Industrial control equipment and control method for industrial control equipment

Abstract

To provide industrial control equipment that can reduce costs.SOLUTION: Industrial control equipment comprises: a signal generating section that generates control signals; an output control element whose opening and short-circuiting between the two ends is controlled based on a control signal; a current path connected to one of the two ends of the output control element; a measurement section that measures the current value flowing in the direction to one end from the other end of the two ends of the output control element in the current path; a judgment section that determines that an abnormality in the output control element has been detected when the current value measured by the measurement section is equal to or greater than a predetermined value; and a control section that controls the operation of the signal generating section so that the control signal has a pulse width of a predetermined time period based on the electrical characteristics of the output control element.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an industrial control device and a control method for an industrial control device. [Background technology]

[0002] 2. Description of the Related Art Industrial control devices that have a function of cutting off a current when an overcurrent is detected are known.

[0003] In this regard, Patent Document 1 discloses a device in which an overcurrent interruption element and an overcurrent detection circuit are connected in series to a switching element, and when an overcurrent flows through the overcurrent interruption element, the device interrupts the current both by using the overcurrent interruption element and by turning off the switching element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-12923 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technique described in Patent Document 1 requires providing an overcurrent interruption element for each switching element, which poses the problem that it is not possible to reduce the cost or size of the device.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide an industrial control device that can reduce costs. [Means for solving the problem]

[0007] In order to solve the above problems, the industrial control device of the present invention comprises a signal generating unit that generates a control signal, an output control element whose open and short circuits between both ends are controlled based on the control signal, a current path connected to one of the ends of the output control element, a measuring unit that measures a current value flowing in the current path in a direction from the other end of the output control element toward the one end, a judgment unit that judges that an abnormality has been detected in the output control element if the current value measured by the measuring unit is equal to or greater than a predetermined value, and a control unit that controls the operation of the signal generating unit so that the control signal has a pulse width of a predetermined time based on the electrical characteristics of the output control element.

[0008] In addition, the output control elements are provided in plurality, and further include a selection unit that selects one of the plurality of output control elements, the current path is connected to one end of the plurality of output control elements, and the control unit controls the operation of the selection unit so that the selection unit selects each of the output control elements in sequence.

[0009] In addition, the control unit further includes a notification unit that notifies an operator of whether the abnormality has been detected and, if the abnormality is detected, information indicating which of the output control elements the abnormality has been detected in. When the control unit determines that the determination unit has detected the abnormality, it transmits information to the notification unit indicating that the abnormality has been detected in the output control element selected by the selection unit.

[0010] Moreover, the output control element is a transistor, and the electrical characteristic is a maximum rated current at the time of pulse input to the output control element.

[0011] The control unit also has a second operating mode for inspecting the connection state of the output control element and the driving device, which is an operating mode different from a first operating mode for operating a driving device connected to the other end of the output control element, and in the second operating mode, controls the operation of the signal generating unit so that the control signal has a pulse width of a predetermined time that is determined based on the electrical characteristics of the output control element.

[0012] In addition, the control method for an industrial control device of the present invention includes generating a control signal to have a pulse width of a predetermined time based on the electrical characteristics of an output control element, controlling an open circuit and a short circuit between both ends of the output control element based on the control signal, measuring a current value flowing in a direction from the other end to one end in a current path connected to one of the ends of the output control element, and determining that an abnormality has been detected in the output control element if the measured current value is equal to or greater than a predetermined value. Effect of the Invention

[0013] According to the present invention, the industrial control device can reduce costs. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram showing an overall configuration of an industrial control system according to a first embodiment. [Diagram 2] 2 is a timing chart showing transitions of potentials of signals in the industrial control device shown in FIG. 1. [Diagram 3] 2 is an example of a flowchart showing a flow of a series of processes of the industrial control device shown in FIG. 1. [Figure 4] FIG. 11 is a diagram showing the overall configuration of an industrial control system according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention (hereinafter, referred to as a "first embodiment" or a "second embodiment") will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components and steps in each drawing are denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0016] ---First embodiment--- First, the first embodiment will be described.

[0017] <Overall composition> 1 is a diagram showing an overall configuration of an industrial control system 1A according to a first embodiment. As shown in FIG. 1, the industrial control system 1A includes, as its main part, an industrial control device 10A and a drive device 20, for example.

[0018] The industrial control device 10A is, for example, a device for controlling the operation of the drive device 20. The industrial control device 10A is connected to a plurality of loads 21 in the drive device 20 via output terminals O1-On, and controls the conduction state of a current path 104A passing through the output terminals O1-On to operate or stop the operation of each of the loads 21. The industrial control device 10A is also connected to a reference line W_GND via an output terminal Ocm.

[0019] The driving device 20 is, for example, an industrial device such as a robot, a machine tool, or a tester, and operates based on a control command from the industrial control device 10A. The driving device 20 has a main part including, for example, a plurality of loads 21, and output terminals O1-On of the industrial control device 10A are connected to the loads 21 in one-to-one correspondence. In the driving device 20, the loads 21 operate according to the current supplied via the output terminals O1-On connected to the loads 21.

[0020] The load 21 is, for example, a motor, a lamp, or a relay, and operates according to the potential supplied from the power supply VDD and the current flowing through the load 21. A plurality of loads 21 are provided in the driving device 20, one end of which is connected to one of the output terminals O1 to On of the industrial control device 10A, and the other end of which is connected to the positive terminal of the power supply VDD.

[0021] The power supply VDD is, for example, a DC voltage source, and supplies a power supply potential to each load 21. The power supply VDD has a positive terminal connected to the other end of each load 21, and a negative terminal connected to the reference line W_GND.

[0022] Next, a detailed configuration of the industrial control device 10A will be described. The industrial control device 10A includes, as its main part, an output module 100, a control unit 200, a storage unit 300, and a notification unit 400, for example.

[0023] The control unit 200 includes, for example, a CPU and a memory as its main components. The control unit 200 controls the operation of the industrial control device 10A, including the operation of the output module 100 and the notification unit 400, by executing a predetermined program stored in the memory, the storage unit 300, etc.

[0024] The control unit 200 has a first operation mode for operating the drive device 20 and a second operation mode for inspecting the connection state of the output control elements TR1 to TRn and the drive device 20, which is different from the first operation mode, and operates in either the first operation mode or the second operation mode. The control unit 200 transitions to the second operation mode when, for example, the industrial control device 10A is started up, an operator issues a command to transition to the second operation mode, or a predetermined time elapses in the first operation mode. In addition, the control unit 200 transitions to the first operation mode, for example, as soon as the operation in the second operation mode ends.

[0025] In the first operating mode, the control unit 200 controls the open and short states between the emitter terminals and collector terminals of the output control elements TR1 to TRn in accordance with an operating program stored in the memory unit 300, thereby controlling the supply and stop of the supply of current flowing to each load 21, thereby causing the drive device 20 to operate as a robot, a machine tool, a tester, etc.

[0026] In the second operation mode, the control unit 200 sequentially inspects the connection relationship between the output control elements TR1 to TRn and the drive device 20 according to a short-circuit inspection program stored in the storage unit 300. Specifically, the control unit 200 causes the signal generation unit 101 to generate a control signal ST so that the control signal has a pulse width of a predetermined time based on the electrical characteristics of the output control elements TR1 to TRn, and causes the selection unit 102 to output the generated control signal ST. The control unit 200 also controls the operation of the selection unit 102 to select each of the output control elements TR1 to TRn in turn. Furthermore, the control unit 200 receives a signal including a result regarding the presence or absence of detection of an abnormality from the determination unit 106, and when the signal indicates that an abnormality has been detected, transmits information indicating that an abnormality has been detected in the output control element selected by the selection unit 102 to the notification unit 400.

[0027] The storage unit 300 stores an operation program for the control unit 200 to control the industrial control device 10A, a program for short circuit inspection, and information regarding the pulse width of the control signal ST in the short circuit inspection. The pulse width of the control signal ST is, for example, a pulse width determined in a regulation regarding the maximum rated current upon pulse input to the output control elements TR1 to TRn, and is stored in the storage unit 300. Here, the maximum rated current upon pulse input is, for example, the maximum value of a current that can be passed and whose operation is guaranteed when a pulse signal with a determined pulse width is input to the output control elements TR1 to TRn.

[0028] The notification unit 400 is, for example, a display device such as a display, and notifies an operator of the industrial control device 10A of the detection of an abnormality and information indicating which output control element the abnormality has been detected in, which is transmitted from the control unit 200. The notification unit 400 also receives various information related to the control of the industrial control device 10A from the control unit 200, and notifies the operator.

[0029] The output module 100 is a module for controlling current conduction and non-conduction for the load 21 of the driving device 20. The output module 100 is mainly configured to include, for example, a signal generating unit 101, a selecting unit 102, an opening / closing operation unit 103, output control elements TR1 to TRn, a current path 104A, a measuring unit 105, and a determining unit 106.

[0030] The signal generating unit 101 generates a control signal ST under the control of the control unit 200, and transmits the generated control signal ST to the selecting unit 102. The control signal ST is a signal for controlling an open or short state between the emitter terminals and the collector terminals of the output control elements TR1 to TRn connected downstream from the signal generating unit 101 via the selecting unit 102 and the opening and closing operation unit 103. In the second operation mode, the control signal ST is, for example, a pulse signal having a pulse width of a predetermined time.

[0031] The selection unit 102 is, for example, a multiplexer. The selection unit 102 selects one of the multiple output signal lines leading to the output control elements TR1 to TRn via the opening and closing operation unit 103 under the control of the control unit 200, and outputs the control signal ST transmitted from the signal generation unit 101 to the selected one output signal line to the selected one output signal line.

[0032] The switching operation unit 103 opens or shorts the state between the emitter terminal and the collector terminal of one of the output control elements TR1 to TRn connected in the subsequent stage according to the control signal ST transmitted from the signal generating unit 101 via the selecting unit 102. Specifically, for example, when the control signal ST output from the selecting unit 102 is in a high state, the switching operation unit 103 connected to the subsequent stage of the output control element TR1 supplies a current to the base terminal of the output control element TR1 to short the emitter terminal and the collector terminal of the output control element TR1 to make it conductive. On the other hand, when the control signal ST output from the selecting unit 102 is in a low state, the switching operation unit 103 connected to the subsequent stage of the output control element TR1 stops supplying a current to the base terminal of the output control element TR1 to open the emitter terminal and the collector terminal of the output control element TR1 to make it non-conductive.

[0033] The output control elements TR1 to TRn are, for example, NPN-type bipolar transistors. In response to the supply of current to the base terminal, the output control elements TR1 to TRn short-circuit between the emitter terminal and the collector terminal, bringing the emitter terminal and the collector terminal into a conductive state. In response to the stop of the supply of current to the base terminal, the output control elements TR1 to TRn open between the emitter terminal and the collector terminal, bringing the emitter terminal and the collector terminal into a non-conductive state. The output control element TR1 has a base terminal connected to the opening / closing operation unit 103, an emitter terminal connected to the current path 104A, and a collector terminal connected to one of the output terminals O1 to On corresponding thereto.

[0034] In the first embodiment, the output control elements TR1 to TRn are NPN bipolar transistors, but are not limited to this. The output control elements TR1 to TRn may be any elements or circuits that can control opening and shorting between both ends according to a control signal, such as PNP bipolar transistors, MOS transistors, photocouplers, etc.

[0035] The current path 104A is a path that extends from the emitter terminals of the output control elements TR1 to TRn to the output terminal Ocm via a resistive element R1 of the measuring unit 105. A current IO is supplied to the current path 104A from a terminal that is connected to the collector terminal of the output control element selected from the output terminals O1 to On by the selecting unit 102. The current IO supplied to the current path 104A flows to the reference line W_GND via the output terminal Ocm.

[0036] The measuring unit 105 measures the value of a current flowing in the direction from the collector terminals to the emitter terminals of the output control elements TR1 to TRn in the current path 104 A. The measuring unit 105 mainly includes, for example, a resistive element R1 and an amplifier AMP.

[0037] The resistive element R1 is, for example, a shunt resistor for measuring current. The resistive element R1 measures the current flowing through the current path 104A by converting the current flowing through the resistive element R1 into a potential difference according to the electric resistance value of the resistive element R1. One end of the resistive element R1 is connected to the emitter terminals of the output control elements TR1 to TRn and the non-inverting input terminal + of the amplifier AMP, and the other end is connected to the inverting input terminal - of the amplifier AMP and the output terminal Ocm.

[0038] The amplifier AMP is, for example, an operational amplifier. The amplifier AMP amplifies the potential difference across the resistor R1 by a predetermined factor, and transmits a pulse signal having an amplitude of the amplified potential difference to the pulse detection unit 1061 of the determination unit .

[0039] The determination unit 106 determines that an abnormality has been detected in the output control elements TR1 to TRn when the current value measured by the measurement unit 105 is equal to or greater than a predetermined current value. The determination unit 106 is mainly configured to include, for example, a pulse detection unit 1061 and an abnormality detection unit 1062.

[0040] The pulse detection unit 1061 is, for example, a latch circuit having a reset function. The pulse detection unit 1061 receives a pulse signal transmitted from the amplifier AMP, and when the amplitude of the received pulse signal is equal to or greater than a predetermined voltage value, the state of the latch circuit is set to "on", and the signal WNG is output to the abnormality detection unit 1062 so as to include information indicating that an abnormality has been detected. In contrast, when the amplitude of the received pulse signal is less than the predetermined voltage value, the pulse detection unit 1061 maintains the output state. In addition, the pulse detection unit 1061 sets the state of the latch circuit to "off" in accordance with a clear signal CLR transmitted from the abnormality detection unit 1062. The predetermined voltage value is calculated by the control unit 200 in accordance with a predetermined current value stored in the storage unit 300, and is transmitted to the pulse detection unit 1061.

[0041] The abnormality detection unit 1062 checks the state of the output from the pulse detection unit 1061 after a predetermined time has elapsed since the signal generation unit 101 generated a control signal ST having a pulse and output the control signal ST to the selection unit 102. When the signal WNG is output from the pulse detection unit 1061, the abnormality detection unit 1062 determines that an abnormality has been detected in the current path 104A passing through one selected from the output control elements TR1 to TRn, transmits a signal indicating that an abnormality has been detected to the control unit 200, and transmits a clear signal CLR to the pulse detection unit 1061. On the other hand, when the signal WNG is not output from the pulse detection unit 1061, the abnormality detection unit 1062 determines that an abnormality has not been detected in the current path 104A passing through one selected from the output control elements TR1 to TRn, transmits a signal indicating that an abnormality has not been detected to the control unit 200, and transmits a clear signal CLR to the pulse detection unit 1061.

[0042] <Flow of operations> The configuration of the industrial control device 10A has been described above. Next, the transition of the potential of each signal in the industrial control device 10A will be described in detail. Fig. 2 is a timing chart showing the transition of the potential of each signal in the industrial control device 10A shown in Fig. 1. Note that in this example, a case will be described in which the output terminal O2 connected to the collector terminal of the output control element TR2 is short-circuited to a power source or the like instead of the load 21, causing an abnormality in the connection relationship.

[0043] At time t1, the control unit 200 controls the operation of the signal generating unit 101 to generate a control signal ST having a predetermined pulse width. Also, at time t1, the control unit 200 controls the operation of the selecting unit 102 to select the output control element TR1. At time t1, the state of the control signal ST transitions from a low state to a high state in accordance with the control signal ST. Also, the state of the signal g1 transmitted through the output signal line leading to the output control element TR1 transitions from a low state to a high state. At time t1, the current IO flowing through the current path 104A changes from approximately 0 A to a current value Ia less than a predetermined value Ith. At time t1, the state of the signal WNG transmitted from the pulse detecting unit 1061 to the abnormality detecting unit 1062 transitions to a low state.

[0044] At time t2, the state of the control signal ST transitions from a high state to a low state. At time t2, the state of the signal g1 also transitions from a high state to a low state. At time t2, the current IO flowing through the current path 104A changes from a current value Ia less than the predetermined value Ith to approximately 0 A. Between time t1 and time t2, the judgment unit 106 does not detect an abnormality because the current value of the current IO is less than the predetermined value Ith. At time t2, the state of the clear signal CLR transmitted from the abnormality detection unit 1062 to the pulse detection unit 1061 transitions to a low state.

[0045] At time t3, the control unit 200 controls the operation of the selection unit 102 to select the output control element TR2. At time t3, the state of the control signal ST transitions from a low state to a high state. At time t3, the state of the signal g2 transmitted through the output signal line leading to the output control element TR2 transitions from a low state to a high state. At time t3, the current IO flowing through the current path 104A changes from approximately 0 A to a current value Ib equal to or greater than a predetermined value Ith.

[0046] At time t4, the state of the control signal ST transitions from a high state to a low state. The state of the signal g2 also transitions from a high state to a low state. At time t4, the current IO flowing through the current path 104A transitions from a current value Ib equal to or greater than a predetermined value Ith to approximately 0 A. At time t3, the state of the signal WNG transitions from a low state to a high state.

[0047] At time t4, the state of the control signal ST transitions from a high state to a low state. At time t4, the state of the signal g2 also transitions from a high state to a low state. At time t2, the current IO flowing through the current path 104A transitions from a current value Ib equal to or greater than a predetermined value Ith to approximately 0 A.

[0048] At time t40, a predetermined time after time t3, the current value of the current IO is equal to or greater than the predetermined value Ith from time t3 to time t4, so the determination unit 106 detects an abnormality. At time t40, the clear signal CLR transitions from a low state to a high state, and after a certain time has passed, transitions from a high state to a low state. Accordingly, the state of the pulse detection unit 1061 is cleared, and at time t40, the signal WNG transitions from a high state to a low state.

[0049] At time t5, the control unit 200 controls the operation of the selection unit 102 to select the output control element TR3. At time t5, the state of the control signal ST transitions from a low state to a high state. At time t5, the state of the signal g3 transmitted through the output signal line leading to the output control element TR3 transitions from a low state to a high state. At time t5, the current IO flowing through the current path 104A changes from approximately 0 A to a current value Ia that is less than a predetermined value Ith.

[0050] At time t6, the state of the control signal ST transitions from a high state to a low state. The state of the signal g3 also transitions from a high state to a low state. At time t6, the current IO flowing through the current path 104A becomes approximately 0 A from a current value Ia less than a predetermined value Ith. At time t6, the state of the signal WNG is maintained in a low state.

[0051] The transition of the potential of each signal in the industrial control device 10A has been described above. Next, a series of process flows in the industrial control device 10A will be described in detail. Fig. 3 is an example of a flowchart showing a series of process flows in the industrial control device 10A shown in Fig. 1. In Fig. 3, the operation mode of the control unit 200 is the second operation mode.

[0052] (Step SP10) The industrial control device 10A generates a control signal ST having a pulse width of a predetermined time by the control unit 200, and controls the operation of the signal generating unit 101 to transmit the generated control signal ST. Then, the process proceeds to step SP12.

[0053] (Step SP12) The industrial control device 10A controls the operation of the selection unit 102 so as to select one output control element whose connection state has not been inspected in the inspection of the connection state in the second operation mode from among the output control elements TR1 to TRn, by the control unit 200. Then, the process proceeds to the process of step SP14.

[0054] (Step SP14) The industrial control device 10A causes the selected one output control element to be in a conductive state by opening the emitter terminal and the collector terminal of the selected one output control element with the opening / closing operation unit 103. Then, the process proceeds to step SP16.

[0055] (Step SP16) The industrial control device 10A measures the current value of the current IO flowing through the current path 104A by the measurement unit 105. Then, the process proceeds to step SP18.

[0056] (Step SP18) The industrial control device 10A determines whether or not the current value of the current IO flowing through the current path 104A is equal to or greater than a predetermined value Ith by the determination unit 106. If the determination is positive, the process proceeds to step SP20. On the other hand, if the determination is negative, the process proceeds to step SP24.

[0057] (Step SP20) The industrial control device 10A determines that an abnormality in the connection state has been detected in the currently selected output control element by the determining unit 106. Then, the process proceeds to step SP22.

[0058] (Step SP22) The industrial control device 10A causes the abnormality detection unit 1062 to transmit a clear signal CLR to the pulse detection unit 1061, turning off the state of the latch circuit of the pulse detection unit 1061. Furthermore, the industrial control device 10A causes the control unit 200 to store in the storage unit 300 information indicating that an abnormality has been detected in the output control element currently selected by the selection unit 102. Then, the process proceeds to step SP24.

[0059] (Step SP24) The industrial control device 10A determines whether or not the connection state of all of the output control elements TR1 to TRn that are to be inspected in the second operation mode has been inspected by the control unit 200. If the determination is negative, the process returns to step SP12. On the other hand, if the determination is positive, the series of processes shown in FIG. 3 ends.

[0060] <Effects> As described above, in the first embodiment, the industrial control device 10A measures the current IO flowing through the current path 104A and detects the presence or absence of an abnormality in the connection state of the output control elements TR1 to TRn by using a simple configuration including the measurement unit 105 and the determination unit 106. Therefore, the industrial control device 10A can reduce costs.

[0061] Furthermore, even when a plurality of output control elements TR1 to TRn are provided, the industrial control device 10A sequentially detects the presence or absence of an abnormality in the connection state of the output control elements TR1 to TRn by the measurement unit 105 and the determination unit 106. Therefore, the industrial control device 10A can reduce costs.

[0062] Furthermore, the industrial control device 10A notifies the operator of which of the output control elements TR1 to TRn an abnormality in the connection state has been detected, so that the operator of the industrial control device 10A can easily understand the results of the inspection.

[0063] Furthermore, the industrial control device 10A passes the current IO through the current path 104B within a range that the output control elements TR1-TRn can instantaneously withstand, thereby reducing the trouble of replacing fuses that are blown by the current IO. The industrial control device 10A can also prevent the output control elements TR1-TRn from burning out due to the current IO.

[0064] Furthermore, the industrial control device 10A switches between the first operation mode and the second operation mode to inspect the operation or connection state of the drive device 20, and therefore can easily inspect the connection states of the output control elements TR1 to TRn.

[0065] --- Second embodiment --- Next, a second embodiment will be described.

[0066] <Overall composition> Fig. 4 is a diagram showing the overall configuration of an industrial control system 1B according to the second embodiment. As shown in Fig. 4, the industrial control system 1B is mainly configured to include, for example, an industrial control device 10B, a driving device 20, and an inspection module 30. Note that the driving device 20 is similar to that in the first embodiment, and therefore a description thereof will be omitted. Also, the same reference numerals are used for the same configuration as in the first embodiment, and a description thereof will be omitted.

[0067] The industrial control device 10B is configured by excluding the measurement unit 105, the judgment unit 106, and the notification unit 400 from the industrial control device 10A. In the industrial control device 10B, the control unit 200 has a first operation mode and a second operation mode, as in the first embodiment. In the second operation mode, the control unit 200 causes the signal generation unit 101 to generate a control signal ST so as to bring the emitter terminals and the collector terminals of the output control elements TR1 to TRn into a conductive state. In addition, in the second operation mode, the control unit 200 controls the operation of the selection unit 102 so as to select the output control elements TR1 to TRn in order. Note that the industrial control device 10B only excludes the function of notifying the operator of the detection of an abnormality transmitted from the control unit 200 and information indicating which output control element the abnormality has been detected in, from the industrial control device 10A, and may be provided with a function of receiving various information related to the control of the industrial control device 10B from the control unit 200 and notifying the operator.

[0068] The inspection module 30 is a device for inspecting the connection relationship between the output terminals O1-On of the industrial control device 10B and the driving device 20. The inspection module 30 receives a current IO from the output terminal Ocm of the industrial control device 10B and measures the current value of the current IO to determine whether the current value is equal to or greater than a predetermined value, thereby detecting an abnormality in the connection state between any of the output control elements TR1-TRn and the driving device 20. The inspection module 30 outputs the presence or absence of the abnormality as a signal WNG to a notification device such as a lamp, and notifies the operator of the industrial control system 1B. The main part of the inspection module 30 includes, for example, an inspection signal generating circuit 31, a short-circuit control element SW, a resistive element R2, a current detecting circuit 32, and a latch circuit 33. In the second embodiment, the current path 104B is formed so as to extend from the emitter terminal of the output control elements TR1-TRn of the industrial control device 10A to the reference line W_GND via the short-circuit control element SW and the resistive element R2 in the inspection module 30.

[0069] The test signal generating circuit 31 generates a test signal TEST having a pulse width of a predetermined time based on the electrical characteristics of the output control elements TR1 to TRn in response to an input to an input element such as a push button connected to a test terminal. The test signal generating circuit 31 transmits the generated test signal TEST to the short-circuit control element SW.

[0070] The short-circuit control element SW is, for example, a switch element such as a photorelay. The short-circuit control element SW controls the state between both ends to be conductive or non-conductive by controlling the open and short of both ends in response to the test signal TEST transmitted from the inspection signal generating circuit 31. One end of the short-circuit control element SW is connected to the output terminal Ocm of the industrial control device 10B via the input terminal IN, and the other end is connected to one end of the resistor element R2 and the positive terminal of the current detection circuit 32.

[0071] The resistive element R2 is, for example, a shunt resistor for measuring current. The resistive element R2 measures the current flowing through the current path 104B by converting the current flowing through the resistive element R2 into a potential difference according to the electrical resistance value of the resistive element R2. One end of the resistive element R2 is connected to the other end of the short control element SW and the positive terminal of the current detection circuit 32, and the other end is connected to the negative terminal of the current detection circuit 32 and the reference line W_GND.

[0072] The current detection circuit 32 amplifies the potential difference across the resistor element R2 and transmits the amplified signal to the latch circuit 33. The latch circuit 33 determines whether the amplitude of the signal transmitted from the current detection circuit 32 is equal to or greater than a predetermined potential difference. If the determination is positive, the latch circuit 33 determines that the current IO flowing through the current path 104B is equal to or greater than a predetermined current value, and outputs a signal WNG indicating that an abnormality has been detected to an external notification device. The latch circuit 33 also generates a clear signal CLR in response to an input to an input element such as a push button connected to the reset terminal, and turns off the latch state using the clear signal CLR.

[0073] <Effects> In the second embodiment, as described above, the inspection module 30 can detect an abnormality in the connection state of the output control elements TR1 to TRn in the industrial control device 10B even if the industrial control device 10B does not have a circuit or configuration for inspecting the connection state between the output control elements TR1 to TRn and the drive device 20.

[0074] <Modification> The present invention is not limited to the above-described embodiment. In other words, the above-described embodiment may be modified by a person skilled in the art as appropriate, and the modifications may be included within the scope of the present invention as long as they include the characteristics of the present invention. In addition, the elements of the above-described embodiment and the modifications described below may be combined to the extent technically possible, and the combinations of these may be included within the scope of the present invention as long as they include the characteristics of the present invention.

[0075] For example, in the first and second embodiments, the pulse width of the control signal ST and the test signal TEST is determined with respect to the maximum rated current at the time of pulse input in the output control elements TR1 to TRn, but is not limited to this. The pulse width may be determined such that the product of the rated current, determined as the maximum value of the current that can be continuously applied to the output control elements TR1 to TRn, multiplied by a predetermined coefficient and the pulse width is equal to or smaller than a specified value.

[0076] According to this configuration, the industrial control devices 10A and 10B determine the pulse width based on the rated current, which is defined as the current that can be continuously passed through the output control elements TR1 to TRn. Therefore, even when the maximum rated current at the time of pulse input is unknown or when a different pulse width is to be used, an abnormality in the connection state with the drive device 20 can be detected at low cost.

[0077] In the second embodiment, the industrial control system 1B generates the test signal TEST so that the test signal generating circuit 31 in the test module 30 has a predetermined pulse width, but is not limited to this. For example, the control unit 200 of the industrial control device 10B in the industrial control system 1B may generate the control signal ST so that the control signal ST has a predetermined pulse width that is determined in advance according to the electrical characteristics of the output control elements TR1 to TRn in accordance with a short circuit test program. Furthermore, the industrial control system 1B and the test module 30 may generate the test signal TEST so that the short circuit control element SW is brought into a conductive state when there is an input to the test signal generating circuit 31 by an operator, and the short circuit control element SW is brought into a non-conductive state when there is no input.

[0078] According to this configuration, the test module 30 does not require a complex circuit for generating the test signal TEST, and therefore, an abnormality in the connection state between the industrial control device 10B and the drive device 20 can be detected at low cost. [Explanation of symbols]

[0079] 10A... industrial control device, 101... signal generation unit, 102... selection unit, 104A... current path, 105... measurement unit, 106... determination unit, 200... control unit, 400... notification unit, TR1 to TRn... output control elements

Claims

1. A signal generating unit that generates a control signal; an output control element, the open / short circuit between both ends of which is controlled based on the control signal; a current path connected to one end of the output control element; a measurement unit that measures a value of a current flowing in the current path from the other end to the one end of the output control element; a determination unit that determines that an abnormality has been detected in the output control element when the current value measured by the measurement unit is equal to or greater than a predetermined value; a control unit that controls an operation of the signal generating unit so that the control signal has a pulse width of a predetermined time that is determined based on an electrical characteristic of the output control element; An industrial control device comprising:

2. The output control element is provided in plurality, A selection unit for selecting one of the plurality of output control elements, the current path is connected to the one ends of the plurality of output control elements; The control unit controls the operation of the selection unit so that the selection unit selects each of the output control elements in sequence.

2. The industrial control device according to claim 1 .

3. a notification unit that notifies an operator of information indicating whether the abnormality has been detected and, if the abnormality has been detected, regarding which of the output control elements the abnormality has been detected; When the determination unit determines that the abnormality has been detected, the control unit transmits, to the notification unit, information indicating that the abnormality has been detected in the output control element selected by the selection unit.

3. The industrial control device according to claim 2 .

4. the output control element is a transistor, The electrical characteristic is a maximum rated current at the time of pulse input to the output control element.

4. The industrial control device according to claim 1, wherein the control device is a control device for controlling an industrial device.

5. the control unit has a second operation mode for inspecting a connection state of the output control element and the drive device, which is an operation mode different from a first operation mode for operating a drive device connected to the other end of the output control element, and in the second operation mode, controls the operation of the signal generating unit so that the control signal has a pulse width of a predetermined time that is determined based on an electrical characteristic of the output control element.

4. The industrial control device according to claim 1, wherein the control device is a control device for controlling an industrial device.

6. generating a control signal having a pulse width of a predetermined time that is determined based on an electrical characteristic of an output control element; Controlling opening and shorting between both ends of the output control element based on the control signal; measuring a value of a current flowing in a direction from the other end to the one end in a current path connected to the one end of the output control element; determining that an abnormality has been detected in the output control element when the measured current value is equal to or greater than a predetermined value; A control method for an industrial control device comprising:

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