JP2019016919A - Communication system, communication device, and miswiring detection method - Google Patents

Abstract

To detect miswiring which causes a plurality of paths connecting a master unit and a slave units.SOLUTION: A transmission circuit 210 controls a conduction/non-conduction state between a connection point 265 to which a terminal 241 and a terminal 243 are connected and a connection point 266 to which a terminal 242 and a terminal 244 are connected to transmit data to a master unit 100. A current detection unit 263 detects a first current flowing through a communication line pair 13. A current detection unit 264 detects a second current flowing through a communication line pair 23. When the first current and the second current are equal to or higher than a predetermined threshold value in the case in which the connection point 265 and the connection point 266 are controlled to be in the conduction state, a signal output unit 280 outputs a predetermined signal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a communication system, a communication device, and a miswiring detection method.

  Currently, a communication system in which a parent device and a plurality of child devices are connected to each other by a plurality of communication line pairs is known. For example, Patent Document 1 describes a signal transmission system in which a central processing unit and a plurality of terminals are connected by a pair of transmission lines.

  In the signal transmission system described in Patent Document 1, the central processing unit transmits data to the terminal device by voltage transmission, and the terminal device transmits data to the central processing device by current transmission. In such a communication system, if there are a plurality of paths connecting the parent device and the child device, a failure or communication abnormality may occur in the parent device or the child device.

JP-A-2-210935

  However, for example, when the number of slave units is large, or when the distance between the master unit and the slave units or the distance between multiple slave units is long, multiple paths connecting the master unit and the slave units may occur due to incorrect wiring. There is. For this reason, there is a demand for a technique for detecting erroneous wiring that causes a plurality of paths connecting the parent device and the child device.

  The present invention has been made in view of the above problems, and provides a communication system, a communication device, and a miswiring detection method for detecting miswiring that generates a plurality of paths connecting a master unit and a slave unit. Objective.

In order to achieve the above object, a communication system according to the present invention includes:
A communication system comprising a master unit and a plurality of slave units, wherein the master unit and the plurality of slave units are mutually connected by a plurality of communication line pairs,
The base unit is
A receiving circuit that receives data from the plurality of slave units by detecting the presence or absence of current flowing through the communication line pair connected to the master unit among the plurality of communication line pairs;
The plurality of slave units are:
A first terminal pair to which a first communication line pair among the plurality of communication line pairs is connected;
A second terminal pair to which a second communication line pair is connected among the plurality of communication line pairs;
A first connection point to which one terminal of the first terminal pair and one terminal of the second terminal pair are connected; the other terminal of the first terminal pair; and the second terminal. A transmission circuit that transmits data to the master unit by controlling a conduction / non-conduction state between the second connection point to which the other terminal of the terminal pair is connected;
First current detection means for detecting a first current flowing in the first communication line pair;
Second current detection means for detecting a second current flowing in the second communication line pair;
When the first connection point and the second connection point are controlled to be in a conductive state when the first current and the second current are equal to or greater than a predetermined threshold, Signal output means for outputting a predetermined signal.

  In the present invention, a first connection point where one terminal of the first terminal pair and one terminal of the second terminal pair are connected, and the other terminal and the second of the first terminal pair. Flows between the first communication line pair connected to the first terminal pair when the second connection point to which the other terminal of the terminal pair is connected is connected to the second connection point. When the first current and the magnitude of the second current flowing through the second communication line pair connected to the second terminal pair are equal to or greater than a predetermined threshold, a predetermined signal is output. The Therefore, according to the present invention, it is possible to detect an erroneous wiring that causes a plurality of paths connecting the parent device and the child device.

Configuration diagram of a communication system according to Embodiment 1 of the present invention Configuration diagram of a parent device and a child device according to the first embodiment of the present invention The flowchart which shows the communication control process which the subunit | mobile_unit which concerns on Embodiment 1 of this invention performs The flowchart which shows the miswiring detection process shown in FIG. The flowchart which shows the miswiring detection process which the subunit | mobile_unit which concerns on Embodiment 2 of this invention performs The flowchart which shows the communication control process which the main | base station which concerns on Embodiment 2 of this invention performs. Configuration diagram of a communication system according to Embodiment 3 of the present invention The block diagram of the subunit | mobile_unit which concerns on Embodiment 3 of this invention

(Embodiment 1)
Embodiments of the present invention will be described with reference to the drawings. First, a communication system 1000 according to Embodiment 1 of the present invention will be described with reference to FIG. The communication system 1000 includes a parent device 100 and a plurality of child devices (child device 200, child device 300, child device 400, child device 500), and the parent device 100 and the plurality of child devices communicate with each other. is there. The communication system 1000 is an illumination system that includes, for example, an illumination control device and a plurality of illumination devices. In this case, the parent device 100 corresponds to the lighting control device, and the plurality of slave devices respectively correspond to the plurality of lighting devices.

  Master device 100 includes a DC power supply (not shown) and supplies power to a plurality of slave devices. The plurality of slave units operate with the power supplied from the master unit 100. Master device 100 transmits data to a plurality of slave devices by a voltage signal, and the plurality of slave devices transmits data to master device 100 by a current signal. In this embodiment, it is assumed that there is no broadcast and a polling method is adopted. That is, parent device 100 does not transmit data to a plurality of child devices at the same time, and the plurality of child devices transmit data to parent device 100 when receiving data from parent device 100. For this reason, the master unit 100 and the plurality of slave units do not transmit data at the same time.

  Base unit 100 and a plurality of slave units are connected to each other by a plurality of communication line pairs (communication line pair 13, communication line pair 23, communication line pair 33, communication line pair 43, communication line pair 53). Communicate with each other via a pair of communication lines. Specifically, base unit 100 includes terminal pair 145 including terminal 141 and terminal 142, and terminal pair 146 including terminal 143 and terminal 144. The subunit | mobile_unit 200 is provided with the terminal pair 245 containing the terminal 241 and the terminal 242 and the terminal pair 246 containing the terminal 243 and the terminal 244. The subunit | mobile_unit 300 is provided with the terminal pair 345 containing the terminal 341 and the terminal 342, and the terminal pair 346 containing the terminal 343 and the terminal 344. The subunit | mobile_unit 400 is provided with the terminal pair 445 containing the terminal 441 and the terminal 442, and the terminal pair 446 containing the terminal 443 and the terminal 444. The subunit | mobile_unit 500 is provided with the terminal pair 545 containing the terminal 541 and the terminal 542, and the terminal pair 546 containing the terminal 543 and the terminal 544.

  Terminal 141 and terminal 143 are connected inside base unit 100, and terminal 142 and terminal 144 are connected inside base unit 100. Terminal 241 and terminal 243 are connected inside slave unit 200, and terminal 242 and terminal 244 are connected inside slave unit 200. Terminal 341 and terminal 343 are connected inside slave unit 300, and terminal 342 and terminal 344 are connected inside slave unit 300. Terminal 441 and terminal 443 are connected inside slave unit 400, and terminal 442 and terminal 444 are connected inside slave unit 400. Terminal 541 and terminal 543 are connected inside slave unit 500, and terminal 542 and terminal 544 are connected inside slave unit 500.

  In FIG. 1, the slave unit 300 and the slave unit 500 are erroneously connected by the communication line pair 53 including the communication line 51 and the communication line 52, and a plurality of paths connecting the master unit 100 and a specific slave unit are generated. An example in which erroneous wiring (hereinafter simply referred to as “miswiring”) occurs is shown. This miswiring is also called a loop wiring because a loop is formed by a plurality of paths connecting the parent device 100 and a specific child device. If there is this miswiring, the master unit 100 or a plurality of slave units may fail or a communication error may occur. For this reason, in the present embodiment, when an incorrect wiring is detected, the connection relationship is automatically adjusted so that the influence of the incorrect wiring does not occur (the loop wiring is eliminated). Hereinafter, in order to facilitate understanding, a case where there is no erroneous wiring will be described first.

  Master device 100 and slave device 200 are connected to each other by communication line pair 13 including communication line 11 and communication line 12. That is, the terminal 141 and the terminal 241 are connected by the communication line 11, and the terminal 142 and the terminal 242 are connected by the communication line 12. The subunit | mobile_unit 200 and the subunit | mobile_unit 300 are mutually connected by the communication line pair 23 containing the communication line 21 and the communication line 22. FIG. That is, the terminal 243 and the terminal 341 are connected by the communication line 21, and the terminal 244 and the terminal 342 are connected by the communication line 22. Master device 100 and slave device 400 are connected to each other by communication line pair 33 including communication line 31 and communication line 32. That is, the terminal 143 and the terminal 441 are connected by the communication line 31, and the terminal 144 and the terminal 442 are connected by the communication line 32. The slave unit 400 and the slave unit 500 are connected to each other by a communication line pair 43 including a communication line 41 and a communication line 42. That is, the terminal 443 and the terminal 541 are connected by the communication line 41, and the terminal 444 and the terminal 542 are connected by the communication line 42.

  Here, when the wiring length becomes long, the influence of the voltage drop in the wiring becomes large, and there is a high possibility that communication by the voltage signal cannot be normally performed. Therefore, the parent device 100, the child device 200, the child device 300, the child device 400, and the child device 500 are connected so that the wiring length is within a predetermined length (for example, 100 m). In FIG. 1, the length of the communication line pair 13 is 30 m, the length of the communication line pair 23 is 20 m, the length of the communication line pair 33 is 50 m, and the length of the communication line pair 43 is 50 m. An example is shown. In this case, the wiring length from the parent device 100 to the child device 200 is 30 m, the wiring length from the parent device 100 to the child device 300 is 30 m + 20 m = 50 m, and the wiring length from the parent device 100 to the child device 400 is 50 m. The wiring length from the parent device 100 to the child device 500 is 50 m + 50 m = 100 m. Therefore, master device 100 can normally transmit a voltage signal to any of slave device 200, slave device 300, slave device 400, and slave device 500.

  When transmitting data to any of the slave units, base unit 100 applies a predetermined power supply voltage (for example, 12 V or 24 V) between terminal pair 145 while inverting the polarity. The data is basically binary data expressed by a combination of 1 and 0. For example, base unit 100 applies 12V to terminal 141 and terminal 143 and applies 0V to terminal 142 and terminal 144 during a period in which a bit corresponding to 0 is transmitted. On the other hand, base unit 100 applies 0 V to terminal 141 and terminal 143 and 12 V to terminal 142 and terminal 144 during a period in which a bit corresponding to 1 is transmitted.

  Here, when the influence of the voltage drop according to the wiring length is small, basically, the terminal 141, the terminal 143, the terminal 241, the terminal 243, the terminal 341, the terminal 343, the terminal 443, the terminal 543, the terminal 541, and the terminal 543 The same voltage is applied to. Therefore, the plurality of slave units can receive data from the master unit 100 by monitoring the polarity of the power supply voltage applied between the terminal pairs.

  For example, the slave device 200 transmits a bit corresponding to 0 during a period in which the polarity of the voltage between the terminal pair 245 is negative (for example, a period in which 12V is applied to the terminal 241 and 0V is applied to the terminal 242). It can be regarded as a period. On the other hand, the slave unit 200 transmits a bit corresponding to 1 during a period in which the polarity of the voltage between the terminal pair 245 is positive (for example, a period in which 0V is applied to the terminal 241 and 12V is applied to the terminal 242). It can be regarded as a period. And the subunit | mobile_unit 200 can receive the data transmitted by the main | base station 100 combining the received bit. It is assumed that the bit string constituting the data includes a bit string indicating the data transmission source or transmission destination device.

  On the other hand, when transmitting data to the parent device 100, the plurality of child devices transmit data to the parent device 100 by switching between a conductive state and a non-conductive state between the terminal pairs. For example, the slave unit 200 controls the terminal pair 245 to be in a conductive state during a period of transmitting a bit corresponding to 1, and controls the terminal pair 245 to be in a non-conductive state during a period of transmitting a bit corresponding to 0. Here, since a power supply voltage is applied between the terminal pair 245, a current flows through the communication line pair 13 when the terminal pair 245 is controlled to be conductive. A current flowing through the communication line pair 13 means that a current flows through the communication line 11 and the communication line 12. Basically, the magnitude of the current flowing through the communication line 11 and the magnitude of the current flowing through the communication line 12 are approximately the same, and the direction of the current flowing through the communication line 11 is opposite to the direction of the current flowing through the communication line 12. The direction. Hereinafter, “the magnitude of current” is simply referred to as “current” as appropriate.

  On the other hand, master device 100 can receive data from slave device 200 by detecting the presence or absence of current flowing through communication line pair 13. For example, base unit 100 can be regarded as a period in which a bit corresponding to 1 is transmitted during a period in which a current equal to or greater than a threshold value flows in communication line pair 13. On the other hand, base unit 100 can be regarded as a period in which a current greater than or equal to the threshold value does not flow through communication line pair 13 and a period in which a bit corresponding to 0 is transmitted. And the main | base station 100 can receive the data transmitted by the subunit | mobile_unit 200 combining the received bit.

  Here, when there is no miswiring, that is, when handset 300 and handset 500 are not connected by communication line pair 53, handset 300 is connected only to handset 200. Therefore, while the slave unit 200 transmits data, the path through which current flows from the slave unit 200 to the master unit 100 is only the communication line pair 13.

  Next, a case where there is an incorrect wiring, that is, a case where the slave unit 300 and the slave unit 500 are connected by the communication line pair 53 including the communication line 51 and the communication line 52 will be described. In this case, the terminal 343 and the terminal 543 are connected by the communication line 51, and the terminal 344 and the terminal 544 are connected by the communication line 52. Note that the length of the communication line pair 53 is 20 m.

  Here, for example, a case where the slave device 200 transmits data to the master device 100 is assumed. In this case, the slave unit 200 controls the terminal pair 245 to be in a conductive state during a period in which a bit corresponding to 1 is transmitted. When the terminal pair 245 is controlled to be in a conductive state, a power supply voltage is applied between the terminal pair 245, so that a current flows through the communication line pair 13. However, between the slave unit 200 and the master unit 100, the path 1 configured by the communication line pair 13, the communication line pair 23, the communication line pair 53, the communication line pair 43, and the communication line pair 33 are configured. There are two current paths with path 2. Accordingly, when the terminal pair 245 is controlled to be conductive, a current also flows through the communication line pair 23, the communication line pair 53, the communication line pair 43, and the communication line pair 33.

  The length of the route 1 is 30 m, and the length of the route 2 is 20 m + 20 m + 50 m + 50 m = 140 m. Therefore, the magnitude of the current flowing through the path 1 is larger than the magnitude of the current flowing through the path 2. The magnitude of the current monitored by base unit 100 is the sum of the magnitude of the current flowing through path 1 and the magnitude of the current flowing through path 2. Therefore, the magnitude of the current monitored by the master unit 100 is larger when there is an incorrect wiring than when there is no erroneous wiring. It can be considered that there is no problem in itself that the magnitude of the current monitored by the master unit 100 becomes large. However, the presence of miswiring itself means that an unexpected connection has been made, and there is a possibility of failure of the master unit 100 or a plurality of slave units, or communication failure. Therefore, when transmitting data, the plurality of slave units checks whether or not there is a miswiring, and if miswiring is detected, automatically adjusts the connection relationship so that the influence of the miswiring is eliminated.

  For example, the slave unit 200 controls the terminal pair 245 to be in a conductive state during a period in which a bit corresponding to 1 is transmitted, and confirms whether or not a current flows through both the path 1 and the path 2. Then, when detecting that the current flows through both the path 1 and the path 2, the slave unit 200 blocks the path (for example, the path 2) with the smaller flowing current. Note that a small amount of current flowing through the path means that the length of the path is long. In general, the normal path is designed to be short. For this reason, a long route is more likely to be a route formed by miswiring than a short route. In addition, when a short route is blocked and a long route is left, there is a possibility that normal communication cannot be performed. Therefore, when an incorrect wiring is detected, it is preferable that the path with the smaller flowing current is blocked.

  Next, with reference to FIG. 2, the structure of the main | base station 100 and the subunit | mobile_unit 200 is demonstrated. In addition, the structure of the subunit | mobile_unit 300, the subunit | mobile_unit 400, and the subunit | mobile_unit 500 is the same as that of the subunit | mobile_unit 200 fundamentally.

  Base unit 100 includes transmission circuit 110, reception circuit 120, control unit 130, terminal pair 145, terminal pair 146, notification unit 150, power supply terminal 161, capacitor 162, and ground terminal 163. Prepare.

  The transmission circuit 110 transmits data using a voltage signal in accordance with control by the control unit 130. The transmission circuit 110 outputs an H-level voltage (for example, 5 V) from a first transmission terminal (terminal indicated by Tx1) (not shown) provided in the control unit 130, and a second transmission terminal (not shown) provided in the control unit 130. When an L-level voltage (for example, 0 V) is output from (a terminal indicated by Tx2), 0 V is applied to the terminal 141 and V1 is applied to the terminal 142. On the other hand, the transmission circuit 110 applies V1 to the terminal 141 and 0V to the terminal 142 when an L level voltage is output from the first transmission terminal and an H level voltage is output from the second transmission terminal. Apply. V1 is a power supply voltage of base unit 100.

  Note that the voltage level output from the second transmission terminal is opposite to the voltage level output from the first transmission terminal. For example, when transmitting a bit corresponding to 1, the control unit 130 outputs an H level voltage from the first transmission terminal, and outputs an L level voltage from the second transmission terminal. Further, when transmitting a bit corresponding to 0, the control unit 130 outputs an L level voltage from the first transmission terminal, and outputs an H level voltage from the second transmission terminal. Therefore, when a bit corresponding to 1 is transmitted, the voltage of the terminal 141 is lower than the voltage of the terminal 142, and when a bit corresponding to 0 is transmitted, the voltage of the terminal 141 is higher than the voltage of the terminal 142. Become. Basically, the voltage at the terminal 141 and the voltage at the terminal 143 are the same, and the voltage at the terminal 142 and the voltage at the terminal 144 are the same.

  The transmission circuit 110 includes an NPN (Negative Positive Negative) transistor 111, a PNP (Positive Negative Positive) transistor 112, an NPN transistor 113, and a PNP transistor 114. The collector of the NPN transistor 111 and the collector of the NPN transistor 113 are connected to the power supply terminal 161. The base of the NPN transistor 111 and the base of the PNP transistor 112 are connected to the first transmission terminal. The emitter of NPN transistor 111 and the emitter of PNP transistor 112 are connected to terminal 142 and terminal 144.

  The collector of the PNP transistor 112 and the collector of the PNP transistor 114 are connected to the ground terminal 128 through the resistor 126 and are connected to the non-inverting input terminal of the operational amplifier 122 through the capacitor 123. The base of the NPN transistor 113 and the base of the PNP transistor 114 are connected to the second transmission terminal. The emitter of the NPN transistor 113 and the emitter of the PNP transistor 114 are connected to the terminal 141 and the terminal 143. When the NPN transistor 111 and the PNP transistor 114 are turned on, the NPN transistor 113 and the PNP transistor 114 are turned off. Further, when the NPN transistor 111 and the PNP transistor 114 are turned off, the NPN transistor 113 and the PNP transistor 114 are turned on.

  The receiving circuit 120 supplies a voltage signal corresponding to data (bit data) transmitted as a current signal from any of the slave units to the control unit 130. When the reception circuit 120 detects that the current flowing through the communication line pair 13 or the communication line pair 33 is equal to or greater than a predetermined threshold, the reception circuit 120 is connected to a reception terminal (terminal indicated by Rx) included in the control unit 130. An H level voltage signal is supplied. On the other hand, when the reception circuit 120 detects that the current flowing through the communication line pair 13 or the communication line pair 33 is less than the threshold value, the reception circuit 120 supplies an L level voltage signal to the reception terminal.

  The receiving circuit 120 includes a power supply terminal 121, an operational amplifier 122, a capacitor 123, a resistor 124, a resistor 125, a resistor 126, a ground terminal 127, and a ground terminal 128. The power supply terminal 121 is connected to a DC power supply (not shown) provided in the parent device 100, and a power supply voltage (V1) is applied. The operational amplifier 122 compares the input voltage applied to the non-inverting input terminal with the reference voltage applied to the inverting input terminal. The operational amplifier 122 outputs an H level voltage from the output terminal when the input voltage is higher than the reference voltage, and outputs an L level voltage from the output terminal when the input voltage is lower than the reference voltage.

  The capacitor 123 blocks a DC component supplied to the inverting input terminal of the operational amplifier 122. The resistor 124 and the resistor 125 are connected in series between the power supply terminal 121 and the ground terminal 127. The resistor 124 and the resistor 125 apply a reference voltage obtained by dividing the power supply voltage to the inverting input terminal of the operational amplifier 122. The resistor 126 limits the current flowing from the power supply terminal 161 to the ground terminal 128. The ground terminal 127 and the ground terminal 128 are connected to a DC power source (not shown) included in the parent device 100, and 0 V is applied.

  Control unit 130 controls the overall operation of base unit 100. The control unit 130 controls the transmission circuit 110 to transmit data to one of the slave units. For example, the control unit 130 outputs a voltage at a level corresponding to the bit data to be transmitted from the first transmission terminal. Note that the control unit 130 outputs a voltage having a level opposite to that of the voltage output from the first transmission terminal, from the second transmission terminal. Further, the control unit 130 specifies data transmitted from any of the slave units based on the voltage signal supplied from the receiving circuit 120. For example, the control unit 130 samples bit data corresponding to the level of the voltage applied to the reception terminal, and specifies transmitted data from the bit data string obtained by the sampling.

  In addition, when an incorrect wiring is detected, the control unit 130 controls the notification unit 150 to notify that an incorrect wiring has been detected. The control unit 130 is configured by a microcomputer including, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.

  The terminal pair 145 includes a terminal 141 and a terminal 142. The terminal pair 145 is connected to the terminal pair 245 through the communication line pair 13. That is, the terminal 141 is connected to the terminal 241 via the communication line 11, and the terminal 142 is connected to the terminal 242 via the communication line 12. The terminal pair 146 includes a terminal 143 and a terminal 144. The terminal pair 146 is connected to the terminal pair 445 through the communication line pair 33. That is, the terminal 143 is connected to the terminal 441 via the communication line 31, and the terminal 144 is connected to the terminal 442 via the communication line 32.

  The notification unit 150 notifies the user by light, an image, and a sound that erroneous wiring has been detected according to control by the control unit 130. The notification unit 150 is, for example, an LED (Light Emitting Diode), a liquid crystal display, a touch screen, or a speaker.

  The power supply terminal 161 is connected to a DC power supply provided in the parent device 100, and a power supply voltage is applied thereto. The capacitor 162 is provided between the power supply terminal 161 and the ground terminal 163, and allows an AC component (high frequency component) output from the power supply terminal 161 to flow to the ground terminal 163. The ground terminal 163 is connected to a DC power source included in the parent device 100 and 0 V is applied.

  The slave device 200 includes a transmission circuit 110, a reception circuit 120, a control unit 230, a terminal pair 245, a terminal pair 246, a rectifier circuit 250, a switch 261, a switch 262, a current detection unit 263, a current A detection unit 264, a connection point 265, a connection point 266, a comparison unit 270, a signal output unit 280, and a power supply terminal 291 are provided.

  Transmission circuit 210 transmits data to base unit 100 by a current signal according to control by control unit 230. The transmission circuit 210 includes an NPN transistor 211 and a resistor 212. The collector of the NPN transistor 211 is connected to the power supply terminal 291. The base of the NPN transistor 211 is connected to a transmission terminal (terminal indicated by Tx) (not shown) included in the control unit 230. The emitter of the NPN transistor 211 is connected through a resistor 212 to a reference terminal (terminal indicated by S0) (not shown) included in the control unit 230. The NPN transistor 211 is turned on when an H level voltage is applied to the base, and turned off when an L level voltage is applied to the base. When the NPN transistor 211 is turned off, no current flows through the communication line pair 13. On the other hand, when the NPN transistor 211 is turned on, a current flows through the communication line pair 13.

  When the NPN transistor 211 is turned on when the voltage at the terminal 241 is higher than the voltage at the terminal 242, the power supply terminal 161 → the NPN transistor 113 → the terminal 141 → the communication line 11 → the terminal 241 → the switch 261 → the diode 253 → the power supply terminal 291. → NPN transistor 211 → resistor 212 → diode 252 → switch 261 → terminal 242 → communication line 12 → terminal 142 → PNP transistor 112 → resistor 126 → grounding terminal 128, current flows. On the other hand, when the NPN transistor 211 is turned on when the voltage at the terminal 241 is lower than the voltage at the terminal 242, the power supply terminal 161 → the NPN transistor 111 → the terminal 142 → the communication line 12 → the terminal 242 → the switch 261 → the diode 254 → the power supply. Current flows through a path of terminal 291 → NPN transistor 211 → resistor 212 → diode 251 → switch 261 → terminal 241 → communication line 11 → terminal 141 → PNP transistor 114 → resistor 126 → ground terminal 128. The resistor 212 is a load resistor and limits the current flowing in the current path of the NPN transistor 211.

  The receiving circuit 220 supplies a voltage signal corresponding to data (bit data) transmitted as a voltage signal from the parent device 100 to the control unit 230. When the voltage at the terminal 242 is higher than the voltage at the terminal 241, the receiving circuit 220 supplies a voltage signal of H level (for example, 5 V) to a not-shown receiving terminal (terminal indicated by Rx) included in the control unit 230. . On the other hand, when the voltage at the terminal 241 is higher than the voltage at the terminal 242, the receiving circuit 220 supplies an L level (for example, 0 V) voltage signal to the receiving terminal included in the control unit 230.

  The receiving circuit 220 includes a Zener diode 221, a resistor 222, and a resistor 223. The anode of the Zener diode 221 is connected to the reference terminal, and the cathode of the Zener diode 221 is connected to the receiving terminal. The Zener diode 221 prevents the voltage at the reception terminal from becoming higher than the breakdown voltage (for example, 5 V) with respect to the voltage at the reference terminal. The resistor 222 is provided between the connection point 266 and the reception terminal, and limits the voltage applied to the reception terminal. The resistor 223 is provided between the reference terminal and the receiving terminal in parallel with the Zener diode 221.

  The control unit 230 controls the overall operation of the child device 200. Control unit 230 controls transmission circuit 210 to transmit data to base unit 100. For example, the control unit 230 outputs a voltage at a level corresponding to the bit data to be transmitted from the transmission terminal. Further, the control unit 230 specifies data transmitted from the parent device 100 based on the voltage signal supplied from the receiving circuit 220. For example, the control unit 230 samples bit data corresponding to the level of the voltage applied to the reception terminal, and specifies transmitted data from the bit data string obtained by the sampling. In addition, the control unit 230 performs illumination control (not shown) according to the control by the parent device 100. The control unit 230 is configured by a microcomputer including a CPU, a ROM, a RAM, and the like, for example.

  The terminal pair 245 includes a terminal 241 and a terminal 242. The terminal pair 246 includes a terminal 243 and a terminal 244. The terminal pair 246 is connected to the terminal pair 345 through the communication line pair 23. That is, the terminal 243 is connected to the terminal 341 via the communication line 21, and the terminal 244 is connected to the terminal 342 via the communication line 22.

  The rectifier circuit 250 rectifies positive and negative power supply voltages applied between the terminal pair 245, and generates V2 that is an operation power supply of the slave unit 200. Note that V2 that is the operation power supply of the slave unit 200 is approximately the same voltage as the power supply voltage V1 of the master unit 100, and is supplied from the power supply terminal 291 to each module. The rectifier circuit 250 includes a diode 251, a diode 252, a diode 253, and a diode 254. The anode of the diode 251 and the anode of the diode 252 are connected to one output terminal (low voltage side output terminal). The cathode of the diode 253 and the cathode of the diode 254 are connected to the other output terminal (high voltage side output terminal). The cathode of the diode 251 and the anode of the diode 253 are connected to a connection point 265 that is one input terminal. The cathode of the diode 252 and the anode of the diode 254 are connected to a connection point 266 that is the other input terminal.

  The switch 261 is a switch for disconnecting the communication line pair 13 connected to the terminal pair 245 from the child device 200 according to control by the control unit 230. The switch 261 controls a short circuit / open state between the terminal 241 and the connection point 265 and controls a short circuit / open state between the terminal 242 and the connection point 266. The switch 261 controls the short circuit / open state between the terminal 241 and the connection point 265 and the short circuit / open state between the terminal 242 and the connection point 266 to the same short circuit / open state. The switch 261 is, for example, a double switch that controls between two pairs of contacts simultaneously.

  The switch 262 is a switch for disconnecting the communication line pair 23 connected to the terminal pair 246 from the slave unit 200 according to control by the control unit 230. The switch 262 controls the short circuit / open state between the terminal 243 and the connection point 265 and also controls the short circuit / open state between the terminal 244 and the connection point 266. The switch 262 controls the short circuit / open state between the terminal 243 and the connection point 265 and the short circuit / open state between the terminal 244 and the connection point 266 to the same short circuit / open state. The switch 262 is, for example, a double switch that simultaneously controls between two pairs of contacts.

  The current detection unit 263 detects a current flowing through the communication line pair 13 and supplies a voltage signal indicating the magnitude of the detected current to the comparison unit 270. In the present embodiment, the current detection unit 263 detects the current flowing through the communication line 11 by detecting the current flowing between the terminal 241 and the connection point 265. However, the current detection unit 263 may detect the current flowing through the communication line 12 by detecting the current flowing between the terminal 242 and the connection point 266. The current detection unit 263 includes, for example, a current detection shunt resistor or a current transformer.

  The current detection unit 264 detects a current flowing through the communication line pair 23 and supplies a voltage signal indicating the magnitude of the detected current to the comparison unit 270. In the present embodiment, the current detection unit 264 detects the current flowing through the communication line 21 by detecting the current flowing between the terminal 243 and the connection point 265. However, the current detection unit 264 may detect the current flowing through the communication line 22 by detecting the current flowing between the terminal 244 and the connection point 266. The current detection unit 264 includes, for example, a current detection shunt resistor or a current transformer.

  The connection point 265 is a point on the wiring connecting the switch 261 and the switch 262 when the terminal 241 and the terminal 243 are connected via the switch 261 and the switch 262. The connection point 265 is connected to one input terminal included in the rectifier circuit 250. The connection point 266 is a point on the wiring connecting the switch 261 and the switch 262 when the terminal 242 and the terminal 244 are connected via the switch 261 and the switch 262. The connection point 266 is connected to the other input terminal included in the rectifier circuit 250.

  The transmission circuit 210 controls the current flowing through the communication line pair 13 by controlling the conduction / non-conduction state between the connection point 265 and the connection point 266. That is, the transmission circuit 210 controls the connection between the connection point 265 and the connection point 266 when current flows through the communication line pair 13 and connects with the connection point 265 when current does not flow through the communication line pair 13. Control is made between the point 266 and the non-conductive state.

  The comparison unit 270 compares the magnitude of the current indicated by the voltage signal supplied from the current detection unit 263 with a predetermined threshold value, and whether the current passed by the transmission circuit 210 is flowing through the communication line pair 13. Determine whether or not. Further, the comparison unit 270 compares the magnitude of the current indicated by the voltage signal supplied from the current detection unit 264 with a predetermined threshold, and the current passed by the transmission circuit 210 flows to the communication line pair 23. It is determined whether or not. The comparison unit 270 supplies a voltage signal indicating the determination result to the signal output unit 280.

  The comparison unit 270 compares the magnitude of the current indicated by the voltage signal supplied from the current detection unit 263 with the magnitude of the current indicated by the voltage signal supplied from the current detection unit 264, and It is determined which of the communication line pair 23 is receiving a large current. The comparison unit 270 supplies a voltage signal indicating the determination result to the signal output unit 280. The comparison unit 270 includes, for example, a comparator, an A / D (Analog / Digital) converter, a microcomputer, and the like.

  The signal output unit 280 determines whether there is a miswiring based on the voltage signal supplied from the comparison unit 270. When the signal output unit 280 determines that there is an incorrect wiring, the signal output unit 280 supplies a signal (hereinafter referred to as an “incorrect wiring detection signal”) indicating that the erroneous wiring has been detected to the control unit 230. The miswiring detection signal may include information indicating which of the communication line pair 13 and the communication line pair 23 has a larger current. Further, the signal output unit 280 can determine whether or not the transmission circuit 210 is passing current based on the voltage signal supplied from the control unit 230. The signal output unit 280 is configured by, for example, a microcomputer including a CPU, a ROM, a RAM, and the like.

  The power supply terminal 291 is a power supply terminal for supplying each module with V2 that is the operation power supply of the slave unit 200 generated by the rectifier circuit 250. Note that description of the slave unit 300 in FIG. 2 is omitted.

  Next, a communication control process executed by the child device 200 will be described with reference to the flowchart shown in FIG. The slave device 200 is connected to the master device 100, for example, and starts communication control processing when the power is turned on. Here, it is assumed that the switch 261 and the switch 262 included in the slave device 200 are in a conductive state when the power is turned on. Note that the communication control process executed by the slave units 300, 400, and 500 is basically the same as the communication control process executed by the slave unit 200, and therefore the description is omitted or simplified. In the present embodiment, basically, base unit 100 does not execute processing related to detection of erroneous wiring, and therefore, description of processing of base unit 100 is omitted or simplified.

  First, the control unit 230 monitors the level of the receiving terminal (step S101). That is, the control unit 230 samples the level of the voltage applied from the receiving circuit 220 to the receiving terminal. When the process of step S101 is completed, control unit 230 determines whether or not data has been received from parent device 100 (step S102). For example, the control unit 230 generates a bit string based on the sampled voltage level and determines whether one frame of data has been received. If control unit 230 determines that data has not been received from base unit 100 (step S102: NO), it returns the process to step S101.

  On the other hand, when determining that data has been received from parent device 100 (step S102: YES), control unit 230 executes processing according to the received data (step S103). For example, when the control unit 230 receives data instructing to turn on the lighting, the control unit 230 turns on the lighting. When the process of step S103 is completed, the control unit 230 generates a bit string of data to be transmitted (step S104). Note that the data to be transmitted is data returned to the parent device 100.

  When the process of step S104 is completed, the control unit 230 selects a bit to be transmitted from the generated bit string (step S105). Note that bits are selected in order from the top of the generated bit string. When the process of step S105 is completed, the control unit 230 sets the transmission terminal to a level corresponding to the selected bit (step S106). For example, when the selected bit is 1, the transmission terminal is set to H level (for example, 5V), and when the selected bit is 0, the transmission terminal is set to L level (for example, 0V). .

  When the process of step S106 is completed, the controller 230 determines whether or not the level of the transmission terminal is the H level (step S107). Note that the level of the transmission terminal being H level means that the transmission circuit 210 controls the connection point 265 and the connection point 266 to be in a conductive state, and a current flows. When determining that the level of the transmission terminal is the H level (step S107: YES), the controller 230 executes an erroneous wiring detection process (step S108). The erroneous wiring detection process will be described in detail with reference to the flowchart shown in FIG.

  First, the current detection unit 263 detects the first current (step S201). The first current is, for example, a current that flows through the communication line 11. Next, the current detection unit 264 detects the second current (step S202). The second current is, for example, a current that flows through the communication line 21. Here, the comparison unit 270 determines whether or not the first current and the second current are greater than or equal to a threshold value (step S203). When the comparison unit 270 determines that the first current or the second current is not greater than or equal to the threshold (step S203: NO), the control unit 230 ends the erroneous wiring detection process.

  When the comparison unit 270 determines that the first current and the second current are greater than or equal to the threshold (step S203: YES), the signal output unit 280 outputs an erroneous wiring detection signal to the control unit 230 (step S204). . The erroneous wiring detection signal includes the magnitude of the first current, the magnitude of the second current, whether or not the first current and the second current are equal to or greater than a threshold value, and the first current and the second current. Information indicating the magnitude relationship with the current 2 may be included. When the signal output unit 280 completes the process of step S204, the control unit 230 determines whether or not the first current is equal to or less than the second current (step S205).

  When determining that the first current is equal to or less than the second current (step S205: YES), the control unit 230 controls the first switch to be in an open state (step S206). Note that the first switch is the switch 261. On the other hand, when determining that the first current is not less than or equal to the second current (step S205: NO), the control unit 230 controls the second switch to be in an open state (step S207). Note that the second switch is the switch 262.

  For example, as shown in FIG. 1, it is assumed that the terminal pair 346 and the terminal pair 546 are connected by the communication line pair 53 and erroneous wiring occurs. In this case, in step S203, it is determined that the first current and the second current are greater than or equal to the threshold value. Here, the length of the path through which the first current flows is 30 m, which is the length of the communication line pair 13. On the other hand, the length of the path through which the second current flows is 20 m of the communication line pair 23, 20 m of the communication line pair 53, 50 m of the communication line pair 43, and the communication line pair. The total length of 33 and 50 m is 140 m. Accordingly, in step S205, it is determined that the first current is not less than or equal to the second current, and in step S207, the switch 262 that is the second switch is controlled to be in the open state. For this reason, the communication line pair 23 is disconnected from the slave unit 200, and the loop wiring is eliminated. When completing the process of step S206 or step S207, the controller 230 ends the erroneous wiring detection process.

  When the process of step S108 is completed, the controller 230 waits for one bit (step S109). When the process of step S109 is completed, the control unit 230 determines whether all bits have been selected (step S110). When determining that all the bits have been selected (step S110: YES), the control unit 230 considers that the data transmission has been completed, and returns the process to step S101. On the other hand, when determining that any bit has not been selected (step S110: NO), the control unit 230 returns the process to step S105 and selects the next bit.

  In the present embodiment, the first current flowing through the communication line pair 13 and the second current flowing through the communication line pair 23 when the connection point 265 and the connection point 266 are controlled to be conductive. If the magnitude of the is greater than or equal to a predetermined threshold, an erroneous wiring detection signal is output. Therefore, according to the present invention, it is possible to detect an erroneous wiring that causes a plurality of paths connecting the parent device 100 and the child device 200.

  In the present embodiment, when an erroneous wiring detection signal is output, one of the first switch and the second switch is controlled to be open. Therefore, according to this embodiment, it is possible to have one route connecting the parent device 100 and the child device 200. In the present embodiment, when an erroneous wiring detection signal is output, the shorter path is not disconnected from the slave unit 200, and the longer path is disconnected from the slave unit 200. Therefore, according to the present embodiment, it can be expected that the possibility of communication abnormality occurring due to the disconnection of the route is reduced.

(Embodiment 2)
In the first embodiment, an example has been described in which, when erroneous wiring that causes a plurality of routes connecting the parent device 100 and the child device 200 is detected, the longer route is disconnected by the child device 200 and the process is completed. However, this method may not be preferable when a plurality of paths connecting the parent device 100 and the child device 200 are generated due to an incorrect wiring with respect to another child device instead of an incorrect wiring with respect to the child device 200.

  For example, in the first embodiment, the communication line pair 23 is disconnected from the child device 200 due to erroneous wiring of the communication line pair 53, but it is preferable that the communication line pair 53 is disconnected from the child device 300 or the child device 500. Actually, when the communication line pair 23 is disconnected from the child device 200, the length of the path from the child device 300 to the parent device 100 is 20 m, which is the length of the communication line pair 53, and 50 m, which is the length of the communication line pair 43. Then, the length of the communication line pair 33 is 50 m, which is a total of 120 m, and there is a possibility that the slave device 300 and the master device 100 cannot communicate with each other.

  Therefore, in the present embodiment, when a faulty wiring is detected by the slave unit 200, the slave unit 200 notifies the master unit 100 that the faulty wiring has been detected, and an appropriate communication line pair is controlled according to the control by the master unit 100. A method for cutting off will be described. Note that the configuration of the communication system 1000 according to the present embodiment is basically the same as the configuration of the communication system 1000 according to the first embodiment. Therefore, in the present embodiment, description of the configuration of the communication system 1000 is omitted, and mainly the processing of the communication system 1000 will be described.

  First, with reference to the flowchart of FIG. 5, the miswiring detection process which the subunit | mobile_unit 200 performs is demonstrated. The erroneous wiring detection process shown in FIG. 5 is a process executed in place of the erroneous wiring detection process shown in FIG. In addition, since the communication control process which the subunit | mobile_unit 200 which concerns on this embodiment performs is the same as that of the communication control process shown in FIG. 3, description is abbreviate | omitted.

  First, the control unit 230 determines whether or not a start bit is being transmitted (step S301). When determining that the start bit is not being transmitted (step S301: NO), the controller 230 ends the miswiring detection process. As described above, in this embodiment, the slave unit 200 does not transmit the start bit even when the level of the transmission terminal is H level (when the bit corresponding to 1 is being transmitted). The miswiring detection process is not executed.

  When determining that the start bit is being transmitted (step S301: YES), the control unit 230 determines whether or not the erroneous wiring detection process is being exempted (step S302). When determining that the erroneous wiring detection process is exempted (step S302: YES), the controller 230 ends the erroneous wiring detection process. As described above, in this embodiment, the slave unit 200 does not execute the miswiring detection process when the miswiring detection process is exempted even when the start bit is being transmitted. For example, after the cordless handset 200 detects one of the switches that has been miswired and is controlled to be in the open state, after returning the switch to the short-circuited state according to an instruction from the base unit 100, the control cancellation indicating that the one switch is returned to the short-circuited state The miswiring detection process is exempted until data indicating completion is transmitted to the master unit.

  When the controller 230 determines that the erroneous wiring detection process is not exempted (step S302: NO), the current detector 263 detects the first current (step S303), and the current detector 264 detects the second current. A current is detected (step S304). Then, the comparison unit 270 determines whether or not the first current and the second current are greater than or equal to a threshold value (step S305). When the comparison unit 270 determines that the first current or the second current is not greater than or equal to the threshold (step S305: NO), the control unit 230 ends the erroneous wiring detection process.

  When the comparison unit 270 determines that the first current and the second current are greater than or equal to the threshold (step S305: YES), the signal output unit 280 outputs an erroneous wiring detection signal to the control unit 230 (step S306). . When the signal output unit 280 completes the process of step S306, the control unit 230 determines whether or not the first current is equal to or less than the second current (step S307).

  When determining that the first current is equal to or less than the second current (step S307: YES), the control unit 230 controls the first switch to be in an open state (step S308). On the other hand, when determining that the first current is not less than or equal to the second current (step S307: NO), the control unit 230 controls the second switch to be in an open state (step S309).

  When the processing of step S308 or step S309 is completed, control unit 230 transmits data indicating the completion of control to parent device 100 (step S310). The data indicating the completion of control is data for notifying the master unit 100 that the slave unit 200 has opened one of the switches in response to detection of erroneous wiring. Since slave unit 100 executes miswiring detection processing during transmission of a start bit, data indicating control completion is promptly rewritten by replacing the bit string after the start bit with a bit string constituting data indicating control completion. Can be sent. When the process of step S310 is completed, the controller 230 ends the erroneous wiring detection process.

  Next, communication control processing executed by the parent device 100 will be described with reference to the flowchart shown in FIG. This communication control process is a process for causing an appropriate pair of communication lines to be disconnected by an appropriate slave unit when an erroneous wiring is detected by any one of the plurality of slave units. When power is turned on, base unit 100 starts executing the communication control process shown in FIG.

  First, the control unit 130 monitors the level of the receiving terminal (step S401). That is, the control unit 130 samples the level of the voltage applied from the receiving circuit 120 to the receiving terminal. When the processing of step S401 is completed, control unit 130 determines whether data indicating control completion has been received from the first slave unit (step S402). For example, the control unit 130 generates a bit string based on the sampled voltage level, generates data for one frame, and whether the generated data for one frame is data indicating completion of control. Is determined. The first slave unit is a slave unit that has transmitted data indicating control completion, and is a slave unit that has detected an incorrect wiring. In the present embodiment, it is assumed that the first slave unit is the slave unit 200. If it is determined that data indicating control completion has not been received from the first slave unit (step S402: NO), control unit 130 returns the process to step S401.

  On the other hand, when determining that the data indicating the completion of control is received from the first slave unit (step S402: YES), control unit 130 transmits data requesting a response to all the slave units (step S403). The data requesting the response is sent to the slave unit that is interested in transmitting the data indicating the response to the master unit 100 in order to determine whether the master unit 100 and the slave unit that is focused can communicate with each other. The requested data. The data indicating the response is data returned from the slave unit that has received the data requesting the response from the master unit 100 to the master unit 100.

  In the present embodiment, when data is transmitted from the parent device 100 to the target child device, a polling method is employed in which the target child device transmits some data to the parent device 100. Accordingly, the content of data requesting a response may be anything, and the content of data indicating a response may be anything. The control unit 130 sequentially transmits data requesting a response to each of the child device 200, the child device 300, the child device 400, and the child device 500. Note that the control unit 130 may not transmit data requesting a response to the first slave unit. Further, the control unit 130 can transmit data requesting a response by controlling the transmission circuit 110.

  On the other hand, the slave unit that has received the data requesting the response from the base unit 100 determines the bit string that constitutes the data indicating the response in step S104, and the data indicating the response is the base unit in the processing from step S105 to step S110. To 100.

  When the process of step S403 is completed, the control unit 130 determines whether or not data indicating responses has been received from all the slave units (step S404). The reception of data indicating responses from all the slave units means that the master unit 100 and all the slave units can normally communicate in the wiring state after the switch control by the first slave unit. . On the other hand, the fact that no data indicating a response is received from any of the slave units means that the master unit 100 and any of the slave units cannot communicate normally in the wiring state after the switch control by the first slave unit.

  If it is determined that data indicating responses from all the slave units has been received (step S404: YES), control unit 130 returns the process to step S401. On the other hand, when determining that data indicating a response is not received from any of the slave units (step S404: NO), control unit 130 transmits data requesting control release to the first slave unit (step S405).

  On the other hand, the first slave unit that has received the data requesting the control release from the master unit 100 controls one of the switches that have been controlled to the open state to a short-circuit state in step S103. Then, in step S104, the first slave unit determines a bit string that constitutes data indicating completion of control release, and transmits data indicating a response to master unit 100 in the processing from step S105 to step S110. In this case, in step S302, the first slave unit determines that erroneous wiring detection is being exempted, and does not execute the erroneous wiring detection process.

  When the processing of step S405 is completed, control unit 130 receives data indicating completion of control release from the first slave unit (step S406). When the processing of step S406 is completed, control unit 130 transmits data requesting a response to the second slave unit (step S407). The second slave unit is a slave unit for which data indicating a response has not been received in the determination process of step S404. The data requesting the response transmitted in step S407 and the data requesting the response transmitted in step S403 may be the same data or different data. When the control section 130 completes the process step of step S407, the control section 130 returns the process to step S401.

  On the other hand, the second slave unit that has received the data requesting the response from base unit 100 determines the bit string that constitutes the data indicating the response in step S104, and the data indicating the response in the processing from step S105 to step S110. Is transmitted to base unit 100. The second slave unit detects an incorrect wiring in an erroneous wiring detection process executed when data indicating a response is transmitted to the master unit 100. Then, in step S308 or step S309, the second slave unit controls one of the switches to the open state, and in step S310, transmits data indicating control completion to master unit 100.

  Then, when receiving data indicating control completion from the second slave unit, master unit 100 regards the second slave unit as the first slave unit and executes the communication control process shown in FIG. Thereafter, the communication control process shown in FIG. 3, the miswiring detection process shown in FIG. 5, and the communication control process shown in FIG. 6 are performed until it is determined in step S <b> 404 that data indicating responses has been received from all the slave units. Repeatedly executed.

  For example, in the communication system 1000 shown in FIG. 1, it is assumed that an error wiring is first detected by the slave unit 200. In this case, the path from the terminal pair 246 to the terminal pair 345 is longer than the path from the terminal pair 245 to the terminal pair 145. Therefore, the switch 262 connected to the terminal pair 246 is controlled to the open state. Then, the route from the slave device 300 to the master device 100 is only the route from the terminal pair 346 to the terminal pair 146, but the length of this route is 20m + 50m + 50m = 120m, which exceeds 100m. For this reason, the slave unit 300 cannot communicate with the master unit 100. Then, base unit 100 transmits data requesting control release to slave unit 200, causes slave unit 200 to control switch 262 to a short-circuit state, and transmits data requesting response to slave unit 300.

  On the other hand, the slave unit 300 performs an erroneous wiring detection process in the process of transmitting data indicating a response to the master unit 100 in response to receiving the data requesting the response. In this case, the path from the terminal pair 346 to the terminal pair 146 is longer than the path from the terminal pair 345 to the terminal pair 145. Therefore, the switch connected to the terminal pair 346 is controlled to the open state. In this case, the length of the route from the parent device 100 to any child device is also 100 m or less. Therefore, the state in which the slave unit 300 disconnects the communication line pair 53 is maintained, and the master unit 100 can communicate with all the slave units.

  In this embodiment, when an incorrect wiring is detected by any of the slave units, a communication line pair that is likely to cause the incorrect wiring is disconnected. Therefore, according to the present embodiment, it can be expected to automatically and appropriately eliminate the influence of erroneous wiring.

(Embodiment 3)
In the first embodiment and the second embodiment, the example in which the terminal pair provided in the parent device 100 and the plurality of child devices is two has been described. In the present invention, the number of terminal pairs provided in the parent device 100 or the plurality of child devices is not limited to this example as long as there is a possibility that a plurality of paths connecting the parent device 100 and any one of the child devices 200 may occur. . For example, the number of terminal pairs provided in the parent device 100 or the plurality of child devices may be one or three or more. Hereinafter, an example in which the parent device 100 includes one terminal pair, the child device 200 includes three terminal pairs, and the child device 300, the child device 400, and the child device 500 include two terminal pairs will be described.

  With reference to FIG. 7, the structure of the communication system 1100 which concerns on this embodiment is demonstrated. The communication system 1100 includes a parent device 101, a child device 201, a child device 300, a child device 400, and a child device 500. The terminal pair 145 included in the parent device 101 is connected to the terminal pair 245 included in the child device 201 by the communication line pair 13. The terminal pair 246 included in the child device 201 is connected to the terminal pair 345 included in the child device 300 through the communication line pair 23. The terminal pair 249 provided in the child device 201 is connected to the terminal pair 445 provided in the child device 400 by the communication line pair 33. The terminal pair 446 provided in the child device 400 is connected to the terminal pair 545 provided in the child device 500 by the communication line pair 43. Here, it is assumed that the terminal pair 346 included in the child device 300 is erroneously connected to the terminal pair 546 included in the child device 500 by the communication line pair 53.

  FIG. 8 shows a configuration of the slave unit 201 according to the present embodiment. The subunit | mobile_unit 201 is the structure by which the terminal pair 249, the switch 267, and the electric current detection part 268 were added to the subunit | mobile_unit 200. FIG. The terminal pair 249 includes a terminal 247 and a terminal 248. Terminal 247 is connected to communication line 31. Further, the terminal 247 is connected to the connection point 265 via the switch 267. Terminal 248 is connected to communication line 32. The terminal 248 is connected to the connection point 266 via the switch 267.

  The switch 267 is provided between the terminal 247 and the connection point 265, and between the terminal 248 and the connection point 266. The switch 267 is in a conductive / non-conductive state between the terminal 247 and the connection point 265, and the terminal 248. And the connection / disconnection point 266 are controlled. The switch 267 is controlled to be in a conductive / non-conductive state according to control by the control unit 230. The current detection unit 268 detects a current flowing between the terminal 247 and the connection point 265, that is, a current flowing in the communication line pair 33. The current detection unit 268 supplies a voltage signal indicating the magnitude of the detected current to the comparison unit 270.

  Next, the operation of the communication system 1100 will be described. The subunit | mobile_unit 201 detects a 3rd electric current after the process of step S304 in the miswiring detection process shown in FIG. The third current is a current detected by the current detection unit 268. Moreover, the subunit | mobile_unit 201 discriminate | determines in step S305 whether two electric currents among a 1st electric current, a 2nd electric current, and a 3rd electric current are more than a threshold value. And the subunit | mobile_unit 201 controls the switch corresponding to the electric current which is not the maximum among the electric current more than a threshold value to an open state.

  For example, when all of the first current, the second current, and the third current are equal to or greater than the threshold value, and the first current is larger than any of the second current and the third current, the second current The switch 262 corresponding to the current and the switch 267 corresponding to the third current are controlled to be open. According to such control, it can be expected that all the routes that are not the shortest of the routes connecting the child device 201 and the parent device 100 are disconnected from the child device 201 and the loop wiring due to erroneous wiring is eliminated.

  In the configuration shown in FIG. 7, there is only one path connecting slave unit 201 and master unit 100, and no loop wiring exists between slave unit 201 and master unit 100. Accordingly, no erroneous wiring is detected in the erroneous wiring detection process executed by the slave unit 201. However, there are a plurality of routes in the route connecting child device 300 and parent device 100, the route connecting child device 400 and parent device 100, and the route connecting child device 500 and parent device 100. Therefore, an erroneous wiring is detected in the erroneous wiring detection process executed by the slave unit 300, the slave unit 400, and the slave unit 500.

  For example, it is assumed that the slave unit 300 among the slave units 300, 400, and 500 executes the miswiring detection process earliest. In this case, in the miswiring detection process executed by the slave unit 300, the route 1 from the terminal pair 345 to the master unit 100 is 50 m + 20 m = 70 m, and the route 2 from the terminal pair 346 to the master unit 100 is 40 m + 30 m + 30 m + 20 m = 120 m. . For this reason, from the subunit | mobile_unit 300, the communication line pair 53 is cut | disconnected and the path | route 2 is cut | disconnected. In this case, the length of the route from the parent device 100 to all the child devices is 100 m or less, and the processing is completed.

  On the other hand, for example, it is assumed that the slave unit 400 among the slave units 300, 400, and 500 executes the miswiring detection process earliest. In this case, in the erroneous wiring detection process executed by the slave unit 400, the route 1 from the terminal pair 445 to the parent device 100 is 30 m + 20 m = 50 m, and the route 2 from the terminal pair 446 to the parent device 100 is 30 m + 40 m + 50 m + 20 m = 140 m. . For this reason, from the subunit | mobile_unit 400, the communication line pair 43 is cut | disconnected and the path | route 2 is cut | disconnected. In this case, the length of the route from the child device 500 to the parent device 100 is 40 m + 50 m + 20 m = 110 m, which exceeds 100 m. Accordingly, communication between the parent device 100 and the child device 500 becomes impossible.

  Therefore, under the control of the parent device 100, the disconnection of the path 2 by the child device 400 is released, and the erroneous wiring detection process by the child device 500 is executed. In this case, in the erroneous wiring detection process executed by the slave unit 500, the route 1 from the terminal pair 545 to the master unit 100 is 30m + 30m + 20m = 80m, and the route 2 from the terminal pair 546 to the master unit 100 is 40m + 50m + 20m = 110m. . For this reason, from the subunit | mobile_unit 500, the communication line pair 53 is cut | disconnected and the path | route 2 is cut | disconnected. In this case, the length of the route from the parent device 100 to all the child devices is 100 m or less, and the processing is completed.

  In this embodiment, when an incorrect wiring is detected by any of the slave units, a communication line pair that is likely to cause the incorrect wiring is disconnected. Therefore, according to the present embodiment, it can be expected to automatically and appropriately eliminate the influence of erroneous wiring.

(Modification)
As mentioned above, although embodiment of this invention was described, when implementing this invention, a deformation | transformation and application with a various form are possible.

  In the present invention, which part of the configuration, function, and operation described in the above embodiment is adopted is arbitrary. Further, in the present invention, in addition to the configuration, function, and operation described above, further configuration, function, and operation may be employed.

  In the first embodiment, an example in which a communication line pair is automatically disconnected when an erroneous wiring is detected has been described. In the present invention, when erroneous wiring is detected, other processing may be executed. For example, when erroneous wiring is detected, data indicating that erroneous wiring has been detected may be transmitted from the slave device that has detected erroneous wiring to the parent device 100. In this case, for example, base unit 100 can notify the user of information indicating that a miswiring has been detected via light, image, or sound via notification unit 150. In addition to the process of automatically disconnecting the communication line pair, a process of notifying the user that an erroneous wiring has been detected may be executed.

  In the first embodiment, the example in which the switch 261 is one double-sided switch has been described. In the present invention, the switch 261 may be configured by two switch groups, that is, a switch disposed between the terminal 241 and the connection point 265 and a switch disposed between the terminal 242 and the connection point 266. Good. In this case, the conduction / non-conduction state of the two switch groups is controlled simultaneously. The switch 262 may also be configured by two switch groups instead of the double switch.

  In the first embodiment, an example in which the communication system 1000 is a lighting system, the parent device 100 is a lighting control device, and the child device 200, the child device 300, the child device 400, and the child device 500 are lighting devices has been described. In the present invention, the communication system may of course be another system. For example, the communication system 1000 may be an air conditioning system, the master unit 100 may be an outdoor unit, and the slave unit 200, the slave unit 300, the slave unit 400, and the slave unit 500 may be indoor units. Of course, the number of the plurality of slave units is not limited to four.

  In the first embodiment, the example in which the control unit 230, the comparison unit 270, and the signal output unit 280 are separated has been described. In the present invention, the control unit 230, the comparison unit 270, and the signal output unit 280 may not be separated. For example, the comparison unit 270 and the signal output unit 280 may be incorporated in the control unit 230, and the control unit 230 may have the function of the comparison unit 270 and the function of the signal output unit 280. In this case, the miswiring detection signal may be a signal output to a component inside the control unit 230 instead of a signal output to the outside of the control unit 230. For example, the miswiring detection signal may be an interrupt signal for generating an interrupt to be executed when miswiring is detected, or a flag writing signal for writing a flag indicating that miswiring has been detected. . Further, the miswiring detection signal may be a control signal for the switch 261 or the switch 262.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. Further, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

  The present invention is applicable to a communication system in which a parent device and a plurality of child devices communicate.

11, 12, 21, 22, 31, 32, 31, 41, 42, 51, 52 Communication line, 13, 23, 33, 43, 53 Communication line pair, 100, 101 Base unit, 110, 210 Transmission circuit, 111 , 113, 211 NPN transistor, 112, 114 PNP transistor, 120, 220 receiver circuit, 121, 161, 291 power supply terminal, 122 operational amplifier, 123, 162 capacitor, 124, 125, 126, 212, 222, 223 resistance, 127, 128,163 ground terminal, 130,230 control unit, 141,142,143,144,241,242,243,244,247,248,341,342,343,344,441,442,443,444,541 542, 543, 544 terminals, 145, 146, 245, 246 249, 345, 346, 445, 446, 545, 546 Terminal pair, 150 notification unit, 200, 201, 300, 400, 500 cordless handset, 221 Zener diode, 250 rectifier circuit, 251, 252, 253, 254 diode, 261 , 262, 267 switch, 263, 264, 268 current detection unit, 265, 266 connection point, 270 comparison unit, 280 signal output unit, 1000, 1100 communication system

Claims (6)

A communication system comprising a master unit and a plurality of slave units, wherein the master unit and the plurality of slave units are mutually connected by a plurality of communication line pairs,
The base unit is
A receiving circuit that receives data from the plurality of slave units by detecting the presence or absence of current flowing through the communication line pair connected to the master unit among the plurality of communication line pairs;
The plurality of slave units are:
A first terminal pair to which a first communication line pair among the plurality of communication line pairs is connected;
A second terminal pair to which a second communication line pair is connected among the plurality of communication line pairs;
A first connection point to which one terminal of the first terminal pair and one terminal of the second terminal pair are connected; the other terminal of the first terminal pair; and the second terminal. A transmission circuit that transmits data to the master unit by controlling a conduction / non-conduction state between the second connection point to which the other terminal of the terminal pair is connected;
First current detection means for detecting a first current flowing in the first communication line pair;
Second current detection means for detecting a second current flowing in the second communication line pair;
When the first connection point and the second connection point are controlled to be in a conductive state when the first current and the second current are equal to or greater than a predetermined threshold, Signal output means for outputting a predetermined signal,
Communications system. The plurality of slave units are:
Controls a short circuit / open state between the one terminal of the first terminal pair and the first connection point, and controls the other terminal of the first terminal pair and the second connection. A first switch for controlling a short circuit / open state between the points;
The second terminal pair controls a short circuit / open state between the one terminal and the first connection point, and the other terminal and the second connection of the second terminal pair. A second switch for controlling a short circuit / open state between the points;
Control means for controlling one of the first switch and the second switch to an open state when the signal is output from the signal output means;
The communication system according to claim 1. When the signal is output from the signal output means, the control means controls the first switch to be in an open state when the first current is smaller than the second current, and the signal output When the signal is output from the means, and the second current is smaller than the first current, the second switch is controlled to be open.
The communication system according to claim 2. The parent device includes a transmission circuit that transmits data to the plurality of child devices by switching a polarity of a voltage applied between a pair of communication lines connected to the parent device,
The plurality of slave units includes a reception circuit that receives data from the master unit by detecting a polarity of a voltage applied between the first connection point and the second connection point,
When the plurality of slave units control the one switch to an open state, the control unit transmits data indicating control completion to the master unit,
When the master unit receives data indicating the completion of control from the first slave unit among the plurality of slave units, it transmits data requesting a response to the plurality of slave units,
The plurality of slave units, when receiving data requesting the response from the master unit, transmits data indicating a response to the master unit,
When there is a second slave unit that does not receive data indicating the response among the plurality of slave units, the master unit transmits data requesting control release to the first slave unit,
When the first slave unit receives the data for requesting the control release from the master unit, the one slave unit is controlled to be in a short-circuit state, and the data indicating the completion of the control release is transmitted to the master unit,
When the master unit receives data indicating the completion of control release from the first slave unit, the master unit transmits data requesting the response to the second slave unit.
The communication system according to claim 3. A communication device that is one of a plurality of slave devices communicating with a master device,
The master unit and the plurality of slave units are connected to each other by a plurality of communication line pairs,
Two or more communication line pairs connected to the same slave unit among the plurality of communication line pairs are connected to each other,
A voltage is applied by the master unit between the communication line pairs connected to the master unit among the plurality of communication line pairs,
The communication device is:
A first terminal pair to which a first communication line pair among the plurality of communication line pairs is connected;
A second terminal pair to which a second communication line pair is connected among the plurality of communication line pairs;
A first connection point to which one terminal of the first terminal pair and one terminal of the second terminal pair are connected; the other terminal of the first terminal pair; and the second terminal. A transmission circuit that transmits data to the master unit by controlling a conduction / non-conduction state between the second connection point to which the other terminal of the terminal pair is connected;
First current detection means for detecting a first current flowing in the first communication line pair;
Second current detection means for detecting a second current flowing in the second communication line pair;
When the first connection point and the second connection point are controlled to be in a conductive state when the first current and the second current are equal to or greater than a predetermined threshold, Signal output means for outputting a predetermined signal,
Communication equipment. A miswiring detection method in a communication system comprising a master unit and a plurality of slave units, wherein the master unit and the plurality of slave units are mutually connected by a plurality of communication line pairs,
Connecting two or more communication line pairs connected to the same slave unit among the plurality of communication line pairs,
A voltage is applied between a pair of communication lines connected to the parent device among the plurality of communication line pairs,
A first terminal connected to one terminal of a first terminal pair included in the first slave unit and a second terminal pair included in the first slave unit among the plurality of slave units. And a second connection point where the other terminal of the first terminal pair and the other terminal of the second terminal pair are connected to each other,
Of the plurality of communication line pairs, the first current flowing through the first communication line pair connected to the first terminal pair, and to the second terminal pair among the plurality of communication line pairs. When the second current flowing through the second communication line pair is equal to or greater than a predetermined threshold, a predetermined signal is output.
Incorrect wiring detection method.

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