Terminal device and communication system

Abstract

The present invention sets a communication address to a next terminal device connected to a predetermined terminal device even if a failure occurs in the predetermined terminal device from among a plurality of terminal devices. A terminal device (10) has a communication address set therefor. The terminal device 10 comprises: communication terminals (Pa, Pb) to which communication signals for communicating with a management device are input / output; a communication circuit unit (60) connected to the communication terminals (Pa, Pb); an input terminal (E1) and an output terminal (E2); a control unit (50); and a diode (81) disposed on a path connecting the input terminal (E1) and the output terminal (E2). The control unit (50) is connected to each of the communication circuit unit (60), the input terminal (E1), and the output terminal (E2), controls the operation of the communication circuit unit (60) on the basis of a signal input to the input terminal (E1), and then outputs a predetermined signal via the output terminal (E2).

Description

Terminal device and communication system

[0001] The present disclosure relates to a terminal device in which a communication address is set, and a communication system including the terminal device.

[0002] Conventionally, a communication system has been known that includes a plurality of terminal devices and a management device that controls the plurality of terminal devices. In such a communication system, a communication address is assigned to each of the plurality of terminal devices, so that each terminal device can be individually controlled using the management device. Patent Document 1 discloses a communication system in which the management device and the plurality of terminal devices are daisy-chained.

[0003] US Patent Application Publication No. 2010 / 0274945

[0004] In a conventional communication system, if a communication address is not set for a specific terminal device among a plurality of terminal devices, the management device is configured to be unable to communicate with the next terminal device connected to the specific terminal device, and after a communication address is set for the specific terminal device, the management device is configured to be able to communicate with the next terminal device. However, in a conventional communication system, for example, if a malfunction occurs in the control circuit of a specific terminal device, a communication address cannot be set for the next terminal device.

[0005] The present disclosure provides a terminal device and a communication system including the same that are configured so that even if a malfunction occurs in a specific terminal device among multiple terminal devices, a communication address can be set to another terminal device other than the specific terminal device.

[0006] A terminal device according to one aspect of the present disclosure is a terminal device in which a communication address is set, and includes a communication terminal through which a communication signal for communicating with a management device is input and output, a communication circuit unit connected to the communication terminal, an input terminal and an output terminal, a control unit, and a diode or a transistor arranged on a path connecting the input terminal and the output terminal. The control unit is connected to the communication circuit unit, the input terminal, and the output terminal, and controls the operation of the communication circuit unit based on a signal input to the input terminal, and then outputs a predetermined signal via the output terminal.

[0007] A communication system according to another aspect of the present disclosure is a communication system including a plurality of terminal devices, each of which is the terminal device of the above aspect, and the management device, wherein the plurality of terminal devices include at least a first terminal device, a second terminal device, and a third terminal device, each of which is the terminal device, and the first terminal device, the second terminal device, and the third terminal device are bus-connected to the management device via the communication terminals of the first terminal device, the second terminal device, and the third terminal device. The input terminal of the first terminal device is connected to the management device. The output terminal of the first terminal device is connected to the input terminal of the second terminal device. The output terminal of the second terminal device is connected to the input terminal of the third terminal device.

[0008] According to the terminal device and communication system of the present disclosure, even if a malfunction occurs in a predetermined terminal device among a plurality of terminal devices, it is possible to set a communication address in another terminal device other than the predetermined terminal device.

[0009] 1 is a diagram showing a schematic configuration of a communication system according to an embodiment; FIG. 2 is a diagram showing a circuit configuration of a terminal device according to an embodiment; FIG. 3 is a diagram showing a connection relationship of a plurality of terminal devices included in a communication system; FIG. 4 is a diagram showing the relationship between the potential of an input terminal, the output of a logic circuit, the presence or absence of a drive voltage output from a linear regulator, and whether communication is possible or not of a transceiver IC; FIG. 5 is a diagram showing the relationship between the setting state of a communication address, the state of a voltage signal switching circuit, the potential of an output terminal, and the potential of an input terminal of a next terminal device; FIG. 6 is a diagram showing an example of setting a communication address of a terminal device according to an embodiment; FIG. 7 is a diagram showing the circuit configuration of a terminal device according to a first modification of an embodiment; FIG. 8 is a diagram showing the circuit configuration of a terminal device according to a second modification of an embodiment; and FIG. 9 is a diagram showing the circuit configuration of a terminal device according to a third modification of an embodiment.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim showing an implementation form of one aspect of the present disclosure will be described as optional components. Implementation forms of the present disclosure are not limited to the current independent claim, but may also be expressed by other independent claims.

[0011] It should be noted that the drawings are schematic diagrams and are not necessarily strict illustrations. In all drawings, the same reference numerals are used to denote substantially the same components, and redundant explanations may be omitted or simplified.

[0012] (Embodiment) [General Configuration of Communication System] A general configuration of a communication system according to an embodiment will be described with reference to FIG.

[0013] FIG. 1 is a diagram showing a schematic configuration of a communication system 1 according to an embodiment.

[0014] 1, the communication system 1 includes a management device 5 and a plurality of terminal devices 11, 12, 13, 14, and 15. Note that power lines for supplying power to the management device 5 and each of the terminal devices 11 to 15 are not shown in FIG.

[0015] The management device 5 is a device, such as a master controller, that controls the multiple terminal devices 11 to 15. The multiple terminal devices 11 to 15 are devices that operate based on control signals output from the management device 5, such as driving devices such as motors, or electrical devices such as air conditioning devices, lighting devices, imaging devices, display devices, and communication devices.

[0016] The management device 5 and the multiple terminal devices 11 to 15 are daisy-chain connected by multiple feeder lines L1 to L5. Each of the feeder lines L1 to L5 is, for example, a cable with a connector and multiple communication lines. In this example, the management device 5 and terminal device 11 are connected by feeder line L1, terminal device 11 and terminal device 12 are connected by feeder line L2, terminal device 12 and terminal device 13 are connected by feeder line L3, terminal device 13 and terminal device 14 are connected by feeder line L4, and terminal device 14 and terminal device 15 are connected by feeder line L5.

[0017] In this manner, in the communication system 1, the terminal devices 11, 12, 13, 14, and 15 are connected in this order downstream from the management device 5 on the communication path starting from the management device 5.

[0018] A communication address is set in each of the terminal devices 11 to 15 for bus communication with the management device 5. The communication address is a communication address assigned by the management device 5 to each of the terminal devices 11 to 15. In this embodiment, the communication address of each of the terminal devices 11 to 15 is set using the management device 5, the terminal devices 11 to 15, and the feeder lines L1 to L5.

[0019] Hereinafter, some or all of the multiple terminal devices 11 to 15 may be referred to as terminal devices 10. The number of the multiple terminal devices 10 is not limited to five, and may be two to four or six or more. The connection order of the multiple terminal devices 11 to 15 may be predetermined.

[0020] [Configuration of Terminal Device] The configuration of the terminal device according to the embodiment will be described with reference to FIGS. 2 to 5. FIG.

[0021] FIG. 2 is a diagram showing a circuit configuration of the terminal device 10 according to the embodiment.

[0022] As shown in FIG. 2, the terminal device 10 includes connectors C1 and C2 connected to the two feeder wirings, respectively, a communication circuit unit 60, a control unit 50, and a diode 81 that can serve as a bypass circuit.

[0023] The control unit 50 controls the device body and communication circuit unit 60 of the terminal device 10. For example, the control unit 50 is connected to the communication circuit unit 60, the input terminal E1 of the connector C1, and the output terminal E2 of the connector C2. The control unit 50 controls the operation of the communication circuit unit 60 based on a signal input to the input terminal E1. After controlling the operation of the communication circuit unit 60, the control unit 50 outputs a predetermined signal via the output terminal E2.

[0024] The control unit 50 includes a logic circuit 51, a linear regulator (LDO: Low Dropout) 52, a microprocessor 55, and a voltage signal switching circuit 58. The detailed configuration of the control unit 50 will be described later.

[0025] The communication circuit unit 60 has a transceiver integrated circuit (transceiver IC) 65 and multiple photocouplers 61, 62, and 63. One end of the photocoupler 61 is connected to a transmission terminal of the transceiver IC 65, and the other end is connected to the microprocessor 55. One end of the photocoupler 62 is connected to a control terminal of the transceiver IC 65, and the other end is connected to the microprocessor 55. One end of the photocoupler 63 is connected to a reception terminal of the transceiver IC 65, and the other end is connected to the microprocessor 55.

[0026] The transceiver IC 65 is an IC (Integrated Circuit) for communicating between the management device 5 and the multiple terminal devices 11 to 15, and performs bus communication based on a communication standard such as RS485. The transceiver IC 65 receives communication data output from the management device 5 and outputs it to the microprocessor 55 via a photocoupler 63. The transceiver IC 65 also receives a signal output from the microprocessor 55 via a photocoupler 61 and transmits it to the management device 5. Transmission and reception by the transceiver IC 65 are switched by a control signal input from the microprocessor 55 to the transceiver IC 65 via a photocoupler 62.

[0027] Each of the connectors C1 and C2 is, for example, a receptacle connector, and is fixed to the device body of the terminal device 10. The connector C1 has communication terminals Pa and Pb, a ground terminal G, and an input terminal E1. The connector C2 has communication terminals Pa and Pb, a ground terminal G, and an output terminal E2.

[0028] The communication terminals Pa and Pb are a pair of terminals for differential signals used when the terminal device 10 performs bus communication with the management device 5. Communication signals (specifically, differential signals) for communicating with the outside are input and output to and from the communication terminals Pa and Pb. The communication terminals Pa and Pb are connected to the transceiver IC 65 via internal wiring of the terminal device 10.

[0029] For example, the communication terminal Pa of the connector C1 is connected to the transceiver IC 65 via one internal wiring a1 that is conductive to the communication terminal Pa, and is also connected to the communication terminal Pa of the connector C2 via the other internal wiring a2 that is conductive to the communication terminal Pa. The communication terminal Pb of the connector C1 is connected to the transceiver IC 65 via one internal wiring b1 that is conductive to the communication terminal Pb, and is also connected to the communication terminal Pb of the connector C2 via the other internal wiring b2 that is conductive to the communication terminal Pb.

[0030] The communication data output from the management device 5 is transmitted to the transceiver IC 65 via the feed wiring, the communication terminals Pa and Pb of the connector C1, and one of the internal wirings a1 and b1. The communication data output from the management device 5 is also transmitted to the communication terminals Pa and Pb of the connector C2 via the feed wiring, the communication terminals Pa and Pb of the connector C1, and the other of the internal wirings a2 and b2.

[0031] The ground terminal G is a terminal connected to the ground wires in the feeder wirings L1 to L5 and is set to ground potential. For example, the ground terminal G of the connector C1 is connected to the signal ground via one internal wiring g1 that is electrically connected to the ground terminal G, and is also connected to the ground terminal G of the connector C2 via the other internal wiring g2 that is electrically connected to the ground terminal G.

[0032] The input terminal E1 and the output terminal E2 are terminals used when setting the communication address of the terminal device 10. The input terminal E1 and the output terminal E2 are each connected to the control unit 50 via internal wiring of the terminal device 10.

[0033] For example, the input terminal E1 is connected to the control unit 50 and the diode 81 via an internal wiring e1 that is conductive to the input terminal E1. The output terminal E2 is connected to the control unit 50 and the diode 81 via an internal wiring e2 that is conductive to the output terminal E2. The diode 81 is an example of a semiconductor element having a pn junction.

[0034] 2, the anode of the diode 81 is connected to the input terminal E1, and the cathode is connected to the output terminal E2. In other words, the diode 81 is disposed on the path connecting the input terminal E1 and the output terminal E2, and is connected in parallel to the control unit 50.

[0035] Here, the connection relationship between the input terminals E1 and the output terminals E2 of the multiple terminal devices 10 included in the communication system 1 will be specifically described.

[0036] FIG. 3 is a diagram showing the connection relationships of a plurality of terminal devices 10 included in the communication system 1. As shown in FIG.

[0037] 3, the management device 5 is connected via a feeder line L1 to an input terminal E1 of a connector C1 of the terminal device 11. The ground terminal G of the management device 5 is connected to both the ground terminal G of the terminal device 11 and the input terminal E1.

[0038] The terminal device 11 is the first terminal device closest to the management device 5 in the communication path starting from the management device 5. The input terminal E1 and output terminal E2 of the terminal device 11 are connected to the control unit 50 of the terminal device 11. A diode 81 is arranged on the path connecting the input terminal E1 and the output terminal E2. The output terminal E2 of the terminal device 11 is connected to the input terminal E1 of the terminal device 12 via the feeder wiring L2.

[0039] Terminal device 12 is the second terminal device that is second closest to management device 5 in the communication path starting from management device 5. The input terminal E1 and output terminal E2 of terminal device 12 are connected to the control unit 50 of terminal device 12. A diode 81 is disposed on the path connecting input terminal E1 and output terminal E2. The output terminal E2 of terminal device 12 is connected to the input terminal E1 of terminal device 13 via feeder wiring L3.

[0040] Terminal device 13 is the third terminal device that is third closest to management device 5 in the communication path starting from management device 5. The input terminal E1 and output terminal E2 of terminal device 13 are connected to the control unit 50 of terminal device 13. A diode 81 is arranged on the path connecting the input terminal E1 and the output terminal E2. The output terminal E2 of terminal device 13 is connected to the input terminal E1 of terminal device 14 via feeder wiring L4.

[0041] Terminal device 14 is the fourth terminal device that is fourth closest to management device 5 on the communication path starting from management device 5. The input terminal E1 and output terminal E2 of terminal device 14 are connected to the control unit 50 of terminal device 14. A diode 81 is disposed on the path connecting input terminal E1 and output terminal E2. The output terminal E2 of terminal device 14 is connected to the input terminal E1 of terminal device 15 via feeder wiring L5.

[0042] The terminal device 15 is the terminal device at the end of a communication path starting from the management device 5, and is the farthest from the management device 5. The input terminal E1 and output terminal E2 of the terminal device 15 are connected to the control unit 50 of the terminal device 15. A diode 81 is arranged on the path connecting the input terminal E1 and the output terminal E2. A termination resistor may be connected to the output terminal E2 of the terminal device 15.

[0043] In this way, among the multiple terminal devices 10 included in the communication system 1, the management device 5 is connected to the input terminal E1 of the terminal device 10 closest to the management device 5, and the output terminal E2 of that terminal device 10 is connected to the input terminal E1 of the next terminal device 10 downstream from itself.

[0044] The control unit 50 accepts the communication address transmitted from the management device 5 to the terminal device 10 and sets the communication address as its own communication address. The configurations of the control unit 50, communication circuit unit 60, input terminal E1, and output terminal E2 for setting the communication address will be described below.

[0045] 2, the control unit 50 is connected to the communication circuit unit 60, the input terminal E1, and the output terminal E2. A voltage signal that permits or prohibits the setting of a communication address is input to the input terminal E1. The voltage signal input to the input terminal E1 is transmitted to the control unit 50 via internal wiring e1. The control unit 50 sets the communication address of the terminal device 10 based on the voltage signal input to the input terminal E1.

[0046] For example, when the input voltage signal is a voltage signal that permits the setting of a communication address, the control unit 50 activates the communication circuit unit 60. When the input voltage signal is a voltage signal that prohibits the setting of a communication address, the control unit 50 does not activate the communication circuit unit 60.

[0047] The voltage signal that does not permit the setting of a communication address is a signal that has a predetermined voltage value and indicates a predetermined logical state. The predetermined voltage value is, for example, 12 V. The voltage signal that permits the setting of a communication address is a signal that indicates a logical state that is the inverse of the predetermined logical state and has a voltage value lower than the predetermined voltage value. The voltage value lower than the predetermined voltage value is, for example, ground potential or 0 V.

[0048] In the following, a signal that does not allow the setting of a communication address and indicates a predetermined logical state will be referred to as a high signal, and a signal that allows the setting of a communication address and indicates a logical state that is the inverse of the predetermined logical state will be referred to as a low signal.

[0049] The control unit 50 controls whether or not the communication circuit unit 60 is able to communicate by switching whether or not to supply a drive voltage to the transceiver IC 65 of the communication circuit unit 60 based on the voltage signal input via the input terminal E1.

[0050] As described above, the control unit 50 includes the logic circuit 51 , the linear regulator 52 , the microprocessor 55 and the voltage signal switching circuit 58 .

[0051] The logic circuit 51 is a logic inversion circuit including a bipolar transistor such as a PNP transistor Tr. The emitter of the PNP transistor Tr is connected to a predetermined voltage source (12 V), and the base is connected to the input terminal E1. The base and emitter are connected to each other via a resistor. The collector of the PNP transistor Tr is connected to ground via a resistor, and is also connected to the enable terminal EN of the linear regulator 52.

[0052] The voltage input section (Vin) of the linear regulator 52 is connected to a predetermined voltage source (12 V), and the voltage output section (Vout) is connected to the transceiver IC 65. The enable terminal EN of the linear regulator 52 is connected to the logic circuit 51. The linear regulator 52 supplies a drive voltage (5 V) to the transceiver IC 65 for driving the transceiver IC 65. The transceiver IC 65 is capable of communication when the drive voltage is supplied, but is unable to communicate when the drive voltage is not supplied. Note that the voltage value of the drive voltage is different from the voltage value of the predetermined voltage source described above and is set to a value lower than the voltage value of the predetermined voltage source.

[0053] 4 is a diagram showing the relationship between the potential of the input terminal E1, the output of the logic circuit 51, the presence or absence of a drive voltage output from the linear regulator 52, and the availability of communication by the transceiver IC 65. The diagram also shows the connection status of the input terminal E1.

[0054] For example, if the connection state of the input terminal E1 is open or the potential is high, the output of the logic circuit 51 becomes low. As a result, no drive voltage is output from the linear regulator 52 to the transceiver IC 65, and the communication circuit unit 60 becomes unable to communicate. In other words, the terminal device 10 becomes unable to set a communication address.

[0055] On the other hand, when the potential of the input terminal E1 is low, the output of the logic circuit 51 becomes high. As a result, a drive voltage is output from the linear regulator 52 to the transceiver IC 65, and the communication circuit unit 60 becomes capable of communication. In other words, the terminal device 10 becomes capable of setting a communication address.

[0056] As described above, the control unit 50 controls whether or not communication is permitted through the communication circuit unit 60. The control unit 50 acquires the communication address transmitted from the management device 5 via the communication circuit unit 60, and sets the acquired communication address as the communication address of this terminal device 10. The communication address set by the control unit 50 is saved in the memory unit 56. The memory unit 56 is configured with a non-volatile storage device such as a flash memory, and the communication address is retained in the memory unit 56 even after the power to the terminal device 10 is turned off.

[0057] The control unit 50 controls the communication circuit unit 60 to set the communication address, and then outputs a predetermined signal via the output terminal E2. Specifically, the control unit 50 uses the voltage signal switching circuit 58 to output a predetermined voltage signal from the output terminal E2.

[0058] The voltage signal switching circuit 58 is a circuit that switches the voltage signal output from the output terminal E2, and is composed of, for example, a photocoupler. The light-emitting element of the photocoupler that constitutes the voltage signal switching circuit 58 is connected to the microprocessor 55. The light-receiving element of the photocoupler that constitutes the voltage signal switching circuit 58 has one end connected to the output terminal E2 and the other end connected to ground. A voltage source having a predetermined voltage value (12 V) is connected via a resistive element to the path connecting one end of the light-receiving element of the photocoupler and the output terminal E2. The control unit 50 uses the voltage signal switching circuit 58 to switch the voltage signal output from the output terminal E2.

[0059] FIG. 5 is a diagram showing the relationship between the setting state of the communication address, the on / off state of the voltage signal switching circuit, the potential of the output terminal E2, and the potential of the input terminal E1 of the next terminal device 10.

[0060] In the figure, when the communication address is "254", it indicates that the communication address has not been set, and when the communication address is any number between "1" and "253", it indicates that the communication address has been set. In this example, the communication address "254" is set for the terminal device 10 in its initial state, such as at the time of product shipment. Before an individual communication address is set for the terminal device 10, the terminal device 10 communicates with the management device 5 using the communication address "254" and obtains the individual communication address sent from the management device 5. Note that the number "254", which indicates that the communication address has not been set, is merely an example, and other numbers may be used.

[0061] If a communication address has not been set for the terminal device 10, i.e., if the communication address setting has not been completed, the microprocessor 55 turns the voltage signal switching circuit 58 off. When the voltage signal switching circuit 58 is off, the potential of the output terminal E2 becomes high due to a predetermined voltage source (12 V). This causes a high signal to be output from the output terminal E2, and the potential of the input terminal E1 of the next terminal device 10 becomes high. In other words, the next terminal device 10 is placed in a state where it is not possible to set a communication address.

[0062] On the other hand, when the setting of the communication address of the terminal device 10 is completed, the microprocessor 55 turns on the voltage signal switching circuit 58. When the voltage signal switching circuit 58 is on, the potential of the output terminal E2 becomes low. As a result, a low signal is output from the output terminal E2, and the potential of the input terminal E1 of the next terminal device 10 becomes low. In other words, the next terminal device 10 is now in a state where a communication address can be set.

[0063] Furthermore, within the terminal device 10, the voltage signal switching circuit 58 and the logic circuit 51 are connected via a diode 81. Therefore, when the setting of the communication address is completed, if the voltage signal switching circuit 58 is in the on state and the potential becomes low, the input voltage of the logic circuit 51 becomes low via the diode 81, and the control unit 50 can operate the communication circuit unit 60. Therefore, even if a malfunction occurs in the preceding (upstream) terminal device 10, such as the power not being turned on, and no signal is input to the input terminal E1, communication with the management device 5 can be performed via the preceding terminal device 10. As a result, even if a malfunction occurs in a specific terminal device among the multiple terminal devices 10, for example, communication can be performed with the next terminal device connected to the specific terminal device.

[0064] That is, when the setting of the communication address is completed, the control unit 50 outputs a voltage signal via the output terminal E2 that permits the setting of the communication address. On the other hand, when the setting of the communication address is not completed, the control unit 50 outputs a voltage signal via the output terminal E2 that prohibits the setting of the communication address. The control unit 50 of each terminal device 10 controls whether or not the setting of the communication address in the next terminal device 10 is permitted as described above, and thus the communication addresses are set for the multiple terminal devices 10 one by one in order from upstream to downstream.

[0065] [Example of Setting a Communication Address] An example of setting a communication address will be described with reference to FIG.

[0066] FIG. 6 is a diagram showing an example of setting a communication address of the terminal device 10 according to the embodiment.

[0067] In the figure, a management device 5, a terminal device 11, and a terminal device 12 included in a communication system 1 are shown.

[0068] 6A, the input terminal E1 of the terminal device 11 is at ground potential. In this case, only the management device 5 and the terminal device 11 are able to communicate. Since the terminal device 11 has not yet completed setting its own communication address, it outputs a high signal from its output terminal E2 to the input terminal E1 of the terminal device 12. As a result, the terminal device 12, which is located downstream (later stage) of the terminal device 11, is unable to communicate with the management device 5, i.e., is unable to set its communication address.

[0069] The terminal device 11 communicates with the management device 5 using the initially set communication address "254." The terminal device 11 accepts the address change command and communication address directed to the communication address "254" sent from the management device 5, and sets the sent communication address as its own communication address. In this example, the communication address "1" sent from the management device 5 is set in the terminal device 11. When the setting of the communication address is complete, the terminal device 11 outputs a low signal to the input terminal E1 of the next terminal device 12 via the output terminal E2.

[0070] When the potential of the input terminal E1 of the terminal device 12 is low, as shown in (b) of Figure 6, only the management device 5, terminal device 11, and terminal device 12 are able to communicate. Since the terminal device 12 has not yet completed setting its own communication address, it outputs a high signal from its output terminal E2 to the input terminal E1 of the terminal device 13. As a result, the terminal device 13, which is located downstream of the terminal device 12, is unable to communicate with the management device 5, i.e., is unable to set its communication address.

[0071] The terminal device 12 communicates with the management device 5 using the initially set communication address "254." The terminal device 12 accepts the address change command and communication address directed to the communication address "254" sent from the management device 5, and sets the sent communication address as its own communication address. In this example, the communication address "2" sent from the management device 5 is set in the terminal device 12. Note that the communication address "1" has already been set for the terminal device 11, so it ignores the address change command sent from the management device 5. When the communication address setting is complete, the terminal device 12 outputs a low signal to the input terminal E1 of the next terminal device 13 via the output terminal E2.

[0072] When the potential of the input terminal E1 of the terminal device 13 is low, only the management device 5, the terminal device 11, the terminal device 12, and the terminal device 13 (not shown) are able to communicate, as shown in (c) of Fig. 6. Thereafter, these operations are repeated according to the number of terminal devices 10, and different communication addresses are set for all the terminal devices 10.

[0073] As described above, by setting the communication address of the first terminal device 11 connected to the management device 5 to "1" and setting communication addresses in consecutive order from there, it is possible to appropriately manage addresses in the communication system 1. For example, the management device 5 checks the communication addresses of all terminal devices 10, and if the largest number in the set communication addresses reaches a predetermined set number, it can be determined that address setting has been completed without any problems. On the other hand, if the largest number in the set communication addresses does not reach the predetermined set number, it can be determined that a malfunction has occurred in one of the multiple terminal devices 10.

[0074] [First Modification of the Embodiment] A terminal device 10 according to a first modification of the embodiment will be described. Fig. 7 is a diagram showing the circuit configuration of the terminal device 10 according to the first modification of the embodiment. In the first modification, a transistor 82 is arranged in the circuit of the terminal device 10, instead of a diode 81. The transistor 82 is an example of a semiconductor element having a pn junction.

[0075] The terminal device 10 of the first modification includes connectors C1 and C2 connected to the feeder wiring, a communication circuit unit 60, a control unit 50A, and a transistor 82 that can function as a bypass circuit.

[0076] The configurations of the connectors C1 and C2 and the communication circuit unit 60 in Modification 1 are substantially the same as those in the embodiment. In Modification 1, as in the embodiment, the control unit 50A controls whether or not the communication circuit unit 60 is able to communicate by switching between supplying and not supplying a drive voltage to the transceiver IC 65 of the communication circuit unit 60.

[0077] In the first modification, a transistor 82 is used instead of the diode 81 of the embodiment. Furthermore, the transistor 82 of the first modification is not directly connected to the input terminal E1, but is connected to the input terminal E1 via the logic circuit 51. The transistor 82 is, for example, a PNP transistor.

[0078] The control unit 50A includes a logic circuit 51, a linear regulator 52, a microprocessor 55, and a voltage signal switching circuit 58.

[0079] The logic circuit 51 is a logic inversion circuit including a bipolar transistor such as a PNP transistor Tr. The emitter of the PNP transistor Tr is connected to a predetermined voltage source (12 V), and the base is connected to the input terminal E1. The base and emitter are connected to each other via a resistor. The collector of the PNP transistor Tr is connected to ground via a resistor and also to the enable terminal EN of the linear regulator 52. The collector of the PNP transistor Tr in the first modification is connected to a transistor 82, which can serve as a bypass circuit.

[0080] 7, the emitter of transistor 82, which is a PNP transistor, is connected to a predetermined voltage source (12 V), and the base is connected to a path connecting voltage signal switching circuit 58 and output terminal E2. The collector of transistor 82 is connected to the collector of PNP transistor Tr of logic circuit 51. That is, one end of transistor 82 is connected to input terminal E1 via PNP transistor Tr, and the other end is connected to output terminal E2.

[0081] In the terminal device 10 of this modified example, when the communication address setting is complete, the voltage signal switching circuit 58 is turned on and the potential becomes low, turning on the transistor 82, outputting a drive voltage from the linear regulator 52 to the transceiver IC 65, and the control unit 50A can operate the communication circuit unit 60. Therefore, even if a malfunction occurs in the preceding terminal device 10, such as when the power does not turn on, and no signal is input to the input terminal E1, communication with the management device 5 can be performed via the preceding terminal device 10. As a result, even if a malfunction occurs in a specific terminal device among the multiple terminal devices 10, for example, communication can be performed with the next terminal device connected to the specific terminal device.

[0082] Although the above example shows the case where a PNP transistor is used as the transistor 82, the present invention is not limited to this. For example, the circuit including the transistor 82 may be realized by another circuit using an NPN transistor.

[0083] [Second Modification of the Embodiment] A terminal device 10 according to a second modification of the embodiment will be described. Fig. 8 is a diagram showing the circuit configuration of the terminal device 10 according to the second modification of the embodiment. In the second modification, the possibility of communication of the communication circuit unit 60 is controlled by switching a control signal that controls transmission and reception of the transceiver IC 65.

[0084] The terminal device 10 of the second modification includes connectors C1 and C2 connected to the feed wiring, a communication circuit unit 60, a control unit 50B, and a diode 81 that can serve as a bypass circuit.

[0085] The configurations of the connectors C1 and C2, the communication circuit section 60, and the diode 81 of the second modification are substantially the same as those of the embodiment.

[0086] The control unit 50B has a logic circuit 51, a linear regulator 52, a microprocessor 55, and a voltage signal switching circuit 58. The enable terminal EN of the linear regulator 52 in the second modification is connected to a predetermined voltage source, and a drive voltage is constantly supplied to the transceiver IC 65.

[0087] The logic circuit 51 is a circuit including a bipolar transistor such as an NPN transistor Tr1. The base of the NPN transistor Tr1 is connected to the input terminal E1. The base and collector of the NPN transistor Tr1 are connected to each other via a resistor element. The collector is connected to a predetermined voltage source (5 V).

[0088] In the second modification, the emitter of the NPN transistor Tr 1 is connected to a path connecting the control terminal of the transceiver IC 65 and the photocoupler 62 .

[0089] For example, if the connection state of the input terminal E1 is open or the potential is high, the NPN transistor Tr1 is turned on, and the control terminal of the transceiver IC 65 becomes high. As a result, the transceiver IC 65 enters the transmission mode, and the communication circuit unit 60 becomes unable to receive. In other words, the terminal device 10 enters a state in which it is impossible to set a communication address.

[0090] On the other hand, when the potential of the input terminal E1 is low, the NPN transistor Tr1 is turned off and the control terminal of the transceiver IC 65 goes low. As a result, the transceiver IC 65 becomes capable of transmitting and receiving (or at least receiving) signals based on the control signal output from the microprocessor 55. In other words, the terminal device 10 becomes capable of setting a communication address.

[0091] As described above, by controlling whether or not communication is possible through the communication circuit unit 60, the communication address transmitted from the management device 5 can be set as the communication address of the terminal device 10.

[0092] Furthermore, in the terminal device 10 of this modified example, the voltage signal switching circuit 58 and the logic circuit 51 are connected via a diode 81. Therefore, when the communication address setting is complete, if the voltage signal switching circuit 58 is in the on state and the potential becomes low, the input voltage of the logic circuit 51 becomes low via the diode 81, and the control unit 50B can operate the communication circuit unit 60. Therefore, even if a malfunction occurs in the preceding terminal device 10, such as the power not being turned on, and no signal is input to the input terminal E1, communication with the management device 5 can be performed via the preceding terminal device 10. As a result, even if a malfunction occurs in a specific terminal device among the multiple terminal devices 10, for example, communication can be performed with the next terminal device connected to the specific terminal device.

[0093] Although the above example shows the logic circuit 51 using the NPN transistor Tr1, the present invention is not limited to this example and the logic circuit 51 may be realized by other circuits using PNP transistors, for example.

[0094] [Third Modification of the Embodiment] A terminal device 10 according to a third modification of the embodiment will be described. Fig. 9 is a diagram showing the circuit configuration of the terminal device 10 according to the third modification of the embodiment. In the third modification, the photocoupler 63 connected to the receiving terminal of the transceiver IC 65 is switched between operable and inoperable to control whether or not communication is possible in the communication circuit unit 60.

[0095] The terminal device 10 of the third modification includes connectors C1 and C2 connected to the feed wiring, a communication circuit unit 60, a control unit 50C, and a diode 81 that can serve as a bypass circuit.

[0096] The configurations of the connectors C1 and C2, the communication circuit section 60, and the diode 81 of the third modification are substantially the same as those of the embodiment.

[0097] The control unit 50C includes a logic circuit 51, a linear regulator 52, a microprocessor 55, and a voltage signal switching circuit 58. The enable terminal EN of the linear regulator 52 in the third modification is connected to a predetermined voltage source, and a drive voltage is constantly supplied to the transceiver IC 65.

[0098] The logic circuit 51 is a logic inversion circuit including a bipolar transistor such as a PNP transistor Tr. The emitter of the PNP transistor Tr is connected to a predetermined voltage source (e.g., 5 V), and the base of the PNP transistor Tr is connected to the input terminal E1. The base and emitter of the PNP transistor Tr are connected to each other via a resistor. The collector of the PNP transistor Tr is connected to a switch element disposed on a path connecting the receiving terminal of the transceiver IC 65 and the light-emitting element of the photocoupler 62.

[0099] For example, if the connection state of the input terminal E1 is open or the potential is high, the potential of the collector of the PNP transistor Tr remains low. As a result, the communication signal output from the receiving terminal of the transceiver IC 65 to the microprocessor 55 is blocked by the photocoupler 63, and the communication circuit unit 60 becomes unable to communicate. In other words, the terminal device 10 becomes unable to set a communication address.

[0100] On the other hand, when the potential of the input terminal E1 is low, the potential of the collector of the PNP transistor Tr becomes high. As a result, the communication signal output from the receiving terminal of the transceiver IC 65 to the microprocessor 55 is not blocked by the photocoupler 63, and the communication circuit unit 60 becomes capable of communication. In other words, the terminal device 10 is now in a state where a communication address can be set.

[0101] As described above, by controlling whether or not communication is possible through the communication circuit unit 60, the communication address transmitted from the management device 5 can be set as the communication address of the terminal device 10.

[0102] Furthermore, in the terminal device 10 of this modified example, the voltage signal switching circuit 58 and the logic circuit 51 are connected via a diode 81. Therefore, when the communication address setting is complete, if the voltage signal switching circuit 58 is turned on and its potential becomes low, the input voltage of the logic circuit 51 becomes low via the diode 81, and the control unit 50C can operate the communication circuit unit 60. Therefore, even if a malfunction occurs in the preceding terminal device 10, such as the power not being turned on, and no signal is input to the input terminal E1, communication with the management device 5 can be performed via the preceding terminal device 10. As a result, even if a malfunction occurs in a specific terminal device among the multiple terminal devices 10, for example, communication can be performed with the next terminal device connected to the specific terminal device.

[0103] (Summary) Hereinafter, a terminal device according to one aspect of the present disclosure and a communication system according to another aspect will be described as examples.

[0104] The terminal device 10 in Example 1 is a terminal device in which a communication address is set. The terminal device 10 includes communication terminals Pa and Pb through which communication signals for communicating with the management device 5 are input and output, a communication circuit unit 60 connected to the communication terminals Pa and Pb, an input terminal E1 and an output terminal E2, control units 50, 50A, 50B, or 50C connected to the communication circuit unit 60, the input terminal E1, and the output terminal E2, respectively, and a diode 81 or a transistor 82 arranged on a path connecting the input terminal E1 and the output terminal E2. The control unit 50, 50A, 50B, or 50C controls the operation of the communication circuit unit 60 based on a signal input to the input terminal E1, and then outputs a predetermined signal via the output terminal E2.

[0105] In this way, by arranging the diode 81 or the transistor 82 on the path connecting the input terminal E1 and the output terminal E2, the terminal device 10 can operate the communication circuit unit 60 by itself even if a malfunction occurs, such as the power not being turned on in the preceding terminal device 10. As a result, even if a malfunction occurs in a specific terminal device among the multiple terminal devices 10, communication can be performed with the next terminal device connected to the specific terminal device.

[0106] The terminal device 10 of Example 2 is the terminal device described in Example 1, and a diode 81 is connected in parallel to the control unit. The anode of the diode 81 may be connected to the input terminal E1, and the cathode may be connected to the output terminal E2.

[0107] In this way, by connecting the diode 81 in parallel to the control unit, the terminal device 10 can operate the communication circuit unit 60 by itself even if a malfunction occurs, such as the power not being turned on in the previous terminal device 10. As a result, even if a malfunction occurs in a specific terminal device among the multiple terminal devices 10, communication can be performed with the next terminal device connected to the specific terminal device.

[0108] The terminal device 10 of Example 3 is the terminal device described in Example 1 or 2, and the control unit may control the operation of the communication circuit unit 60 to obtain a communication address sent from the management device 5 via the communication circuit unit 60, and set the communication address as the communication address of the terminal device 10.

[0109] In this way, the control unit obtains the communication address sent from the management device 5 and sets the communication address as the communication address of the terminal device 10, thereby making it possible to appropriately set a communication address for each of the multiple terminal devices 10.

[0110] The terminal device 10 of Example 4 is the terminal device described in Example 3, and a signal that permits or prohibits the setting of a communication address is input to the input terminal E1. The control unit may enable communication by the communication circuit unit 60 when the signal is a voltage signal that permits the setting of a communication address, and may prohibit communication by the communication circuit unit 60 when the signal is a voltage signal that prohibits the setting of a communication address.

[0111] In this way, by enabling or disabling communication by the communication circuit unit 60 in response to the voltage signal, it is possible to set an individual communication address for each of the multiple terminal devices 10 .

[0112] The terminal device 10 of Example 5 is the terminal device described in Example 3 or 4, and the control unit may output a signal via output terminal E2 permitting the setting of the communication address when the setting of the communication address has been completed, and may output a signal via output terminal E2 disallowing the setting of the communication address when the setting of the communication address has not been completed.

[0113] In this way, by outputting a signal via output terminal E2 to allow or disallow the setting of the communication address depending on whether or not the setting of the communication address has been completed, it is possible to set an individual communication address for each of multiple terminal devices 10.

[0114] The terminal device 10 of Example 6 is the terminal device described in Example 4 or 5, and the signal that does not allow the setting of a communication address may be a signal that indicates a predetermined logic state having a predetermined voltage value, and the signal that allows the setting of a communication address may be a signal that indicates a logic state that is the inverse of the predetermined logic state.

[0115] In this way, by selectively using a signal indicating a predetermined logical state and a signal indicating a logical state that is the inverse of the predetermined logical state, it is possible to easily set a communication address for each of the multiple terminal devices 10.

[0116] The terminal device 10 of Example 7 is the terminal device described in any one of Examples 1 to 6, and further includes a storage unit 56 that stores the communication address set by the control unit. The communication address may be retained in the storage unit 56 even after the terminal device 10 is powered off.

[0117] This configuration eliminates the need to set a communication address every time the power is turned on, thereby reducing the effort required to set a communication address.

[0118] The terminal device 10 of Example 8 is a terminal device described in any of Examples 1 to 7, and the control unit 50 or 50A may control whether or not the communication circuit unit 60 can communicate by switching whether or not to supply a driving voltage to the transceiver IC 65 of the communication circuit unit 60.

[0119] As described above, by controlling whether or not communication is possible through the communication circuit unit 60, the communication address transmitted from the management device 5 can be set as the communication address of the terminal device 10.

[0120] The terminal device 10 of Example 9 is a terminal device described in any of Examples 1 to 7, and the control unit 50B may control whether or not communication is possible through the communication circuit unit 60 by switching a control signal that controls transmission and reception of the transceiver IC 65 of the communication circuit unit 60.

[0121] As described above, by controlling whether or not communication is possible through the communication circuit unit 60, the communication address transmitted from the management device 5 can be set as the communication address of the terminal device 10.

[0122] The terminal device 10 of Example 10 is a terminal device described in any of Examples 1 to 7, and the control unit 50C may control whether or not communication is possible through the communication circuit unit 60 by switching whether or not the light-emitting element of the photocoupler 63 connected to the receiving terminal of the transceiver IC 65 of the communication circuit unit 60 is activated.

[0123] As described above, by controlling whether or not communication is possible through the communication circuit unit 60, the communication address transmitted from the management device 5 can be set as the communication address of the terminal device 10.

[0124] The communication system 1 of Example 11 is a communication system including a plurality of terminal devices 10 and a management device 5. The plurality of terminal devices 10 includes at least a first terminal device 11, a second terminal device 12, and a third terminal device 13, and are bus-connected to the management device 5 via their respective communication terminals Pa and Pb. The input terminal E1 of the first terminal device 11 is connected to the management device 5. The output terminal E2 of the first terminal device 11 is connected to the input terminal E1 of the second terminal device 12. The output terminal E2 of the second terminal device 12 is connected to the input terminal E1 of the third terminal device 13.

[0125] According to this configuration, it is possible to appropriately set a communication address for each of the terminal devices 11 to 13 using the management device 5 and the terminal devices 11 to 13.

[0126] (Other Embodiments) Although the embodiments and modifications thereof have been described above, the present disclosure is not limited to the above-described embodiments and modifications.

[0127] For example, the terminal device 10 of the embodiment may be a communication device itself. In this case, the communication system 1 may be configured such that the management device 5 controls the main body of the moving machine or the main body of the electrical machine via the terminal device 10. Furthermore, the terminal device 10 may be an address setting device that only has the function of setting a communication address.

[0128] In the above embodiment, an example is shown in which the voltage signal switching circuit 58 is provided outside the microprocessor 55, but this is not limiting and the voltage signal switching circuit 58 may be provided inside the microprocessor 55.

[0129] In the above embodiment, an example was given of a terminal device that can set a communication address to a terminal device other than the specified terminal device even if a malfunction occurs in the specified terminal device, but this is not limited to this, and the terminal device may also be provided as a device that can easily set a communication address.

[0130] In this case, for example, the terminal device may include a communication terminal through which a communication signal for communicating with a management device is input and output, a communication circuit unit connected to the communication terminal, an input terminal, and an output terminal, and a control unit connected to the communication circuit unit, the input terminal, and the output terminal, respectively, for controlling the operation of the communication circuit unit based on a signal input to the input terminal and then outputting a predetermined signal via the output terminal. The control unit may be a device that controls the operation of the communication circuit unit to obtain a communication address transmitted from the management device via the communication circuit unit and set the communication address as the communication address of the terminal device.

[0131] In the above embodiment, an example is shown in which a communication address is set for each terminal device 10, but the correspondence between the communication address of each terminal device 10 and its location may be performed separately after the communication address is set. For example, the communication address of each terminal device 10 can be associated with its location by outputting a control signal including a predetermined communication address from the management device 5 and turning on a pilot lamp or the like provided on the predetermined terminal device 10.

[0132] In the above-described embodiments, each component of the control device may be configured with dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU (Central Processing Unit) or a processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0133] Each component may be a circuit (or integrated circuit). Multiple components may form a single circuit as a whole, or each may be a separate circuit. Each circuit may be a general-purpose circuit or a dedicated circuit.

[0134] Furthermore, a comprehensive or specific aspect of the present disclosure may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM. Alternatively, the present disclosure may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a non-transitory recording medium. For example, the present disclosure may be realized as a program for causing a computer to execute control performed by a control device or the like provided in each component of a communication system.

[0135] Furthermore, the order of the multiple processes in the operation of the communication system described in the above embodiment is an example. The order of the multiple processes may be changed, or the multiple processes may be executed in parallel.

[0136] In addition, this disclosure also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art would think of, or forms realized by arbitrarily combining the components and functions of each embodiment within the scope of this disclosure.

[0137] The terminal device and communication system of the present disclosure can set a communication address to a terminal device other than the terminal device even if a malfunction occurs in a specific terminal device among multiple terminal devices. In this way, the terminal device and communication system of the present disclosure are industrially useful.

[0138] REFERENCE SIGNS LIST 1 Communication system 5 Management device 10, 11, 12, 13, 14, 15 Terminal devices 50, 50A, 50B, 50C Control unit 51 Logic circuit 52 Linear regulator 55 Microprocessor 56 Memory unit 58 Voltage signal switching circuit 60 Communication circuit unit 61, 62, 63 Photocoupler 65 Transceiver IC 81 Diode 82 Transistor a1, a2, b1, b2, g1, g2, e1, e2 Internal wiring C1, C2 Connector E1 Input terminal E2 Output terminal G Ground terminal L1, L2, L3, L4, L5 Feed wiring Pa, Pb Communication terminal Tr PNP transistor Tr1 NPN transistor

Claims

1. A terminal device in which a communication address is set, comprising: a communication terminal for inputting and outputting communication signals for communicating with a management device; a communication circuit unit connected to the communication terminal; an input terminal and an output terminal; a control unit connected to the communication circuit unit, the input terminal and the output terminal, respectively, for controlling the operation of the communication circuit unit based on a signal input to the input terminal, and then outputting a predetermined signal via the output terminal; and a diode or transistor arranged on a path connecting the input terminal and the output terminal.

2. The terminal device according to claim 1, wherein the diode is connected in parallel to the control unit, the anode of the diode is connected to the input terminal, and the cathode is connected to the output terminal.

3. The terminal device according to claim 1, wherein the control unit controls the operation of the communication circuit unit to obtain the communication address transmitted from the management device via the communication circuit unit, and sets the communication address as the communication address of the terminal device.

4. A terminal device as described in claim 3, wherein a signal permitting or disallowing the setting of the communication address is input to the input terminal, and the control unit enables communication by the communication circuit unit when the signal is a voltage signal permitting the setting of the communication address, and disallows communication by the communication circuit unit when the signal is a voltage signal disallowing the setting of the communication address.

5. The terminal device according to claim 3, wherein the control unit outputs a signal via the output terminal to permit setting of the communication address when setting of the communication address is complete, and outputs a signal via the output terminal to disallow setting of the communication address when setting of the communication address is not complete.

6. A terminal device as described in claim 4 or 5, wherein the signal that does not permit the setting of the communication address is a signal that indicates a predetermined logic state having a predetermined voltage value, and the signal that permits the setting of the communication address is a signal that indicates a logic state that is the inverse of the predetermined logic state.

7. A terminal device according to any one of claims 1 to 5, further comprising a memory unit in which the communication address set by the control unit is stored, and the communication address is retained in the memory unit even after the power of the terminal device is turned off.

8. A terminal device according to any one of claims 1 to 5, wherein the control unit controls whether or not communication is possible for the communication circuit unit by switching on or off the supply of a drive voltage to a transceiver integrated circuit of the communication circuit unit.

9. A terminal device according to any one of claims 1 to 5, wherein the control unit controls whether or not the communication circuit unit is capable of communication by switching a control signal that controls transmission and reception of a transceiver integrated circuit of the communication circuit unit.

10. A terminal device according to any one of claims 1 to 5, wherein the control unit controls whether or not communication is possible in the communication circuit unit by switching the operation of a photocoupler connected to a receiving terminal of a transceiver integrated circuit in the communication circuit unit.

11. A communication system comprising: a plurality of terminal devices, each of which is a terminal device according to any one of claims 1 to 5; and said management device, wherein said plurality of terminal devices have at least a first terminal device, a second terminal device and a third terminal device, each of which is a terminal device, and are bus-connected to said management device via the communication terminals of said first terminal device, said second terminal device and said third terminal device, said input terminal of said first terminal device being connected to said management device, said output terminal of said first terminal device being connected to said input terminal of said second terminal device, and said output terminal of said second terminal device being connected to said input terminal of said third terminal device.

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