Electronic apparatus and short circuit detection method

Abstract

To provide an electronic apparatus for identifying a place at which a short circuit causing an earth fault has been generated.SOLUTION: An electronic apparatus has an insulated power circuit, a common line, an input-output circuit, a feeder line, a short circuit current detection part, and a short circuit detection part. The insulated power circuit includes a pair of input ends into which a DC voltage is input and a pair of output ends, and converts the DC voltage to an output voltage with a predetermined voltage so as to output it from the output ends, and one of the pair of input ends is earthed. The common line is connected to one of the pair of output ends so as to supply a reference voltage. The input-output circuit is connected to the common line, and performs one of an input and an output of a signal between an external device and itself. The feeder line supplies power to the input-output circuit, and has an earth fault detection circuit connected thereto. The short circuit current detection part detects a short circuit current flowing on the earth side through the earth fault detection circuit when the input ends and the output ends of the insulated power circuit are short-circuited. The short circuit detection part detects a short circuit on the basis of a detection result of the short circuit current detection part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an electronic device and a short-circuit detection method in the electronic device.

Background Art

[0002] In electronic devices used in plants, factories, etc., a system has been proposed that includes a ground fault detection circuit to detect ground fault accidents (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the above conventional technology has a problem that it is impossible to specify the location where a short circuit causing a ground fault has occurred.

[0005] Therefore, the present disclosure proposes an electronic device that specifies the location where a short circuit causing a ground fault has occurred and a short-circuit detection method in the electronic device.

Means for Solving the Problems

[0006] The electronic device of the present disclosure includes an insulated power supply circuit, a common line, an input / output circuit, a power supply line, a short-circuit current detection unit, and a short-circuit detection unit. The insulated power supply circuit includes a pair of input terminals and a pair of output terminals to which a DC voltage is input, converts the DC voltage into an output voltage of a predetermined voltage, outputs the output voltage from the output terminals, and one of the pair of input terminals is grounded. The common line is connected to one of the pair of output terminals to supply a reference voltage. The input / output circuit is connected to the common line and performs at least one of signal input and signal output with an external device. The power supply line supplies power to the input / output circuit and is connected to a ground fault detection circuit. The short-circuit current detection unit detects a short-circuit current flowing to the ground side through the ground fault detection circuit when the input terminal and the output terminal of the insulated power supply circuit are short-circuited. The short-circuit detection unit detects a short circuit based on the detection result of the short-circuit current detection unit.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. In each of the following embodiments, the same parts are denoted by the same reference numerals, and redundant descriptions are omitted. 1. First Embodiment 2. Second Embodiment 3. Third Embodiment 4. Fourth Embodiment 5. Fifth Embodiment

[0009] (1. First Embodiment) [Configuration of I / O Module] FIG. 1 is a diagram showing a configuration example of an I / O module according to a first embodiment of the present disclosure. The figure is a circuit diagram showing a configuration example of the I / O module 10. The I / O module 10 exchanges signals with field devices such as measuring instruments in a factory or the like. The I / O module 10 in the figure shows an example in which a contact signal is input. Note that the I / O module 10 includes circuits based on the respective potentials of the system potential (primary side) and the field potential (secondary side), and these circuits are insulated by an insulating portion. A field circuit power supply 60 and a ground fault detection circuit 70 are connected to the field side of the I / O module 10. Note that the I / O module 10 is an example of the "electronic device" of the present disclosure.

[0010] The I / O module 10 includes an isolated power supply circuit 20, a capacitor 13, a control unit 14, an input / output circuit 16, a common line 11, power supply lines (a high-potential power supply line 61 and a low-potential power supply line 62), a resistor 15, a short-circuit current detection unit 17, and a short-circuit detection unit 18.

[0011] The isolated power supply circuit 20 is an isolated power supply circuit that converts an input DC voltage into an output voltage of a predetermined voltage and outputs it. The isolated power supply circuit 20 includes a pair of input terminals (a high-potential input terminal 21 and a low-potential input terminal 22) to which a DC voltage is input and a pair of output terminals (a high-potential output terminal 23 and a low-potential output terminal 24). The isolated power supply circuit 20 in the figure shows an example configured by a DC-DC converter insulated by a transformer. The primary side circuit of the transformer is configured by a push-pull type circuit. The secondary side of the transformer is configured by a bridge rectifier circuit.

[0012] The isolated power supply circuit 20 is supplied with a DC voltage from the system circuit power supply 50. The high-potential side terminal of the system circuit power supply 50 is connected to the high-potential input terminal 21 via the high-potential power supply line 51. The low-potential side terminal of the system circuit power supply 50 is connected to the low-potential input terminal 22 via the low-potential power supply line 52. Note that one of the input terminals is grounded. In the system in the figure, the low-potential power supply line 52 is grounded. Note that the high-potential power supply line 51 and the low-potential power supply line 52 are examples of the "second power supply line" of the present disclosure.

[0013] The high - potential output terminal 23 is connected to the power supply line 12. The power supply line 12 is a wiring for supplying power to the field - side circuit of the I / O module 10. The low - potential output terminal 24 is connected to the common line 11. The common line 11 is connected to what is called a circuit common and is a wiring for transmitting a reference potential. A capacitor 13 is connected between the power supply line 12 and the common line 11. This capacitor 13 smoothes the output voltage of the isolated power supply circuit 20.

[0014] Note that, for example, an isolated power supply circuit composed of an IC (Integrated Circuit) incorporating a magnetic isolation element can also be applied to the isolated power supply circuit 20.

[0015] The control unit 14 controls various state quantities (such as pressure, temperature, flow rate, etc.) in an industrial process. The control unit 14 in the figure receives a signal input from the field circuit 63. Note that the signal input from the field circuit 63 is transmitted via the input / output circuit 16. The control unit 14 can be constituted by, for example, a microcomputer. The power supply line 12 and the common line 11 are connected to the control unit 14.

[0016] The input / output circuit 16 performs at least one of signal input and signal output between the external device. The field circuit 63 in the figure corresponds to this external device. The input / output circuit 16 in the figure shows an example where a signal is input from the field circuit 63. The input / output circuit 16 transmits the input signal from the field circuit 63 to the control unit 14 via an isolation element such as a photocoupler. The arrow from the input / output circuit 16 to the control unit 14 represents this signal transmission. Also, the input / output circuit 16 is connected to the common line 11. The input / output circuit 16 in the figure shows an example of being connected to the common line 11 via a resistor 15.

[0017] The I / O module 10 is connected to power supply lines (high-potential power supply line 61 and low-potential power supply line 62). These power supply lines are wiring for supplying power from the field circuit power supply 60. The high-potential terminal of the field circuit power supply 60 is connected to the high-potential power supply line 61, and the low-potential terminal of the field circuit power supply 60 is connected to the low-potential power supply line 62. The high-potential power supply line 61 is connected to the input / output circuit 16 to supply power to the input / output circuit 16. Also, the low-potential power supply line 62 is connected to the common line 11 inside the I / O module 10.

[0018] The high-potential power supply line 61 and the low-potential power supply line 62 are also connected to the field circuit 63. As described above, the field circuit 63 inputs a contact signal to the input / output circuit 16. This contact signal can be generated by, for example, a relay contact.

[0019] Further, a ground fault detection circuit 70 is connected to the high-potential power supply line 61 and the low-potential power supply line 62. This ground fault detection circuit 70 detects a ground fault based on a ground fault current. The ground fault detection circuit 70 includes a resistor 71, a resistor 72, and an ammeter 73. The resistor 71 and the resistor 72 are connected in series. These resistor 71 and resistor 72 are connected between the high-potential power supply line 61 and the low-potential power supply line 62. One end of the ammeter 73 is connected to the midpoint of the resistor 71 and the resistor 72. The other end of the ammeter 73 is grounded.

[0020] The resistor 15 is a resistor inserted into the common line 11. As described above, the control unit 14 and the input / output circuit 16 are driven by different power supplies. Also, a signal from the input / output circuit 16 is transmitted to the control unit 14 via an insulating element. For this reason, no current flows through the resistor 15 during normal operation. However, when a short-circuit accident occurs between the input terminal and the output terminal of the insulation power supply circuit 20, a short-circuit current flows through the resistor 15. This is because the low-potential power supply line 52 and the ground fault detection circuit 70 are grounded. When the input terminal and the output terminal of the insulation power supply circuit 20 are short-circuited, a ground fault current flows from the ground connection point of the ground fault detection circuit 70 to the ground connection point of the low-potential power supply line 52. Inside the I / O module 10, this ground fault current becomes a short-circuit current flowing through the resistor 15.

[0021] There are four possible paths for a short circuit between the input terminal and the output terminal of the isolation power supply circuit 20. Specifically, the high potential input terminal 21 - the high potential output terminal 23 (the dotted path in the figure), the high potential input terminal 21 - the low potential output terminal 24 (the dashed path in the figure), the low potential input terminal 22 - the low potential output terminal 24 (the dashed-dotted path in the figure), and the low potential input terminal 22 - the high potential output terminal 23 (the double-dashed path in the figure).

[0022] The short-circuit current detection unit 17 detects the short-circuit current flowing to the ground side via the ground fault detection circuit 70 when the input terminal and the output terminal of the isolation power supply circuit 20 are short-circuited. The short-circuit current detection unit 17 in the figure detects the current flowing through the resistor 15 as the short-circuit current. Specifically, the short-circuit current detection unit 17 in the figure detects the short-circuit current by detecting the terminal voltage of the resistor 15. The short-circuit current detection unit 17 can be constituted by, for example, a differential amplifier circuit.

[0023] The short-circuit detection unit 18 detects a short circuit based on the detection result of the short-circuit current detection unit 17. The short-circuit detection unit 18 in the figure detects a short circuit by comparing the voltage of the resistor 15 output from the short-circuit current detection unit 17 with a threshold value. The voltage source 19 in the figure supplies the threshold value. The short-circuit detection unit 18 can detect a short circuit when the output voltage of the short-circuit current detection unit 17 exceeds the threshold value. Further, when detecting a short circuit, the short-circuit detection unit 18 generates and outputs a short-circuit detection signal.

[0024] FIG. 2 is a diagram showing an example of an equivalent circuit of the I / O module according to the first embodiment of the present disclosure. The figure is a circuit diagram representing the equivalent circuit of the I / O module 10. The circuit in the figure shows the system circuit power supply 50, the primary side circuit 25 of the isolation power supply circuit 20, the DC power supply 26 constituting the secondary side circuit of the isolation power supply circuit 20, the control unit 14, the input / output circuit 16, the field circuit power supply 60, the resistor 15, and the resistors 71 and 72 of the ground fault detection circuit 70.

[0025] Figures 3A - 3D are diagrams showing an example of a short - circuit current according to the first embodiment of the present disclosure. Figures 3A - 3D are diagrams representing the short - circuit current in the equivalent circuit of the I / O module 10. In Figures 3A - 3D, the dotted arrows represent the paths of the short - circuit current.

[0026] Figure 3A shows an example when the high - potential input terminal 21 and the high - potential output terminal 23 are short - circuited. This figure represents the case where the short - circuit represented by the dotted line in Figure 1 occurs. The short - circuit current is divided and flows through the paths of system - circuit power supply 50 - control unit 14 - resistor 15 - field - circuit power supply 60 - resistor 71 and system - circuit power supply 50 - control unit 14 - resistor 15 - resistor 72. The current of each path is described in this figure.

[0027] Figure 3B shows an example when the low - potential input terminal 22 and the high - potential output terminal 23 are short - circuited. This figure represents the case where the short - circuit represented by the two - dotted line in Figure 1 occurs. The short - circuit current is divided and flows through the paths of field - circuit power supply 60 - resistor 71 - DC power supply 26 - resistor 15 and field - circuit power supply 60 - resistor 71 - resistor 72. The current of each path is described in this figure.

[0028] Figure 3C shows an example when the high - potential input terminal 21 and the low - potential output terminal 24 are short - circuited. This figure represents the case where the short - circuit represented by the broken line in Figure 1 occurs. The short - circuit current is divided and flows through the paths of system - circuit power supply 50 - resistor 15 - field - circuit power supply 60 - resistor 71 and system - circuit power supply 50 - resistor 15 - resistor 72. The current of each path is described in this figure.

[0029] Figure 3D shows an example when the low - potential input terminal 22 and the low - potential output terminal 24 are short - circuited. This figure represents the case where the short - circuit represented by the one - dotted line in Figure 1 occurs. The short - circuit current flows through the path of field - circuit power supply 60 - resistor 71 - resistor 15. The current of this path is described in this figure.

[0030] As shown in FIGS. 3A - 3D, the short - circuit current changes according to the location where the short - circuit occurs. Therefore, the short - circuit location can also be identified based on the short - circuit current.

[0031] FIG. 4 is a diagram showing an example of the short - circuit current of the I / O module according to the first embodiment of the present disclosure. This figure shows the short - circuit current in each case of FIGS. 3A - 3D.

[0032] When the high - potential input terminal 21 - high - potential output terminal 23 is short - circuited (FIG. 3A), the current through R15 is (V2 + 2×V0−2×V1) / R. Here, V0 represents the voltage of the system - circuit power supply 50. V1 represents the voltage of the DC power supply 26. V2 represents the voltage of the field - circuit power supply 60. R represents the resistance values of the resistors 71 and 72. Also, the voltage across the resistor 15 is (V2 + 2×V0−2×V1)×Rs / R. Here, Rs represents the resistance value of the resistor 15.

[0033] When the low - potential input terminal 22 - high - potential output terminal 23 is short - circuited (FIG. 3B), the current through R15 is (V2−2×V1) / R. Also, the voltage across the resistor 15 is (V2−2×V1)×Rs / R.

[0034] When the high - potential input terminal 21 - low - potential output terminal 24 is short - circuited (FIG. 3C), the current through R15 is (V2 + 2×V0) / R. Also, the voltage across the resistor 15 is (V2 + 2×V0)×Rs / R.

[0035] When the low - potential input terminal 22 - low - potential output terminal 24 is short - circuited (FIG. 3D), the current through R15 is V2 / R. Also, the voltage across the resistor 15 is V2×Rs / R.

[0036] The short - circuit detection unit 18 in FIG. 1 can detect a short - circuit based on the signal voltage from the short - circuit current detection unit 17 and can also identify (detect) the short - circuit location according to the signal voltage. Specifically, the short - circuit detection unit 18 compares this signal voltage with the voltage across each R15 shown in FIG. 4, and can detect the short - circuit location by selecting the voltage across R15 that is close to the signal voltage.

[0037] [Short - circuit detection process] FIG. 5 is a diagram showing an example of the processing procedure of the short - circuit detection process according to the first embodiment of the present disclosure. This figure is a flowchart representing an example of the processing procedure of the short - circuit detection process in the I / O module 10. First, the short - circuit current detection unit 17 detects a short - circuit current (step S101). This can be done by the short - circuit current detection unit 17 detecting the voltage of the resistor 15. Next, the short - circuit detection unit 18 determines whether the short - circuit current, which is the detection result of the short - circuit current detection unit 17, is greater than the threshold value (step S102). As a result, if the short - circuit current is greater than the threshold value (step S102, Yes), the short - circuit detection unit 18 determines that a short - circuit has occurred. The short - circuit detection unit 18 generates a short - circuit detection signal (step S103) and terminates the process. On the other hand, in step S102, if the short - circuit current is not greater than the threshold value (step S102, No), the short - circuit detection unit 18 determines that no short - circuit has occurred and terminates the process.

[0038] In addition, in the above - mentioned process, the short - circuit detection unit 18 can also detect the short - circuit location according to the short - circuit current.

[0039] Also, when the short - circuit detection unit 18 detects the above - mentioned short - circuit, it can determine that there is a short - circuit accident (internal ground fault) inside the I / O module 10. On the other hand, when the ground - fault detection circuit 70 detects a ground - fault in a state where no short - circuit is detected, the short - circuit detection unit 18 can determine that there is a short - circuit accident (external ground fault) outside the I / O module 10.

[0040] Note that the configuration of the I / O module 10 of the present disclosure is not limited to this example. For example, a current sensor using a Hall element or the like instead of the resistor 15 can be used as the detection element for the short - circuit current. Also, this current sensor and the resistor 15 can be regarded as a current detection unit. In this case, the short - circuit current detection unit 17 detects the short - circuit current based on the output of this current detection unit.

[0041] In addition to the insulated power supply circuit 20, there are various elements that insulate the primary-secondary side. For example, there are photocouplers, capacitors, and the like. In the present disclosure, short-circuit failures of these can also be detected.

[0042] As described above, the I / O module 10 of the first embodiment of the present disclosure can detect a short-circuit failure. Thereby, the reliability of the system can be improved.

[0043] (2. Second Embodiment) The I / O module 10 of the first embodiment described above detected a short circuit based on the voltage of the resistor 15. In contrast, the I / O module 10 of the second embodiment of the present disclosure is different from the first embodiment described above in that it reduces noise during short-circuit detection.

[0044] [Configuration of I / O Module] FIG. 6 is a diagram showing a configuration example of an I / O module according to the second embodiment of the present disclosure. This figure is a circuit diagram showing a configuration example of the I / O module 10, similar to FIG. 1. Note that some descriptions are omitted in this figure. The I / O module 10 in this figure is different from the I / O module 10 in FIG. 1 in that it further includes a low-pass filter 40.

[0045] The low-pass filter 40 attenuates high-frequency components of the output signal of the short-circuit current detection unit 17. In the I / O module 10, the short-circuit current is assumed to be a current close to direct current. Therefore, by arranging the low-pass filter 40 to attenuate the high-frequency components of the output signal of the short-circuit current detection unit 17, noise can be reduced. Also, when a signal current flows through the resistor 15, for example, even when the input / output circuit 16 transmits a signal to the control unit 14 without passing through an insulating element, it is possible to detect the short-circuit current.

[0046] Since the configuration of the I / O module 10 other than this is the same as the configuration of the I / O module 10 in the first embodiment of the present disclosure, the description thereof is omitted.

[0047] As described above, the I / O module 10 of the second embodiment of the present disclosure can reduce noise during short-circuit current detection. Thereby, the accuracy of short-circuit current detection can be improved.

[0048] (3. Third Embodiment) The I / O module 10 of the first embodiment described above detected the current of the resistor 15 inserted in the common line 11 as the short-circuit current. In contrast, the I / O module 10 of the third embodiment of the present disclosure is different from the first embodiment described above in that it detects the current of resistors arranged at different positions.

[0049] [Configuration of I / O Module] FIG. 7 is a diagram showing a configuration example of an I / O module according to the third embodiment of the present disclosure. This figure is a circuit diagram showing a configuration example of the I / O module 10, similar to FIG. 1. The I / O module 10 in this figure is different from the I / O module 10 in FIG. 1 in that it includes resistors 31 and 32 instead of the resistor 15, and includes short-circuit current detection units 33 and 34 instead of the short-circuit current detection unit 17.

[0050] The resistor 31 is inserted into the high-potential power supply line 51. Also, the resistor 32 is inserted into the low-potential power supply line 52. The short-circuit current detection unit 33 detects the current flowing through the resistor 31 as the short-circuit current. Also, the short-circuit current detection unit 34 detects the current flowing through the resistor 32 as the short-circuit current.

[0051] The short-circuit detection unit 18 in this figure uses the difference between the output signal of the short-circuit current detection unit 33 and the output signal of the short-circuit current detection unit 34 as the short-circuit current, compares it with a threshold value, and detects a short circuit.

[0052] [Other Configurations of I / O Module] FIG. 8 is a diagram showing another configuration example of an I / O module according to the third embodiment of the present disclosure. This figure is a circuit diagram showing a configuration example of the I / O module 10, similar to FIG. 7. The I / O module 10 in this figure is different from the I / O module 10 in FIG. 7 in that the resistors 31 and 32 are arranged on the secondary side of the isolation power supply circuit 20.

[0053] The resistor 31 in the figure is inserted into the power supply line 12. Also, the resistor 32 in the figure is inserted into the common line 11 close to the low potential output terminal 24.

[0054] Since the configuration of the I / O module 10 other than this is the same as the configuration of the I / O module 10 in the first embodiment of the present disclosure, the description thereof is omitted.

[0055] In this way, the I / O module 10 of the third embodiment of the present disclosure detects a short circuit based on the currents of the resistors 31 and 32 arranged in the wiring close to the insulated power supply circuit 20.

[0056] (4. Fourth Embodiment) The I / O module 10 of the above-described first embodiment generates a short circuit detection signal when detecting a short circuit. In contrast, the I / O module 10 of the fourth embodiment of the present disclosure is different from the above-described first embodiment in that the generated short circuit detection signal is output outside the I / O module 10.

[0057] [Configuration of I / O Module] FIG. 9 is a diagram showing a configuration example of an I / O module according to the fourth embodiment of the present disclosure. This figure, like FIG. 1, is a circuit diagram showing a configuration example of the I / O module 10. The I / O module 10 in this figure is different from the I / O module 10 in FIG. 1 in that it further includes a microcomputer 36 and an insulating element 35.

[0058] The insulating element 35 transmits the short circuit detection signal in the short circuit detection unit 18 in an insulated state. For example, a photocoupler can be applied to the insulating element 35. The insulating element 35 transmits the short circuit detection signal from the short circuit detection unit 18 to the microcomputer 36.

[0059] The microcomputer 36 generates abnormal information based on the short-circuit detection signal transmitted via the insulating element 35 and transmits it to an external device. The microcomputer 36 stores, for example, the information on short-circuit detection as data in an internal register. The external device can acquire the presence or absence of an abnormal state by reading the data in this register. As a reading mechanism, a digital communication line 37 for exchanging the control signal of the I / O module 10 and the register information of the microcomputer 36 in the I / O module 10 can be used.

[0060] FIG. 10 is a diagram showing a configuration example of a system according to a fourth embodiment of the present disclosure. The figure represents a configuration example of a system including a plurality of I / O modules 10. The system 1 includes a plurality of I / O modules 10 (I / O module 10a, I / O module 10b, and I / O module 10c). High-potential power supply lines 51 and low-potential power supply lines 52 from the system circuit power supply 50 and high-potential power supply lines 61 and low-potential power supply lines 62 from the field circuit power supply 60 are commonly connected to these I / O modules 10a, 10b, and 10c. Further, the respective communication lines 37 of the I / O modules 10a, 10b, and 10c are bus-connected and connected to the control device 80.

[0061] The control device 80 checks the abnormal information from each I / O module 10. When an abnormality is detected, the control device 80 can notify the user, such as by a monitor, which I / O module 10 the abnormality was detected in. In this case, the user can replace only the I / O module 10 in which the abnormality has occurred without stopping the entire system 1. Thus, by adopting the configuration of the system 1 in the figure, convenience can be improved.

[0062] [Other configurations of the I / O module] FIG. 11 is a diagram showing another configuration example of the I / O module according to the fourth embodiment of the present disclosure. This figure is a circuit diagram showing a configuration example of the I / O module 10, similar to FIG. 9. The I / O module 10 in this figure is different from the I / O module 10 in FIG. 9 in that it includes a signal generation circuit 38 instead of the microcomputer 36.

[0063] The signal generation circuit 38 generates an abnormality detection signal to be output to the outside of the I / O module 10. The signal generation circuit 38 outputs the generated abnormality detection signal to the signal line 39.

[0064] FIG. 12 is a diagram showing another configuration example of the system according to the fourth embodiment of the present disclosure. This figure is a diagram showing a configuration example of the system 1, similar to FIG. 10. The system 1 in this figure is different from the system 1 in FIG. 10 in that it further includes a digital input module 81.

[0065] The digital input module 81 detects the respective abnormality detection signals of the I / O module 10a, the I / O module 10b, and the I / O module 10c. Signal lines 39a, 39b, and 39c of the I / O module 10a, the I / O module 10b, and the I / O module 10c are respectively wired to the digital input module 81, and the abnormality detection signals are individually input. The digital input module 81 outputs the detection results of these abnormality detection signals to the control device 80.

[0066] Since the configuration of the I / O module 10 other than this is the same as the configuration of the I / O module 10 in the first embodiment of the present disclosure, the description thereof is omitted.

[0067] As described above, the I / O module 10 according to the fourth embodiment of the present disclosure can output an abnormality detection signal to an external device.

[0068] (5. Fifth Embodiment) The I / O module 10 of the above-described first embodiment detected a short circuit. In contrast, the I / O module 10 of the fifth embodiment of the present disclosure is different from the above-described first embodiment in that when a short circuit is detected, the supply of power from the system circuit power supply 50 is stopped.

[0069] [Configuration of I / O Module] FIG. 13 is a diagram showing a configuration example of an I / O module according to the fifth embodiment of the present disclosure. This figure is a circuit diagram showing a configuration example of the I / O module 10, similar to FIG. 1. The I / O module 10 in this figure is different from the I / O module 10 in FIG. 1 in that it further includes switch elements 41 and 42 and an insulating element 35.

[0070] The switch element 41 is a switch element inserted into the high-potential power supply line 51. The switch element 42 is a switch element inserted into the low-potential power supply line 52. The switch elements 41 and 42 are in a conductive state during normal operation. When a short-circuit detection signal is input from the short-circuit detection unit 18 via the insulating element 35, the switch elements 41 and 42 shift to a non-conductive state. Thereby, the I / O module 10 can be turned off, and the short-circuit current and the ground fault current can be blocked. Note that the switch elements 41 and 42 are an example of the "stop unit" of the present disclosure.

[0071] Since the configuration of the I / O module 10 other than this is the same as the configuration of the I / O module 10 in the first embodiment of the present disclosure, the description thereof is omitted.

[0072] As described above, the I / O module 10 of the fifth embodiment of the present disclosure can stop the supply of power to the I / O module 10 when a short circuit is detected. Thereby, the reliability of the system can be improved.

[0073] This embodiment can adopt a cloud computing configuration in which one function is shared and jointly processed by a plurality of devices via a network.

[0074] As described above, each embodiment of the present disclosure has been explained. However, the technical scope of the present disclosure is not limited to the above-described embodiments as they are, and various modifications are possible without departing from the gist of the present disclosure. Also, components from different embodiments and modifications may be appropriately combined.

[0075] In addition, a series of processes performed by each device described in this specification may be realized using any of software, hardware, and a combination of software and hardware. The program constituting the software is, for example, pre-stored in a storage medium (non-transitory media) provided inside or outside each device. And each program is read into RAM when executed by a computer, for example, and executed by a processor such as a CPU.

[0076] Also, the processes described using flowcharts and sequence diagrams in this specification do not necessarily have to be executed in the order shown in the figures. Some process steps may be executed in parallel. Also, additional process steps may be adopted, and some process steps may be omitted.

[0077] Also, the processing procedures described in the above embodiments may be regarded as a method having these series of procedures, or may be regarded as a program for causing a computer to execute these series of procedures or a recording medium storing the program. As this recording medium, for example, a CD (Compact Disc), MD (Mini Disc), DVD (Digital Versatile Disc), memory card, Blu-ray Disc (Blu-ray (registered trademark) Disc), etc. can be used.

[0078] Note that the effects described in this specification are merely examples and are not limiting, and there may be other effects.

[0079] Note that the present technology can also adopt the following configuration. (1) An insulating power supply circuit having a pair of input terminals to which a DC voltage is input and a pair of output terminals, converting the DC voltage into an output voltage of a predetermined voltage and outputting the output voltage from the output terminals, and one of the pair of input terminals being grounded; A common line connected to one of the pair of output terminals to supply a reference voltage; An input / output circuit connected to the common line and performing at least one of signal input and signal output with an external device; A power supply line for supplying power to the input / output circuit and to which a ground fault detection circuit is connected; A short-circuit current detection unit that detects a short-circuit current flowing to the ground side via the ground fault detection circuit when the input terminal and the output terminal of the insulating power supply circuit are short-circuited; A short-circuit detection unit that detects a short circuit based on the detection result of the short-circuit current detection unit An electronic device having the above. (2) The electronic device according to (1) above, wherein the short-circuit current detection unit detects the current flowing through a resistor inserted at a node of either the insulating power supply circuit or the common line as the short-circuit current. (3) Further having a second power supply line for transmitting the DC voltage to the pair of input terminals, The electronic device according to (1) above, wherein the short-circuit current detection unit detects the current flowing through a resistor inserted in the second power supply line as the short-circuit current. The electronic device according to (1) above. (4) The electronic device according to (1) above, wherein the short-circuit current detection unit detects the current flowing through a resistor connected to the pair of output terminals as the short-circuit current. (5) The electronic device according to any one of (1) to (4) above, further having a stop unit that stops the input of the DC voltage to the pair of input terminals of the insulating power supply circuit when the short circuit is detected. (6) The electronic device according to any one of (1) to (5) above, wherein the short-circuit detection unit further detects the short-circuit location. (7) An insulating power supply circuit having a pair of input terminals to which a DC voltage is input and a pair of output terminals, converting the DC voltage into an output voltage of a predetermined voltage and outputting the output voltage from the output terminals, and one of the pair of input terminals being grounded; a common line connected to one of the pair of output terminals for supplying a reference voltage; an input / output circuit connected to the common line and performing at least one of signal input and signal output with an external device; and a power supply line for supplying power to the input / output circuit and to which a ground fault detection circuit is connected, in an electronic device, detecting a short-circuit current flowing to the ground side via the ground fault detection circuit when the input terminal and the output terminal of the insulating power supply circuit are short-circuited; detecting a short circuit based on the result of the detection; A short-circuit detection method including the above.

Explanation of symbols

[0080] 1 System 10, 10a, 10b, 10c I / O module 11 Common line 12 Power supply line 15, 31, 32, 71, 72 Resistor 16 Input / output circuit 17, 33, 34 Short-circuit current detection unit 18 Short-circuit detection unit 20 Insulating power supply circuit 21 High-potential input terminal 22 Low-potential input terminal 23 High-potential output terminal 24 Low-potential output terminal 40 Low-pass filter 41, 42 Switch element 50 Power supply for system circuit 51 High-potential power supply line 52 Low-potential power supply line 60 Power supply for field circuit 61 High-potential power supply line 62 Low-potential power supply line 63 Field circuit 70 Ground fault detection circuit

Claims

1. An insulating power supply circuit having a pair of input terminals to which a DC voltage is input and a pair of output terminals, converting the DC voltage into an output voltage of a predetermined voltage and outputting the output voltage from the output terminals, and one of the pair of input terminals being grounded; A common line connected to one of the pair of output terminals for supplying a reference voltage; An input / output circuit connected to the common line and performing at least one of signal input and signal output with an external device; A power supply line for supplying power to the input / output circuit and to which a ground fault detection circuit is connected; A short-circuit current detection unit that detects a short-circuit current flowing to the ground side via the ground fault detection circuit when the input terminal and the output terminal of the insulating power supply circuit are short-circuited; A short-circuit detection unit that detects a short circuit based on the detection result of the short-circuit current detection unit An electronic device having the above.

2. The electronic device according to claim 1, wherein the short-circuit current detection unit detects the current flowing through a resistor inserted at any node of the insulating power supply circuit and the common line as the short-circuit current.

3. Further having a second power supply line for transmitting the DC voltage to the pair of input terminals, The electronic device according to claim 1, wherein the short-circuit current detection unit detects the current flowing through a resistor inserted in the second power supply line as the short-circuit current. The electronic device according to claim 1.

4. The electronic device according to claim 1, wherein the short-circuit current detection unit detects the current flowing through a resistor connected to the pair of output terminals as the short-circuit current.

5. The electronic device according to any one of claims 1 to 4, further comprising a stop unit that stops the input of the DC voltage to the pair of input terminals of the insulating power supply circuit when the short circuit is detected.

6. The electronic device according to claim 1, wherein the short-circuit detection unit further detects the short-circuit location.

7. In an electronic device including an insulating power supply circuit having a pair of input terminals to which a DC voltage is input and a pair of output terminals, converting the DC voltage into an output voltage of a predetermined voltage and outputting the output voltage from the output terminals, and one of the pair of input terminals being grounded, a common line connected to one of the pair of output terminals for supplying a reference voltage, an input / output circuit connected to the common line and performing at least one of signal input and signal output with an external device, and a power supply line for supplying power to the input / output circuit and to which a ground fault detection circuit is connected, Detecting a short-circuit current flowing to the ground side via the ground fault detection circuit when the input terminal and the output terminal of the insulating power supply circuit are short-circuited; Detecting a short circuit based on the result of the detection A short circuit detection method including the above.

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