COMMUNICATION SYSTEM, POWER SUPPLY, AND MASTER DEVICE

Abstract

To enable communication with a desired slave device even when the slave device or the master device cannot be easily physically accessed. [Solution] The communication system 100 includes a master device 7, a plurality of slave devices 20 that communicate in a manner that responds to inquiries from the master device 7, and a power supply unit 10 that supplements the power supply of the communication system 100, and the power supply unit 10 includes a third connection terminal 116 to which an external device that performs a predetermined task on the slave device 20 is connected, and a control unit 114 that mediates communication between a specific slave device 20 of the plurality of slave devices 20 and the external device when the external device is connected to the third connection terminal 116.

Description

[Technical Field]

[0001] The disclosed technology relates to a communication system, a power supply device, and a master device. [Background technology]

[0002] In a conventional system for supplying power and transmitting and receiving signals between a parent station and multiple child stations, the longer the connecting cable, the greater the transmission loss, which can lead to a problem of insufficient voltage supply (hereinafter referred to as "drop") to child stations connected far from the parent station.

[0003] For example, Patent Document 1 discloses a so-called master-slave communication system in which a cable extending from a parent station as a master device arranged in a control panel, including a power line and a signal line, is branched using multiple branching connectors to supply power voltage and signals to multiple child stations as slave devices. This communication system is configured so that a separate power supply is provided at a location where the power supply voltage drops below a predetermined value to compensate for the power shortage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-255871 Summary of the Invention [Problem to be solved by the invention]

[0005] When the above-described communication system is applied to factory automation, the slave devices are control devices such as servo amplifiers that control electric actuators. In this case, it is assumed that a main controller, acting as a master device, sends command signals to each control device to control the operation of each electric actuator.

[0006] In this type of application, there is a demand for connecting an external device such as a personal computer to the control device of the electric actuator in question in order to monitor the operating conditions, etc.

[0007] However, in the above application examples, multiple electric actuators may be combined to form a single working device, and in particular, if the slave device is a control device integrated with the electric actuator, physical access to the slave device may not be easy.

[0008] Although it is possible to connect an external device to the master device for monitoring, the master device is often installed inside a control panel, which may be located far away. In this case, every time an external device is connected, an operator must go to the control panel and physically access the master device, which can be difficult to access.

[0009] The present disclosure has been made in consideration of the above points, and aims to provide a communication system, a power supply unit, and a master device that enable communication with a desired slave device even when the slave device or master device is not easily physically accessible. [Means for solving the problem]

[0010] A communication system according to a first aspect of the present disclosure includes a master device having master authority in a master-slave communication system, a plurality of slave devices that communicate in a manner that responds to inquiries from the master device, and a power supply apparatus that supplements the power supply of the communication system, the power supply apparatus including: a connection terminal to which an external device that performs a predetermined task on the slave device is connected; and a communication unit that mediates communication between a specific slave device of the plurality of slave devices and the external device when the external device is connected to the connection terminal.

[0011] According to the communication system of the first aspect, communication with a desired slave device can be performed even when the slave device or the master device is not easily physically accessible.

[0012] A communication system according to a second aspect of the present disclosure is the communication system according to the first aspect, wherein the communication unit is capable of transmitting a request signal to the master device requesting that the master device stop querying each of the slave devices when the external device is connected to the connection terminal.

[0013] According to the communication system of the second aspect, the power supply device can request the master device to stop functioning in response to connection of an external device.

[0014] A communication system according to a third aspect of the present disclosure is the communication system according to the second aspect, wherein the master device stops inquiring of each of the slave devices upon receiving the request signal.

[0015] According to the communication system of the third aspect, it is possible to stop the function of the master device in response to a request from the power supply device.

[0016] A communication system according to a fourth aspect of the present disclosure is the communication system according to the second aspect, wherein, upon receiving the request signal, the master device delegates the master authority to the power supply apparatus that transmitted the request signal.

[0017] According to the communication system of the fourth aspect, the power supply device can be made the master device in response to a request from the power supply device.

[0018] A communication system according to a fifth aspect of the present disclosure is the communication system according to any one of the first to fourth aspects, further comprising: a main cable including signal lines and power lines; a plurality of branching means provided for each of the slave devices, the branching means branching the signal lines and the power lines on the main cable; and a plurality of branch cables provided for each of the slave devices, the branching means connecting the signal lines and the power lines branched by the branching means, wherein the master device is connected to a main power source arranged in a control panel, and communicates with and supplies power to the plurality of slave devices via the main cable, the plurality of branching means, and the plurality of branch cables, and the power supply apparatus is connected to the master device and the slave devices via the main cable.

[0019] According to the communication system of the fifth aspect, the power supply device, the master device, and the slave device can be connected via a main cable including a signal line and a power line.

[0020] A communication system according to a sixth aspect of the present disclosure is the communication system according to the fifth aspect, wherein the slave device is a control device that controls an electric actuator as a control target in response to a command signal from the master device.

[0021] According to the communication system of the sixth aspect, it is possible to control an electric actuator as a control target of a slave device.

[0022] A communication system according to a seventh aspect of the present disclosure is the communication system according to the sixth aspect, wherein the slave device is an electric actuator integrated control device in which the electric actuator and the control device are integrated.

[0023] According to the communication system of the seventh aspect, it is possible to control an electric actuator integrated with a control device as a control target of a slave device.

[0024] A power supply device according to an eighth aspect of the present disclosure is a power supply device that supplements the power supply of a master-slave communication system including a master device having master authority in the communication system and a plurality of slave devices that communicate in a manner that responds to inquiries from the master device, and includes a connection terminal to which an external device that performs a predetermined task on the slave device is connected, and a communication unit that mediates communication between a specific slave device among the plurality of slave devices and the external device when the external device is connected to the connection terminal.

[0025] According to the power supply device of the eighth aspect, communication with a desired slave device can be performed even if the slave device or master device is not easily physically accessible.

[0026] A power supply device according to a ninth aspect of the present disclosure is the power supply device according to the eighth aspect, wherein the communication unit is capable of transmitting a request signal to the master device requesting that the master device stop querying each of the slave devices when the external device is connected to the connection terminal.

[0027] According to the power supply device of the ninth aspect, it is possible to request the suspension of the master device functions from the power supply device in response to the connection of an external device.

[0028] A power supply device according to a tenth aspect of the present disclosure is the power supply device according to the ninth aspect, wherein the communication unit has the master authority delegated from the master device after transmitting the request signal.

[0029] According to the power supply device of the tenth aspect, the power supply device can be made the master device in response to a request from the power supply device.

[0030] A master device according to an eleventh aspect of the present disclosure is a master device in a master-slave communication system that communicates by querying a plurality of slave devices and receiving responses from the slave devices, has master authority in the communication system, and receives a request signal that is transmitted from a power supply device that supplements the power supply of the communication system and requests the slave devices to stop querying the slave devices.

[0031] The master device according to the eleventh aspect can receive a request from the power supply device to stop the functions of the master device.

[0032] A master device according to a twelfth aspect of the present disclosure is the master device according to the eleventh aspect, wherein upon receiving the request signal, the master device stops making inquiries to the slave device.

[0033] According to the master device of the twelfth aspect, the function of the master device can be stopped in response to a request from the power supply device.

[0034] A master device according to a thirteenth aspect of the present disclosure is the master device according to the eleventh aspect, wherein upon receiving the request signal, the master device transfers the master authority to the power supply apparatus that transmitted the request signal.

[0035] According to the master device of the thirteenth aspect, the power supply device can become the master device in response to a request from the power supply device. [Effects of the Invention]

[0036] According to the disclosed technology, communication with a desired slave device can be made possible even when the slave device or master device is not easily physically accessible. [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a block diagram showing an example of the overall configuration of a communication system according to an embodiment. [Figure 2]1 is a block diagram illustrating an example of a configuration of a main part of a communication system according to an embodiment. [Figure 3] FIG. 2 is a diagram illustrating an example of a hardware configuration including a control unit in a power supply device according to an embodiment. [Figure 4] FIG. 10 is a sequence diagram illustrating an example of a communication process between a master device and a power supply device according to the embodiment. [Figure 5] FIG. 10 is a sequence diagram illustrating another example of communication processing between a master device and a power supply device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0038] An example of an embodiment of the disclosed technology will be described below with reference to the drawings. Note that the same or equivalent components and parts in each drawing are given the same reference numerals. Also, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0039] 1 is a block diagram showing an example of the overall configuration of a communication system 100 according to this embodiment. The communication system 100 according to this embodiment includes a PLC (Programmable Logic Controller) 4, a main power supply 5, a master device 7, a branching unit 15, a slave device 20, a power supply unit 10, a main cable 9, a branch cable 17, and a power cable 3. Note that, for example, a plurality of branching units 15, slave devices 20, power supply units 10, main cables 9, branch cables 17, and power cables 3 may be provided. Here, when identifying each of the power supply unit 10, main cables 9, and power cables 3, the letters A and B may be added to the reference numerals.

[0040] As shown in FIG. 1 , in the communication system 100, a commercial AC power supply 2 is used as a starting point, and a main power supply 5, a master device 7, a power supply unit 10A, and a power supply unit 10B are arranged in this order. Note that, although two power supply units 10A and 10B are shown as power supply units 10 in the communication system 100, the present invention is not limited to this. One power supply unit or three or more power supplies may be arranged depending on the desired power capacity. The master device 7 and the power supply unit 10 are electrically connected by a main cable 9. In the communication system 100, the power supply units 10 are provided on a single line formed by the main cable 9. That is, the power supply unit 10 is connected to the master device 7 and the slave device 20 via the main cable 9. The commercial AC power supply 2, the main power supply 5, and the master device 7 are installed, for example, in a control panel 1 in a factory.

[0041] A plurality of branching means 15 are connected to each main cable 9. A plurality of slave devices 20 are electrically connected to the corresponding branching means 15 via branch cables 17. In other words, the branch cables 17 are provided so as to branch off from the main cable 9 via the branching means 15.

[0042] The master device 7 is connected to a main power supply 5 arranged in the control panel 1 and communicates with the multiple slave devices 20 via a main cable 9, multiple branching means 15, and multiple branch cables 17. The master device 7 also supplies power to the multiple slave devices 20 and to the electric actuators 22 (described later). The master device 7 functions as the main controller of the communication system 100 and is connectable to a PLC 4, which is a higher-level device. More specifically, the master device 7 functions as a gateway that distributes information from the PLC 4 to each slave device 20. However, this is not a limitation. The communication system 100 may omit the PLC 4 and the master device 7 may directly inquire and command the slave devices 20. Furthermore, the slave devices 20 communicate by responding to inquiries from the master device 7, and each slave device 20 has the function of controlling a predetermined control target. The master device 7 and the multiple slave devices 20 communicate using a master-slave communication protocol such as Modbus. The master device 7 has master authority to proactively issue commands and queries to the multiple slave devices 20. The slave device 20 is connected to the master device 7 by a so-called multi-drop method. Specifically, the slave device 20 has a unique address (hereinafter referred to as a "slave address"). The master device 7 transmits an inquiry signal including a command to the slave device 20 having a predetermined slave address, and the slave device 20 assigned the predetermined slave address controls the controlled object according to the command from the master device 7 and responds to the master device 7.

[0043] FIG. 2 is a block diagram showing an example of a main configuration of a communication system 100 according to this embodiment. The slave device 20 is, for example, a subcontroller 21 that controls an electric actuator 22. The electric actuator 22 is an example of a predetermined control target, such as an industrial actuator that uses a motor as a drive source to move a moving object. The subcontroller 21 is a control device that controls the electric actuator 22 and has the function of controlling the movement of each electric actuator 22. The subcontroller 21 includes a smoothing capacitor, a driver, a control unit, and a control voltage generation circuit. The control unit of the subcontroller 21 controls the driver based on a command signal from the master device 7, which is a higher-level device, thereby controlling the power supplied to the motor and controlling the electric actuator 22. The control voltage generation circuit of the subcontroller 21 is, for example, a downconverter, and generates a voltage suitable for operation of the control unit from a control power supply voltage of DC power supplied from the master device 7 or the power supply device 10. The master device 7, which is provided adjacent to the main power supply 5, controls a specific slave device 20 among the multiple slave devices 20 to operate. That is, the master device 7 outputs a signal including a command signal that commands the operation of the electric actuator 22 controlled by the slave device 20.

[0044] In this example, the slave device 20 is an electric actuator-integrated sub-controller 21 integrated with the electric actuator 22. However, the present invention is not limited to this, and the slave device 20 may be a sub-controller 21 separate from the electric actuator 22. Examples of the predetermined control target include a motor roller (a motorized roller for a conveyor) or a roller conveyor used in a transport system, and the slave device 20 may be configured together with a control device that controls the motor roller or roller conveyor. Alternatively, the slave device 20 may be a control device that controls a load that consumes power from a power supply, such as a servo amplifier that controls a servo motor or a control device that controls lighting. The slave device 20 may also be an input / output device (I / O unit). The input / output device can be connected to either the main cable 9 or the branch cable 17.

[0045] 1, main power supply 5 receives AC power from commercial AC power supply 2 and outputs DC power to each power supply device 10 via master device 7. Note that main power supply 5 may have the same configuration as power supply device 10, or may be a general-purpose power supply device with a different configuration from power supply device 10.

[0046] The power supply device 10 supplements the power supply for the communication system 100 and has, for example, a dustproof and drip-proof sealed structure. Specifically, it meets the protection rating of IP20 or higher of the International Electrotechnical Commission (IEC) 60529. For example, if the protection rating is IP54 or higher, and the power supply device 10 meets the protection rating of IP21 or higher, it will have a high level of dustproof and drip-proof configuration. This makes it possible to install the power supply device 10 not only outside the control panel 1, but also in places where even stricter standards are set. In other words, the degree of freedom in the placement of the power supply device 10 can be increased.

[0047] One or more power supply devices 10 can be provided on a line formed by a main cable 9. A power cable 3 is connected to each power supply device 10. The power supply devices 10 are, for example, switching power supplies that can operate in parallel with multiple devices. The main power supply 5 and the multiple power supply devices 10 are connected in parallel in terms of how the power cables 3 are connected. The power cables 3 include a power cable 3A that connects the commercial AC power supply 2 and the power supply devices 10, and a power cable 3B that connects the power supply devices 10 to each other. Each power supply device 10 does not have to be connected to the commercial AC power supply 2. Each power supply device 10 may receive AC power via the main power supply 5.

[0048] As an example, the main cable 9 is a cable in which a power line 18 and a signal line 19 are integrally formed, as shown in FIG. 2 . The main cable 9 is, for example, a flat cable in which two power lines and three signal lines are aligned in a row in cross section. However, the main cable 9 is not limited to having two power lines and three signal lines. For example, the main cable 9 may have three or more power lines 18 and at least one or four or more signal lines 19. Furthermore, the main cable 9 is not limited to a flat cable. It may also be a round cable in which two power lines and three signal lines are gathered in a circular shape in cross section. The power line 18 supplies DC power to each slave device 20 (more specifically, the sub-controller 21 and the electric actuator 22). The signal line 19 supplies a control signal for controlling the electric actuator 22 to each slave device 20. The main cable 9 includes a main cable 9A connecting the master device 7 and the power supply unit 10 and a main cable 9B connecting the power supply units 10 to each other.

[0049] The branching means 15 is provided for each slave device 20 and is a branching connector that branches the power line 18 and the signal line 19 of the main cable 9. However, the branching means 15 is not limited to a branching connector as long as it can branch the power line 18 and the signal line 19 of the main cable 9 and connect to a branch cable 17, which will be described later. Note that at least one branching means 15 is connected to the main cable 9, but this is not limited to this depending on the system configuration. A plurality of branching means 15 according to this embodiment are arranged between the master device 7 and the power supply device 10 (i.e., for the main cable 9A) and between the power supply devices 10 (i.e., for the main cable 9B).

[0050] The branch cable 17 is provided for each slave device 20 and is connected to a power line 18 and a signal line 19 branched by the branching means 15. In other words, the branch cable 17 supplies DC power and command signals to the slave devices 20.

[0051] Next, the functions and configuration of the power supply device 10 will be described in detail using the power supply device 10A as an example. The power supply device 10B also has the same functions and configuration as the power supply device 10A. As shown in FIG. 2, the power supply device 10A has a generator 110 that generates DC power from AC power. The generator 110 is composed of an AC / DC converter that includes a transformer for driving the actuator, a transformer for operating the subcontroller, switching elements for controlling both transformers, a rectifier, and a capacitor. The rectifier converts the negative voltage component of the input voltage into a positive voltage and rectifies it to DC, or eliminates the negative input voltage component to generate DC. The capacitor is used to smooth the pulse wave.

[0052] The power supply device 10A also has a first connection terminal 13 to which the main cable 9A is connected and a second connection terminal 14 to which the main cable 9B is connected. Here, the first connection terminal 13 and the second connection terminal 14 each include a power terminal connected to the power line 18 of the main cable 9 and a signal terminal connected to the signal line 19 of the main cable 9.

[0053] The power supply terminal of the first connection terminal 13, the power supply terminal of the second connection terminal 14, and the generation unit 110 are connected by a power line inside the power supply device 10. That is, the power supply terminal of the first connection terminal 13, the power supply terminal of the second connection terminal 14, and the generation unit 110 of each power supply device 10 are all connected via main cables 9A and 9B, so that the transmission paths of DC power are all electrically connected.

[0054] Furthermore, the signal terminal of the first connection terminal 13 and the signal terminal of the second connection terminal 14 are directly connected by a signal line inside the power supply device 10. Supplementally, the signal line connecting the first connection terminal 13 and the second connection terminal 14 bypasses the inside of the power supply device 10 and is also connected to the CPU of the control unit 114 (see FIG. 3 described later). That is, the power supply device 10 is connected to the master device 7 by a so-called multi-drop method. However, this is not a limitation. The first connection terminal 13 may be a signal input terminal, the second connection terminal 14 may be a signal output terminal, and the first connection terminal 13 and the second connection terminal 14 may each be connected to the CPU (see FIG. 3 described later) by separate signal lines. In this case, for example, the power supply device 10A realizes communication by transferring a signal from the master device 7 to the power supply device 10B. That is, the power supply device 10 may be connected to the master device 7 by a so-called daisy chain method.

[0055] Furthermore, power supply device 10 has an input terminal 11 connected to power cable 3A and an output terminal 12 connected to power cable 3B. Power cable 3A, power cable 3B, and generation unit 110 are connected by a power cable inside power supply device 10. As a result, AC power input from power cable 3A is supplied to generation unit 110 and is also output to power cable 3B.

[0056] In addition to the generating unit 110, the power supply device 10 includes a detecting unit 112 and a controlling unit 114. In the power supply device 10, the generating unit 110, the detecting unit 112, and the controlling unit 114 function to perform feedback control on the DC power. The reason for performing feedback control is that the power supply device 10 is capable of parallel operation, and the output voltage may fluctuate within ±10% of the rated value depending on the load even during normal operation.

[0057] As described above, the generating unit 110 has a function of generating DC power from AC power.

[0058] The detection unit 112 has a function of detecting the current of the DC power generated by the generation unit 110. Specifically, the detection unit 112 detects the output current from the generation unit 110 using, for example, a shunt resistor, and outputs the voltage value of the output current to the control unit 114.

[0059] The control unit 114 has a function of controlling the voltage of the DC power generated by the generation unit 110 (hereinafter referred to as a "voltage adjustment function"). Specifically, the control unit 114 controls the voltage of the DC power to be output according to the voltage value detected by the detection unit 112. For example, the control unit 114 adjusts the voltage of the DC power to be output by controlling a switching element. Specifically, when the actual output voltage value is lower than the target voltage value, the control unit 114 controls the switching element so that the ON period of the switching element is extended. On the other hand, when the actual output voltage value is higher than the target voltage value, the control unit 114 controls the switching element so that the ON period of the switching element is shortened. In this way, the control unit 114 constantly checks the actual output voltage value and controls the ON / OFF time of the switching element based on that value, thereby stably ensuring the target output voltage value. Note that this voltage adjustment function may be realized by using a control IC (Integrated Circuit) provided separately from the control unit 114.

[0060] As described above, the output current of the power supply device 10 varies depending on the load of each slave device 20. Therefore, as the output current increases, the control unit 114 reduces the output voltage, thereby balancing the output of each power supply device 10 and achieving parallel operation. This also has the advantage of distributing the load on each power supply device 10. More specifically, the communication system 100 is configured such that a plurality of power supply devices 10 capable of parallel operation are connected in parallel via the main cable 9, and supply power to the slave devices 20 via the branch cable 17. That is, the first connection terminal 13, the second connection terminal 14, and the generation unit 110 of all the power supply devices 10 are electrically connected via the main cable 9. This makes it possible to effectively achieve parallel operation in which the output of each power supply device 10 is balanced, thereby substantially equalizing the load on each power supply device 10.

[0061] The power supply device 10 is provided with a connection terminal 116 (hereinafter referred to as the "third connection terminal 116") to which an external device is connected. Communication with the external device may be wired or wireless. Various communication methods, such as Universal Serial Bus (USB), wireless local area network (wireless LAN), and near field communication (NFC), are applicable to the third connection terminal 116. The external device is a device that performs a predetermined task on a control target of the slave device 20. Examples of the external device include a personal computer (PC), a tablet terminal, a smartphone, etc., on which software required to perform the predetermined task is installed. The predetermined task includes tasks such as monitoring the control target and setting the operation of the control target. Specifically, the predetermined task includes, for example, monitoring the operating status of the electric actuator 22, reading and writing parameters of the slave device 20, changing data such as the target position, speed, and acceleration of the movable part of the electric actuator 22, and setting the operation of the electric actuator 22. Furthermore, when the slave device 20 is an input / output device, the predetermined tasks include setting (reading and writing) parameters of the input / output device, test running and monitoring of equipment connected to the input / output device, as well as, for example, forced OUT (output) and input confirmation.

[0062] Next, with reference to FIG. 3, a specific description will be given of a form in which the external device 30 and the slave device 20 communicate with each other via the power supply device 10. FIG.

[0063] Fig. 3 is a diagram schematically illustrating an example of a hardware configuration including a control unit 114 in the power supply device 10 according to this embodiment. Note that, in Fig. 3, for the sake of simplicity, the input terminal 11, the output terminal 12, the first connection terminal 13, and the second connection terminal 14 are omitted from illustration.

[0064] 3, the control unit 114 includes a CPU (Central Processing Unit) 51, a ROM (Read Only Memory) 52, a RAM (Random Access Memory) 53, a first communication I / O (Input / Output) 54, and a second communication I / O 55. Each component is connected to each other via a bus 56 so as to be able to communicate with each other.

[0065] The CPU 51 is a central processing unit that executes various programs and controls various components. The ROM 52 stores various programs and data. The RAM 53 temporarily stores programs or data as a work area. That is, the CPU 51 reads a program from the ROM 52 and executes the program using the RAM 53 as a work area.

[0066] The first communication I / O 54 is an input / output interface for communication between the master device 7 and the slave device 20. The first communication I / O 54 is connected to the master device 7 and the slave device 20, and is also connected to the generation unit 110 and the detection unit 112. On the other hand, the second communication I / O 55 is connected to the third connection terminal 116, and is an input / output interface for communication with the external device 30 connected to the third connection terminal 116.

[0067] The CPU 51 is an example of a communication unit, and has a function (hereinafter referred to as a "communication intermediation function") of mediating communication between a specific slave device 20 among the plurality of slave devices 20 and the external device 30 when the external device 30 is connected to the third connection terminal 116. Note that if there are a plurality of power supply devices 10, the communication intermediation function of the power supply device 10 to which the external device 30 is connected earliest in chronological order is enabled.

[0068] Here, the multiple slave devices 20 and the power supply 10 have unique slave addresses, allowing each to be identified individually. Because each command and query message from the master device 7 includes a slave address, the power supply 10 can identify whether the command signal is addressed to itself. Normally, that is, when the external device 30 is not connected to the third connection terminal 116, the CPU 51 does not issue any commands to the power supply 10. Furthermore, the master device 7 issues queries to the power supply 10 as well as to each slave device 20, but the query messages addressed to each slave device 20 do not include the slave address of the power supply 10. The CPU 51 determines that a command or query from the master device 7 addressed to each slave device 20 is not addressed to itself and ignores the command. In this case, the CPU 51 does not respond to the command signal from the master device 7. On the other hand, in response to a query addressed to itself from the master device 7, the CPU 51 replies to the master device 7 by indicating that there is no request from the master device 7 or by requesting that the query be stopped, as described below.

[0069] On the other hand, when the external device 30 is connected to the third connection terminal 116, the CPU 51 is capable of transmitting to the master device 7 a request signal requesting the master device 7 to stop querying each slave device 20. Here, "when the external device 30 is connected to the third connection terminal 116" may be, for example, the timing when the external device 30 is connected to the third connection terminal 116, or the timing when the external device 30 is connected to the third connection terminal 116 and the user performs an explicit operation to instruct the start of connection. In other words, it may be the timing when the external device 30 is automatically recognized, or the timing when the external device 30 is recognized in accordance with a user operation.

[0070] When the master device 7 receives a request signal from the power supply device 10, it may stop making inquiries to each slave device 20. Furthermore, when the master device 7 receives a request signal from the power supply device 10, it may delegate the authority as the master device (master authority) to the power supply device 10 that sent the request signal. When the master authority is delegated to the power supply device 10, the slave address previously assigned to the power supply device 10 will no longer be used. Furthermore, the master device 7 that previously had master authority may be assigned a new slave address, or may not be assigned any slave address at all.

[0071] When the external device 30 is connected to the third connection terminal 116, the function of the CPU 51 differs depending on whether the power supply device 10 has master authority. When the power supply device 10 does not have master authority, upon receiving a signal addressed to a specific slave device 20 from the external device 30, the CPU 51 determines that the signal is not a command addressed to itself and passes the signal through (refuses reception). Upon receiving a signal addressed to the external device 30 from the specific slave device 20, the CPU 51 similarly determines that the signal is not a command addressed to itself and passes the signal through, thereby allowing communication between the specific slave device 20 and the external device 30. On the other hand, when the power supply device 10 has master authority, in addition to the function it has when it does not have master authority (hereinafter referred to as the "first function"), the CPU 51 has the following function. First, the CPU 51 has a second function of issuing commands or inquiries to the specific slave device 20 in response to commands from the external device 30. Furthermore, the CPU 51 has a third function that it performed when the master device 7 had master authority. More specifically, the third function includes a function to acquire information from the PLC 4 via the master device 7, which does not have master authority (in this case, the master device 7 passes signals from the PLC 4 to the power supply device 10), and distribute the information to the slave device 20. Having the master authority, i.e., having the second and third functions in addition to the first function, provides the following advantages. Specifically, with only the first function, if the operation is switched from monitoring the operating status of the electric actuator 22 based on a command from the PLC 4 to adjusting the operation, including reading and writing parameters of the slave device 20, changing data such as the target position of the electric actuator 22, and setting operation settings, switching back to the monitoring operation is undesirable because the slave device 20 may suddenly start operating when switching back to the monitoring operation, depending on the timing of the command from the PLC 4. For this reason, such switching functions may be restricted. On the other hand, if the power supply device 10 has master authority, it can acquire information from the PLC 4 and distribute it to the slave device 20, allowing for flexible switching between monitoring and adjusting operations. This facilitates debugging of the entire communication system.

[0072] Next, the operation of the communication system 100 according to this embodiment will be described with reference to FIGS.

[0073] 4 is a sequence diagram showing an example of communication processing between the master device 7 and the power supply device 10 according to this embodiment. Each process in the power supply device 10 is executed by the CPU 51 functioning as the control unit 114. Note that the example in FIG. 4 shows a case where inquiries from the master device 7 are stopped when an external device 30 is connected.

[0074] In step S101 of FIG. 4, the master device 7 transmits an inquiry to the power supply device 10 periodically or at an arbitrary timing.

[0075] In step S102, the power supply device 10 returns a response to the inquiry from the master device 7 to the master device 7. Here, the power supply device 10 returns a response indicating that there is no request from the master device 7 because no external device 30 is connected. Note that the power supply device 10 may ignore the inquiry from the master device 7 without responding.

[0076] In step S103, the master device 7 transmits an inquiry to the power supply 10 periodically or at an arbitrary timing.

[0077] In step S104, the power supply 10 detects that the external device 30 has been connected to the third connection terminal 116.

[0078] In step S105, the power supply device 10 returns a response to the inquiry from the master device 7 to the master device 7. This response includes a request to the master device 7 to stop making inquiries because the external device 30 is connected.

[0079] In step S106, when the master device 7 receives a request to stop the inquiry from the power supply 10, it stops the inquiry to each slave device 20. Note that, for example, when the external device 30 is removed, when a predetermined operation is performed by the user, or when the system power is turned off, the stop of the inquiry to each slave device 20 can be released and the master device 7 can return to the normal state.

[0080] 5 is a sequence diagram showing another example of communication processing between the master device 7 and the power supply device 10 according to this embodiment. Each process in the power supply device 10 is executed by the CPU 51 functioning as the control unit 114. Note that the example in FIG. 5 shows a case where the master device 7 transfers the master authority when an external device 30 is connected.

[0081] In step S111 of FIG. 5, the master device 7 transmits an inquiry to the power supply 10 periodically or at an arbitrary timing.

[0082] In step S112, the power supply device 10 returns a response to the inquiry from the master device 7 to the master device 7. Here, the power supply device 10 returns a response indicating that there is no request from the master device 7 because no external device 30 is connected. Note that the power supply device 10 may ignore the inquiry from the master device 7 without responding.

[0083] In step S113, the master device 7 transmits an inquiry to the power supply 10 periodically or at an arbitrary timing.

[0084] In step S114, the power supply 10 detects that the external device 30 has been connected to the third connection terminal 116.

[0085] In step S115, the power supply device 10 returns a response to the inquiry from the master device 7 to the master device 7. This response includes a request to the master device 7 to stop making inquiries because the external device 30 is connected.

[0086] In step S116, when the master device 7 receives the inquiry stop request from the power supply device 10, it transmits a master authority transfer command to the power supply device 10.

[0087] In step S117, the power supply device 10 returns a response to the master authority transfer command from the master device 7 to the master device 7. That is, after transmitting the inquiry stop request, the master authority is transferred from the master device 7 to the power supply device 10.

[0088] In step S118, the power supply device 10 receives the transfer of master authority from the master device 7 and operates as the master device in place of the master device 7. Note that, for example, when the external device 30 is removed, when a predetermined operation is performed by the user, or when the system power is turned off, the transfer of master authority can be cancelled and the master device 7 can be returned to the normal state.

[0089] As described above, according to this embodiment, an external device can be connected to the power supply unit, and communication between the external device and the slave device can be performed via the power supply unit. Therefore, even if the slave device or master device cannot be easily physically accessed, communication with the desired slave device can be performed. [Explanation of symbols]

[0090] 1 Control panel 2 Commercial AC power supply 3 Power Cable 5 Main power 4 PLC 7 Master Device 9 Main Cable 10 Power supply 11 Input terminal 12 Output terminal 13 First connection terminal 14 Second connection terminal 15 Branching means 17 Branch Cable 18 Power line 19 Signal line 20 slave devices 30 External Devices 100 Communication Systems 110 Generation part 112 Detection unit 114 Control Unit 116 Third connection terminal

Claims

1. a master device having master authority in a master-slave communication system; a plurality of slave devices that communicate in a manner that responds to inquiries from the master device; a power supply device that supplements the power supply of the communication system, the power supply device including: a connection terminal to which an external device that performs a predetermined task on the slave device is connected; and a communication unit that mediates communication between a specific slave device among the plurality of slave devices and the external device when the external device is connected to the connection terminal; A communication system including:

2. the communication unit is capable of transmitting, when the external device is connected to the connection terminal, a request signal to the master device requesting that the master device stop making inquiries to each of the slave devices; The communication system of claim 1 .

3. When the master device receives the request signal, it stops inquiring about each of the slave devices. The communication system according to claim 2 .

4. Upon receiving the request signal, the master device transfers the master right to the power supply device that transmitted the request signal. The communication system according to claim 2 .

5. a main cable including a signal line and a power line; a plurality of branching means provided for each of the slave devices, for branching the signal line and the power line on the main cable; a plurality of branch cables provided for each of the slave devices and connected to the signal lines and the power lines branched by the branching means; Further provided with the master device is connected to a main power supply arranged in a control panel, and communicates with the plurality of slave devices via the main cable, the plurality of branching means, and the plurality of branch cables, and supplies power to the plurality of slave devices; the power supply device is connected to the master device and the slave device via the main line cable; The communication system according to any one of claims 1 to 4.

6. The slave device is a control device that controls an electric actuator as a control target in response to a command signal from the master device. The communication system according to claim 5 .

7. the slave device is an electric actuator integrated control device in which the electric actuator and the control device are integrated together, 7. The communication system according to claim 6.

8. A power supply device for supplementing power supply in a master-slave communication system, the power supply device including a master device having master authority in the communication system, and a plurality of slave devices that communicate in a manner that responds to inquiries from the master device, a connection terminal to which an external device that executes a predetermined task for the slave device is connected; a communication unit that mediates communication between a specific slave device among the plurality of slave devices and the external device when the external device is connected to the connection terminal; Including, power supply.

9. the communication unit is capable of transmitting, when the external device is connected to the connection terminal, a request signal to the master device requesting that the master device stop making inquiries to each of the slave devices; 9. The power supply device of claim 8.

10. the communication unit has the master authority delegated from the master device after transmitting the request signal; 10. The power supply device of claim 9.

11. A master device in a master-slave communication system that communicates by making inquiries to a plurality of slave devices and receiving responses from the slave devices, receiving a request signal transmitted from a power supply device having master authority in the communication system and supplementing the power supply of the communication system, the request signal requesting that inquiries to the slave device be stopped; Master device.

12. When the request signal is received, the inquiry to the slave device is stopped. The master device of claim 11 .

13. Upon receiving the request signal, the master authority is delegated to the power supply device that transmitted the request signal. The master device of claim 11 .

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