is equal to or less than a certain value. When the sensing unit 22 detects the approach of the actuator 20, it transmits a detection signal to the control unit 25, and when the sensing unit 22 no longer detects the approach of the actuator 20, it stops transmitting the detection signal to the control unit 25. The control unit 25 controls each part of the switch 2, processes signals, performs calculations, etc. The control unit 25 analyzes the pulse signal transmitted from the receiving unit 23.

[0025] The receiving unit 23A, the transmitting unit 24A, the control unit 25A, and the display unit 26A of the switch 2A will be described. The receiving unit 23A receives a pulse signal from the controller 1 via the signal lines 3A and 4A, processes the pulse signal, and transmits it to the control unit 25A. The control unit 25A judges whether or not the received pulse signal includes a predetermined pattern. If the received pulse signal includes a predetermined pattern, the control unit 25A selects the communication mode (first mode) and generates a pulse signal including proximity information indicating whether or not the actuating body 20A is in proximity to the sensing unit 22A. Thus, in the communication mode, the control unit 25A includes the proximity information indicating whether or not the actuating body 20A is in proximity to the sensing unit 22A in the pulse signal. The transmitting unit 24A transmits the pulse signal including the proximity information to the switch 2B via the signal lines 3B and 4B under the control of the control unit 25A. The display unit 26A displays information indicating that the actuating body 20A is close to the sensing unit 22A or information indicating that the actuating body 20A is not close to the sensing unit 22A. The display unit 26A may display the open / closed state of the door to which the switch 2A is attached.

[0026] The receiving unit 23B, the transmitting unit 24B, the control unit 25B, and the display unit 26B of the switch 2B will be described. The receiving unit 23B receives a pulse signal from the switch 2A via the signal lines 3B and 4B, processes the pulse signal, and transmits it to the control unit 25B. The control unit 25B determines whether the received pulse signal includes a predetermined pattern. If the received pulse signal includes a predetermined pattern, the control unit 25B selects the communication mode. The pulse signal received from the switch 2A includes the proximity information of the switch 2A. The control unit 25B generates a pulse signal including the proximity information of the switch 2A and the proximity information indicating whether the actuating body 20B is in proximity to the sensing unit 22B. In this way, in the communication mode, the control unit 25B causes the proximity information of the switch 2A and the proximity information indicating whether the actuating body 20B is in proximity to the sensing unit 22B to be included in the pulse signal. The transmitter 24B transmits a pulse signal including proximity information to one of the multiple switches 2 (switch 2C) via the signal lines 3C and 4C under the control of the controller 25B. The display unit 26B displays information indicating that the actuating body 20B is in proximity to the sensing unit 22B or information indicating that the actuating body 20B is not in proximity to the sensing unit 22B. The display unit 26B displays information indicating that the door to which the switch 2B is attached is opened or closed. The closed state may be displayed.

[0027] The receiving unit 23C, the transmitting unit 24C, the control unit 25C, and the display unit 26C of the switch 2C will be described. The receiving unit 23C receives a pulse signal from the switch 2B via the signal lines 3C and 4C, processes the pulse signal, and transmits it to the control unit 25C. The control unit 25C determines whether the received pulse signal includes a predetermined pattern. If the received pulse signal includes a predetermined pattern, the control unit 25C selects the communication mode. The pulse signal received from the switch 2B includes the proximity information of the switch 2A and the proximity information of the switch 2B. The control unit 25C generates a pulse signal including the proximity information of the switch 2A, the proximity information of the switch 2B, and the proximity information indicating whether the actuating body 20C is in proximity to the sensing unit 22C. In this way, in the communication mode, the control unit 25C causes the proximity information of the switch 2A, the proximity information of the switch 2B, and the proximity information indicating whether the actuating body 20C is in proximity to the sensing unit 22C to be included in the pulse signal. The transmitter 24C transmits a pulse signal including the proximity information to the controller 1 via the signal lines 3D and 4D under the control of the controller 25C. The display unit 26C displays information indicating that the actuating body 20C is in proximity to the sensing unit 22C or information indicating that the actuating body 20C is not in proximity to the sensing unit 22C. The display unit 26C may display the open / closed state of the door to which the switch 2C is attached.

[0028] The pulse signal received from switch 2C includes proximity information of switch 2A, proximity information of switch 2B, and proximity information of switch 2C. By analyzing the pulse signal received from switch 2C, controller 1 can individually determine whether or not actuating body 20A is close to sensing unit 22A, whether or not actuating body 20B is close to sensing unit 22B, and whether or not actuating body 20C is close to sensing unit 22C. Furthermore, by attaching switches 2A to 2C to multiple doors, respectively, controller 1 can individually determine the open / closed state of each door.

[0029] 1 shows an example in which signal lines 3 and 4 are used, but only one of signal line 3 and signal line 4 may be used. Also, signal line 3 may be used as a first signal line for transmitting a pulse signal, and signal line 4 may be used as a second signal line for transmitting a digital I / O signal (on / off signal). The on / off signal is one example of a signal.

[0030] A case will be described in which signal line 3 is used as a first signal line for transmitting a pulse signal, and signal line 4 is used as a second signal line for transmitting a digital I / O signal. Transmitter 12 of controller 1 transmits a pulse signal including a predetermined pattern to switch 2A via signal line 3A, and transmits a digital I / O signal not including a predetermined pattern to switch 2A via signal line 4A. When signal line 3 is used as the first signal line for transmitting a pulse signal, the operations of controller 1 and multiple switches 2 are as described above, and therefore details will be omitted.

[0031] A case where the signal line 4 is used as the second signal line for transmitting the digital I / O signal will be described. The controller 1 transmits an on signal as the digital I / O signal to the switch 2A. That is, the controller 1 transmits an on-off signal in the on state to the switch 2A. The on state is an example of the first state, and the off state is an example of the second state. The relationship between on and off may be reversed. The controller 1 may transmit an on-off signal in the off state to the switch 2A. The on state is an example of the second state, and the off state is an example of the first state. Similarly, the relationship between on and off may be reversed for the operations of the switches 2A to 2C described below. The receiver 23A of the switch 2A receives the digital I / O signal from the controller 1 via the signal line 4A, processes the digital I / O signal, and transmits it to the control unit 25A.

[0032] The control unit 25A determines whether the received digital I / O signal includes a predetermined pattern. If the received digital I / O signal does not include the predetermined pattern, the control unit 25A selects the digital I / O mode (second mode). Since the digital I / O signal does not include the predetermined pattern, the control unit 25A selects the digital I / O mode. In the digital I / O mode, if the digital I / O signal is in the ON state and the actuator 20A is close to the sensing unit 22A, the control unit 25A maintains the digital I / O signal in the ON state. The transmission unit 24A transmits the digital I / O signal in the ON state to the switch 2B via the signal line 4B under the control of the control unit 25A. In the digital I / O mode, if the digital I / O signal is in the ON state and the actuator 20A is not close to the sensing unit 22A, the control unit 25A changes the digital I / O signal to the OFF state. The transmitter 24A transmits a digital I / O signal in the OFF state to the switch 2B via the signal line 4B in accordance with the control of the controller 25A. In the digital I / O mode, when the digital I / O signal is in the OFF state, the controller 25A maintains the digital I / O signal in the OFF state. The transmitter 24A transmits a digital I / O signal in the OFF state to the switch 2B via the signal line 4B in accordance with the control of the controller 25A.

[0033] The receiving unit 23B of the switch 2B receives the digital I / O signal from the switch 2A via the signal line 4B, processes the digital I / O signal, and transmits it to the control unit 25B. The control unit 25B determines whether the received digital I / O signal contains a predetermined pattern. Since the digital I / O signal does not contain a predetermined pattern, the control unit 25B selects the digital I / O mode. In the digital I / O mode, when the digital I / O signal is in the ON state and the actuation body 20B is close to the sensing unit 22B, the control unit 25B maintains the digital I / O signal in the ON state. The transmitting unit 24B transmits the digital I / O signal in the ON state to the switch 2C via the signal line 4C under the control of the control unit 25B. In the digital I / O mode, when the digital I / O signal is in the ON state and the actuation body 20B is not close to the sensing unit 22B, the control unit 25B changes the digital I / O signal to the OFF state. The transmitter 24B transmits a digital I / O signal in the OFF state to the switch 2C via the signal line 4C in accordance with the control of the controller 25B. In the digital I / O mode, when the digital I / O signal is in the OFF state, the controller 25B maintains the digital I / O signal in the OFF state. The transmitter 24B transmits a digital I / O signal in the OFF state to the switch 2C via the signal line 4C in accordance with the control of the controller 25B.

[0034] After the same process as for switch 2B is performed for switch 2C, the transmitting unit 24C transmits a digital I / O signal in an ON or OFF state to the controller 1 via the signal line 4D under the control of the control unit 25C. The controller 1 determines whether the digital I / O signal received from switch 2C is in an ON or OFF state. If the digital I / O signal is in an ON state, the controller 1 determines that the actuators 20 of all the switches 2 are in proximity to the sensing unit 22. If the digital I / O signal is in an OFF state, the controller 1 determines that at least one actuator 20 of the multiple switches 2 is not in proximity to the sensing unit 22.

[0035] By analyzing the digital I / O signal received from the switch 2C, the controller 1 can determine whether the actuators 20 of all the switches 2 are in proximity to the sensing unit 22, or whether the actuators 20 of at least one of the multiple switches 2 are not in proximity to the sensing unit 22. Furthermore, by attaching the switches 2A to 2C to multiple doors, respectively, the controller 1 can determine whether all the doors are closed, or whether at least one of the multiple doors is open.

[0036] When the controller 1 determines whether each door is open or closed, the controller 1 transmits a pulse signal including a predetermined pattern to the switch 2A and receives a pulse signal including proximity information from the switch 2C. The controller 1 can individually determine whether the actuator 20 of each of the multiple switches 2 is in proximity to the sensing unit 22 by analyzing the signal including the proximity information. Therefore, the controller 1 can individually determine the open / closed state of each door by analyzing the pulse signal including the proximity information. When determining whether all the doors are closed, the controller 1 transmits a digital I / O signal not including a predetermined pattern to the switch 2A and receives a digital I / O signal in an on state or an off state from the switch 2C. The controller 1 can determine whether the actuator 20 of each of the switches 2 is in proximity to the sensing unit 22 by analyzing the digital I / O signal in an on state or an off state. Therefore, the controller 1 can determine whether all the doors are closed.

[0037] The processing time for each switch 2 to process a pulse signal is longer than the processing time for each switch 2 to process a digital I / O signal. When the controller 1 simultaneously performs a process of transmitting a pulse signal to the switch 2A and a process of transmitting a digital I / O signal to the switch 2A, the controller 1 receives the digital I / O signal before receiving a pulse signal from the switch 2C. The controller 1 may transmit a digital I / O signal not including a predetermined pattern to the switch 2A before transmitting a pulse signal including a predetermined pattern to the switch 2A. First, the controller 1 transmits a digital I / O signal not including a predetermined pattern to the switch 2A, and receives a digital I / O signal in an on state or an off state from the switch 2C, thereby making it possible to determine whether all the doors are closed or not. Therefore, safety control such as operation permission control and operation stop control for the machinery and equipment can be performed quickly. Next, the controller 1 transmits a pulse signal including a predetermined pattern to the switch 2A, and receives a pulse signal including proximity information from the switch 2C, thereby making it possible to individually determine the open / closed state of each door. In this way, by performing safety control using the signal line 4 as a second signal line for transmitting digital I / O signals, the response process of the entire safety system is improved.

[0038] <Device configuration> The configurations of the controller 1 and the switches 2 will be described with reference to FIG. 1. The controller 1 monitors the multiple switches 2 by transmitting a pulse signal to one of the multiple switches 2 and receiving a pulse signal from one of the multiple switches 2. As shown in FIG. 1, the controller 1 and the multiple switches 2 are connected in a ring shape. That is, the controller 1 and the multiple switches 2 are connected in series. For example, when the controller 1 and each switch 2 are directly connected, the controller 1 needs to have terminals for the number of connected switches 2. In the system configuration of this embodiment, the controller 1 and the multiple switches 2 are connected in series, so that the number of terminals of the controller 1 can be reduced.

[0039] The controller 1 performs safety control by analyzing the pulse signal received from the switch 2. The safety control by the controller 1 in the case where the switches 2A to 2C are attached to a plurality of doors will be described.

[0040] First, a case will be described in which the pulse signal received by the controller 1 from the switch 2C includes information indicating that the actuator 20A is close to the sensing unit 22A, information indicating that the actuator 20B is close to the sensing unit 22B, and information indicating that the actuator 20C is close to the sensing unit 22C. In this case, the controller 1 determines that all of the multiple doors are closed, and transmits an operation permission signal to machinery and equipment such as an industrial robot.

[0041] Next, the controller 1 receives a pulse signal from the switch 2C, and the actuator 20A is actuated by the sensor. A case will be described in which the information includes information indicating that actuating body 20C is close to sensing unit 22A, information indicating that actuating body 20B is close to sensing unit 22B, and information indicating that actuating body 20C is not close to sensing unit 22C. In this case, controller 1 determines that the door to which switch 2A is attached and the door to which switch 2B is attached are closed, determines that the door to which switch 2C is attached is open, and transmits an operation stop signal to the mechanical equipment.

[0042] The control unit 11 controls each part of the controller 1, processes signals, performs calculations, etc. The control unit 11 may be configured by a computer having, for example, an MPU or CPU (processor), RAM, a non-volatile storage device (e.g., ROM, flash memory, etc.). The form of the computer is not important. All or part of the functions provided by the control unit 11 may be configured by a circuit such as an ASIC or FPGA. The control unit 11 loads a communication program stored in the storage device into the RAM, and executes data communication with multiple switches 2 in accordance with a predetermined communication protocol.

[0043] The switch 2 may be a non-contact switch of a magnetic detection type, or may be a non-contact switch of an electromagnetic induction type. In the magnetic detection type, the sensing unit 22 detects the magnetism emitted from the actuator 20, and the sensing unit 22 detects the approach and separation of the actuator 20. In the electromagnetic induction type, the sensing unit 22 detects the presence of the actuator 20 based on a change in the degree of electromagnetic coupling, and detects the approach and separation of the actuator 20. The receiving unit 23 and the transmitting unit 24 of the switch 2 may perform a self-diagnosis process. The self-diagnosis process is, for example, a process of diagnosing whether or not there is an abnormality in the own unit. If there is an abnormality in the own unit, the receiving unit 23 and the transmitting unit 24 communicate to the control unit 25 that there is an abnormality in the own unit.

[0044] The control unit 25 of the switch 2 controls each unit of the switch 2, processes signals, performs arithmetic processing, etc. The control unit 25 may be configured by a computer having, for example, an MPU or a CPU (processor), RAM, a non-volatile storage device (e.g., ROM, flash memory, etc.). The form of the computer is not important. The control unit 25 may have multiple MPUs or multiple CPUs, and may perform mutual monitoring by multiple MPUs or multiple CPUs. All or part of the functions provided by the control unit 25 may be configured by a circuit such as an ASIC or FPGA.

[0045] <Communication protocol> The communication protocol employed by the switch system will now be described. First, the communication protocol at startup will be described with reference to FIG. 2. At startup, for example, the controller 1 and multiple switches 2 are connected and the controller 1 and multiple switches 2 are powered on while startup processing is being performed, or a predetermined time after startup processing. (A-1) in FIG. 2 is an example of the format of the communication protocol at startup. (A-2) in FIG. 2 is an example of the waveform (communication waveform) of the signal received by switch 2B at startup. As shown in FIG. 2, the start of the data contains information indicating the start of data transmission (start section), and the end of the data contains data transmission start information (start section). The type section is information for determining whether the startup mode or the normal mode is selected. In FIG. 2, since the type section in the pulse signal is at a high level, switch 2B recognizes that the current mode is the startup mode.

[0046] The ID setting data section is information for determining the ID numbers of the multiple switches 2. For switch 2, the number corresponding to the high level part of the ID setting data is its own ID. In Figure 2, the second part of the ID setting data is a high-level Since the switch 2B is a 10GbE switch, the switch 2B recognizes that its own ID number is “2”. The data length of the ID setting data section is fixed and is the maximum allowable connection length for the switch 2 in the system. Depends on the number of units.

[0047] The switch 2B continues to output a pulse signal indicating that the ID number is indefinite, with all of the ID setting data sections being at a low level, until it receives a pulse signal including a start section from the switch 2A. The control unit 25B of the switch 2B recognizes that the type portion of the pulse signal is at a high level. The control unit 25B of the switch 2B changes the second portion of the ID setting data portion of the pulse signal to a low level. Then, the third part of the ID setting data of the pulse signal is changed to High level. The transmission section 24B of the switch 2B transmits a pulse including the start section and the stop section shown in FIG. 2, the pulse signal is sent to the switch 2C. As shown in FIG. The error section is information used when an error occurs. When an abnormality occurs in switch 2, it changes the error part of the pulse signal from low level to The parity section is a command used for error detection. For example, each switch 2 detects an error in the received pulse signal, and when an error is detected in the received pulse signal, it changes the error section of the pulse signal from Low level to High level. To transform.

[0048] Switch 2C, which has received a pulse signal from switch 2B, changes the third portion of the ID setting data section of the pulse signal to low level, changes the fourth portion of the ID setting data section of the pulse signal to high level, and then transmits the pulse signal to controller 1. In this way, each switch 2 that has received a pulse signal changes its own ID setting data section of the pulse signal. The part of the pulse signal that corresponds to the ID number is changed to low level. After changing the part corresponding to the ID number of the subsequent switch (downstream switch) to High level, a pulse signal is transmitted.

[0049] The controller 1 receives a pulse signal from the switch 2C and sets the Hi bit in the ID setting data section. Determine whether the gh level part corresponds to the number of connected devices of switch 2 plus 1. The high level part of the ID setting data part of the pulse signal corresponds to the number of connected devices of switch 2. If the number does not correspond to the number with 1 added, the controller 1 judges that the communication is abnormal and transmits an operation stop signal to the machinery and equipment. Also, if the type part of the pulse signal received from the switch 2C is at a low level, or if the error part of the pulse signal received from the switch 2C is at a high level, the controller 1 judges that the communication or the switch 2 is abnormal. It determines that an abnormality has occurred and sends a signal to the machinery to stop operation.

[0050] Next, the communication protocol in normal mode will be described with reference to Fig. 3. The normal mode is, for example, a period after communication according to the communication protocol at startup is executed between the controller 1 and the multiple switches 2. (B-1) of Fig. 3 is an example of the format of the communication protocol in normal mode. (B-2) of Fig. 3 is an example of the waveform of a signal received by the controller 1 in normal mode. As shown in (B-2) of Fig. 3, in normal mode, the type portion of the pulse signal is set to low level.

[0051] In normal mode, each switch 2 uses its own ID in the open / close data section of the pulse signal. The proximity information is included in the part corresponding to the number, and the parity part is updated, and then a pulse signal is sent to the subsequent switch 2 or controller 1. The data in the open / close data part of the pulse signal is The data length is fixed and depends on the maximum number of switches 2 that can be connected in the system. As in the startup mode, when an abnormality occurs in each switch 2, the error portion of the pulse signal is changed from low level to high level. 2 detects errors in the received pulse signal, and if an error is detected in the received pulse signal, changes the error portion of the pulse signal from low level to high level.

[0052] 3 includes information indicating that the actuator 20 of the first switch 2 is close to the sensing section 22, information indicating that the actuator 20 of the third switch 2 is close to the sensing section 22, and information indicating that the actuators 20 of the other switches 2 are not close to the sensing section 22. In other words, the information indicating that the actuator 20 is close to the sensing section 22 is included in the High level portion of the open / close data portion of the pulse signal. The information indicating that the actuator 20 is not in proximity to the sensing unit 22 is the Low level portion of the open / close data portion of the pulse signal.

[0053] Here, a case will be described in which the actuator 20A of the switch 2A is adjacent to the sensing section 22A, the actuator 20C of the switch 2C is adjacent to the sensing section 22C, and the actuator 20B of the switch 2B is not adjacent to the sensing section 22B. When the actuator 20A is adjacent to the sensing section 22A, the control section 25A of the switch 2A sets the portion of the pulse signal corresponding to the switch 2A (the first portion of the open / close data section) to a High level (first value When the actuator 20C is close to the sensing unit 22C, the control unit 25C of the switch 2C sets the portion of the pulse signal corresponding to the switch 2C (the third portion of the open / close data portion) to When the actuator 20B is not close to the sensing unit 22B, the control unit 25B of the switch 2B sets the portion of the pulse signal corresponding to the switch 2B (the second portion of the open / close data portion) to a Low level (a second value). do.

[0054] When the actuator 20A is close to the sensing unit 22A, the control unit 25A of the switch 2A detects the part of the pulse signal corresponding to the switch 2A (the first part of the open / close data part). When the actuator 20C is close to the sensing unit 22C, the control unit 25C of the switch 2C may set the portion of the pulse signal corresponding to the switch 2C (the third portion of the open / close data portion) to a Low level (first value). When the actuator 20B is not close to the sensing unit 22B, the control unit 25B of the switch 2B outputs the second data of the open / close data portion of the pulse signal corresponding to the switch 2B. The other part (eye area) may be set to the High level (second value).

[0055] Next, with reference to FIG. 4, a communication protocol when the controller 1 acquires status information of the switch 2 will be described. The status information is information indicating the state of the switch 2, and is, for example, the accumulated power-on time obtained by accumulating the time when the switch 2 is powered. (C-1) of FIG. 4 is an example of a format of the communication protocol when the controller 1 acquires status information of the switch 2. (C-2) of FIG. 4 is an example of a waveform of a signal transmitted by the controller 1. (C-3) of FIG. 4 is an example of a waveform of a signal received by the controller 1. As shown in FIG. 4, a request ID section and a status buffer section are added next to the open / close data section. FIG. 4 shows an example of a request for status information to the 19th switch 2. For example, the controller 1 executes communication according to a communication protocol for acquiring status information instead of a normal communication protocol.

[0056] The request ID section is used by the controller 1 to specify the ID number of the switch 2 for which the controller 1 is requesting status information. Since 19 (decimal) = 0x13 (hexadecimal) = 00010011 (binary), the request ID section in (C-2) of FIG. 4 is composed of Low, Low, Low, High, Low, Low, High, High. The status buffer section of the pulse signal sent to each switch 2 is used to specify the contents of the status information. For example, if the number indicating the cumulative power-on time is 2 (decimal) = 0x02 (hexadecimal) = 00000010 (binary), the status buffer section in (C-2) of Figure 4 is as follows: It consists of Low, Low, Low, Low, Low, Low, High, Low.

[0057] When the controller 1 requests the accumulated energization time for the 19th switch 2, the The first switch 2 transmits a pulse signal shown in (C-2) in the above to the first switch 2. Each switch 2 checks the request ID section of the received pulse signal and judges whether or not the ID number specified by the request ID section matches its own ID number. If the ID number specified by the request ID section of the pulse signal does not match its own ID number, each switch 2 includes proximity information in the section of the open / close data section of the pulse signal that corresponds to its own ID number and After updating the parity part of the signal, the switch 2 in the next stage or the controller 1 transmits a pulse signal. In this case, each switch 2 changes the status buffer part of the pulse signal. Without any change, the switch 2 or the controller 1 transmits a pulse signal to the subsequent switch 2 or the controller 1.

[0058] On the other hand, if the ID number specified by the request ID part of the pulse signal matches its own ID number, switch 2 (the 19th switch 2 in the example shown in FIG. 4) updates the status buffer part of the pulse signal to the requested data (the cumulative power-on time in the example shown in FIG. 4). For example, the 19th switch 2 updates the status buffer of the pulse signal to the requested cumulative energization time, as shown in (C-3) of FIG. 4. If the cumulative energization time is 57 hours, In this case, 57 (decimal) = 0x39 (hexadecimal) = 00111001, so the status buffer part of the pulse signal in (C-3) of Figure 4 is Low, Low, High, H. The 19th switch 2 writes proximity information to the part of the open / close data section of the pulse signal that corresponds to its own ID number. The controller 1 analyzes the status buffer portion of the received pulse signal and obtains the requested data (the cumulative power-on time in the example shown in FIG. 4) .

[0059] The controller 1 includes request information for requesting status information indicating the state of the switch 2 in a pulse signal to be sent to the switch 2A, and transmits the pulse signal to the switch 2A. The control unit 25 of each switch 2 determines whether or not status information is requested based on the request ID portion included in the pulse signal, and if status information is requested, includes the status information in the pulse signal. The controller 1 is able to acquire status information of the switch 2 by analyzing the pulse signal received from the switch 2C and checking the status information included in the pulse signal.

[0060] In the example shown in FIG. 4, the controller 1 requests status information from the 19th switch 2, but the present invention is not limited to this example, and the controller 1 may request status information from multiple switches 2. When requesting status information from multiple switches 2, the controller 1 may request status information from multiple request ID sections and multiple status buffer sections. For example, the controller 1 generates a pulse signal including a request ID section and a status buffer section for requesting status information from the 17th switch 2, and A request ID section and a status buffer section for requesting status information from switch 2. , to generate a pulse signal including:

[0061] The controller 1 may execute, for example, the calculation of a function block having the function shown in Fig. 5. Fig. 5 is an explanatory diagram of the function of the function block. The function block (FB) includes an input unit 101 that receives an input of a pulse signal received via a signal line 3D, an input unit 102 that receives an input of a pulse signal received via a signal line 4D, an input unit 103 that receives an input of the number of switches 2 to be connected in series, and output units 104 and 105.

[0062] The outputs of the output units 104 and 105 will be described. Here, a case will be described in which the part of the pulse signal corresponding to each switch 2 is set to a High level value when the actuator 20 is close to the sensing unit 22. When the data section is composed entirely of high-level values, the output section 104 outputs a high The open / close data part of the pulse signal received by controller 1 is If a low-level value is included, a low-level value is output from the output unit 104. Byte data is output from the output unit 105. For example, if the maximum number of connections of the switch 2 is 30, each bit of the 4-byte (32-bit) data represents the proximity information of each switch 2. 105A (Output Enable (No. 1)), output unit 105B (Output Enable (No. 2)), etc. By outputting the proximity information of each switch 2 individually, the user does not need to perform bit calculations. This eliminates the need for a separate switch, improving usability.

[0063] <Additional Notes> A switch system comprising a controller (1), a plurality of switches (2), and signal lines (3, 4) connecting the controller (1) and the plurality of switches (2) in a ring shape, wherein a signal transmitted from the controller (1) to a first switch (2A) which is one of the plurality of switches (2) passes through the plurality of switches (2) in order and is returned to the controller (1) from a second switch (2C) which is one of the plurality of switches (2), Each of the plurality of switches (2) includes an actuator (20), a detection unit (22) that detects the proximity of the actuator (20), a receiving unit (23) that receives the signal via the signal lines (3, 4), a control unit (25) that includes, in the signal, proximity information indicating whether or not the actuator is in proximity to the detection unit, and a transmitting unit (24) that transmits, via the signal line, the signal including the proximity information; The signal received by the controller (1) from the second switch (2C) includes the proximity information of each of the plurality of switches (2). Switch system. [Explanation of symbols]

[0064] 1: Controller 2, 2A, 2B, 2C: Switch 3: Signal line 4: Signal line 20: Actuator 21: Sensor section 22: Sensing section 23: Receiving unit 24: Transmitter 25: Control unit

Claims

1. A switch system comprising: a controller; a plurality of switches; and a signal line connecting the controller and the plurality of switches in a ring shape, wherein a signal transmitted from the controller to a first switch which is one of the plurality of switches passes through the plurality of switches in order and is returned to the controller from a second switch which is one of the plurality of switches, Each of the plurality of switches includes an actuator, a detection unit that detects the proximity of the actuator, a receiving unit that receives the signal via the signal line, a control unit that causes the signal to include proximity information indicating whether the actuator is in proximity to the detection unit, and a transmitting unit that transmits the signal including the proximity information via the signal line, the signal received by the controller from the second switch includes the proximity information for each of the plurality of switches; The control units of the plurality of switches determine whether or not the signal includes a predetermined pattern, and select a first mode when the signal includes the predetermined pattern, and select a second mode when the signal does not include the predetermined pattern; In the first mode, the control unit causes the signal to include the proximity information, and the transmission unit transmits the signal including the proximity information via the signal line; In the second mode, when the signal is in a first state and the actuator is close to the detection unit, the control unit maintains the signal in the first state, and the transmission unit transmits the signal in the first state via the signal line; In the second mode, when the signal is in the first state and the actuator is not in proximity to the detection unit, the control unit changes the signal to a second state, and the transmission unit transmits the signal in the second state via the signal line; In the second mode, when the signal is in the second state, the control unit maintains the signal in the second state, and the transmission unit transmits the signal in the second state via the signal line. Switch system.

2. The proximity information of each of the plurality of switches is included in a portion of the signal corresponding to each of the plurality of switches.

2. The switch system of claim 1.

3. the signal has a first value and a second value; The control unit of the plurality of switches sets the portions of the signal corresponding to each of the plurality of switches to the first value when the actuator is close to the detection unit, and sets the portions of the signal corresponding to each of the plurality of switches to the second value when the actuator is not close to the detection unit.

3. The switch system of claim 2.

4. the first value is a high level, The second value is a low level.

4. The switch system of claim 3.

5. the first value is a low level, The second value is a high level.

4. The switch system of claim 3.

6. the controller includes request information for requesting status information indicating a state of the first switch in the signal to be transmitted to the first switch; the control units of the plurality of switches determine whether or not the status information is requested based on the request information included in the signal, and if the status information is requested, include the status information in the signal; The signal received by the controller from the second switch includes the status information of at least one of the plurality of switches. A switching system according to any one of claims 1 to 5.

7. the first state is an on state; The second state is an off state. A switching system according to any one of claims 1 to 6.

8. the first state is an off state; The second state is an on state. A switching system according to any one of claims 1 to 6.

9. The controller transmits the signal not including the predetermined pattern to the first switch before transmitting the signal including the predetermined pattern to the first switch. A switching system according to any one of claims 1 to 8.

10. the signal line includes a first signal line and a second signal line, the controller transmits the signal including the predetermined pattern to the first switch via the first signal line, and transmits the signal not including the predetermined pattern to the first switch via the second signal line; The transmitting units of the plurality of switches transmit the signal including the proximity information via the first signal line, and transmit the signal in the first state or the second state via the second signal line. A switching system according to any one of claims 1 to 9.

11. 11. One of the plurality of switches in the switch system according to claim 1, The signal line is connected to the controller. switch.

12. One of the switches in the switch system according to any one of claims 1 to 10, The signal line is connected to other two of the plurality of switches. switch.

13. A switch in a switch system, in which a signal transmitted from a controller to one of the plurality of switches via a signal line connecting the controller and the plurality of switches in a ring shape passes through the plurality of switches in order and is returned from the one of the plurality of switches to the controller, An actuator; A detection unit that detects the proximity of the actuator; a receiving unit that receives the signal via the signal line; A control unit that determines whether the signal includes a predetermined pattern; a transmitter for transmitting the signal via the signal line; Equipped with The control unit selects a first mode when the signal includes the predetermined pattern, and selects a second mode when the signal does not include the predetermined pattern; In the first mode, the control unit causes the signal to include proximity information indicating whether the actuating body is in proximity to the detection unit, and the transmission unit transmits the signal including the proximity information via the signal line; In the second mode, when the signal is in a first state and the actuator is close to the detection unit, the control unit maintains the signal in the first state, and the transmission unit transmits the signal in the first state via the signal line; In the second mode, when the signal is in the first state and the actuator is not in proximity to the detection unit, the control unit changes the signal to a second state, and the transmission unit transmits the signal in the second state via the signal line; In the second mode, when the signal is in the second state, the control unit maintains the signal in the second state, and the transmission unit transmits the signal in the second state via the signal line. switch.

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