Communication control apparatus

Abstract

Provided is a communication control apparatus capable of maintaining the behavior of a device within the expectations of a worker. A communication control apparatus 13 comprises: signal lines 38, 42 that connect remote devices 14a, 14b, 14c used for management of manufacturing devices 19a, 19b, 19c via a network to the target manufacturing devices 19a, 19b, 19c; and a first breaker 39 and a second breaker 43 that are inserted into the signal lines 38, 42 and physically disconnect the signal lines 38, 42 in response to a physical operation.

Description

Communication control device

[0001] The present invention relates to a communication control device that connects a remote device to a target device via a network.

[0002] Generally, a network is composed of a switching device that distributes communication and nodes such as computers connected to the switching device. As disclosed in Patent Document 1, in the event of communication interruption, for example, in a switching device, communication ports are stopped. A command to stop the communication port is generated. In addition, if a command to stop the connection port is generated in a node, communication is interrupted. The interruption of communication is controlled by software.

[0003] Japanese Unexamined Patent Application Publication No. 2023 - 37695

[0004] In the field of remote control, various devices are connected to a remote device via a network, and the operation of the device is managed using the remote device from a position away from the device installed at the work site. Even if an operator is working around the device, the behavior of the device may be changed from the remote device. The device may exhibit behavior that is unpredictable to the operator. In particular, even if the communication port or connection port is stopped, if a signal leaks from the communication port or connection port to the device due to software defects or unauthorized access, the device may exhibit behavior that the operator cannot anticipate, and may lead to unpredictable serious consequences.

[0005] An object of the present invention is to provide a communication control device that can maintain the behavior of a device within the assumptions of an operator.

[0006] The communication control device according to the present invention includes a signal line that connects a remote device used for managing the device to the target device via a network, and a cutoff mechanism that is inserted into the signal line and physically disconnects the signal line in response to a physical operation.

[0007] According to the disclosed form as described above, since the signal line can be physically disconnected in response to a physical operation as needed from the behavior of the device, the behavior of the device can be maintained within the assumptions of the operator.

[0008] This is a block diagram schematically showing the configuration of the equipment system according to the first embodiment of the present invention. This is a conceptual diagram schematically showing the structure of a first circuit breaker according to one specific example. This is a conceptual diagram schematically showing the structure of a second circuit breaker according to one specific example. This is a block diagram schematically showing the configuration of the equipment system according to the second embodiment of the present invention. This is a block diagram schematically showing the configuration of the equipment system according to the third embodiment of the present invention. This is a block diagram schematically showing the configuration of the equipment system according to the fourth embodiment of the present invention. This is a block diagram schematically showing the configuration of the equipment system according to the fifth embodiment of the present invention.

[0009] One embodiment of the present invention will be described below with reference to the attached drawings.

[0010] <First Embodiment> Figure 1 schematically shows the configuration of an equipment system 11 according to the first embodiment of the present invention. The equipment system 11 includes an OT network (operational technology network) 12 which is constructed in a production facility such as a factory or plant. A communication control device 13 which forms a LAN (local area network) within the factory is connected to the OT network 12. The communication control device 13 is connected to a LAN 16 that forms a Wi-Fi (wireless fidelity) access point 15 accessible from remote devices 14a within the factory, a LAN 17 formed by a wired network connected to an IPC (industrial PC) that functions as a remote device 14b, a data LAN 21 that supplies data to individual manufacturing devices 19a, 19b, and 19c for control purposes, and an engineering LAN 22 used for program rewriting and other purposes for each individual manufacturing device 19a, 19b, and 19c for management purposes.

[0011] Each individual manufacturing device 19a, 19b, and 19c is equipped with a PLC (programmable logic controller) 23a, 23b, and 23c connected to LANs 21 and 22. The PLCs 23a, 23b, and 23c numerically control the manufacturing devices 19a, 19b, and 19c based on their built-in control programs. The manufacturing devices 19a, 19b, and 19c include, for example, NC machine tools, welding robots, painting robots, and others. The communication control device 13 manages the connection and disconnection of remote devices 14a and 14b to each individual PLC 23a, 23b, and 23c. In managing these devices, the communication control device 13 refers to the MAC addresses set on each individual PLC 23a, 23b, and 23c, as well as on the remote devices 14a and 14b.

[0012] For example, the internet 25 is connected to the OT network 12. Remote devices 14c access the OT network 12 via the internet 25. The communication control device 13 connects the remote devices 14c to the individual PLCs 23a, 23b, and 23c via the internet 25. Preferably, a firewall is established between the OT network 12 and the internet 25.

[0013] The communication control device 13 includes a switching circuit 31 that switches the connection of remote devices 14a, 14b, and 14c to the manufacturing devices 19a, 19b, and 19c via a network. The switching circuit 31 is connected to a LAN jack 32 that accepts the plug of a LAN cable used to form LAN 16, a LAN jack 33 that accepts the plug of a LAN cable used to form LAN 17, a LAN jack 34 that accepts the plug of a LAN cable used to form LAN 21, a LAN jack 35 that accepts the plug of a LAN cable used to form LAN 22, and a LAN jack 36 that accepts the plug of a LAN cable used to connect to the OT network 12. The switching circuit 31 establishes signal lines between the individual remote devices 14a, 14b, and 14c and the individual manufacturing devices 19a, 19b, and 19c in accordance with the switching of connections.

[0014] In the communication control device 13, a first circuit breaker 39 is inserted between the switching circuit 31 and the LAN jack 34 in the signal line 38. The first circuit breaker 39 is composed of, for example, a cutoff relay. A lamp 41 that lights up in accordance with the supply of current is connected to the first circuit breaker 39. Here, a normally closed relay is used as the cutoff relay, which establishes a disconnection of the signal line 38 when it receives a control voltage while conducting. As long as the control voltage is not supplied, the continuity of the signal line 38 is maintained. When the signal line 38 is conducting, the lamp 41 lights up. When the signal line 38 is disconnected, the lamp 41 turns off. Note that it is sufficient for the operator to know the continuity / disconnection status of the signal line 38 by whether the lamp 41 is lit or not, so the reverse is also acceptable, such as lighting up the lamp 41 when the signal line 38 is disconnected.

[0015] In the communication control device 13, a second circuit breaker 43 is inserted between the switching circuit 31 and the LAN jack 35 in the signal line 42. The second circuit breaker 43 is composed of, for example, a cutoff relay. A lamp 44 that lights up in accordance with the supply of current is connected to the second circuit breaker 43. Here, a normally open relay is used as the cutoff relay, which establishes continuity of the signal line 42 when it receives a control voltage when the line is broken. The signal line 42 remains broken unless a control voltage is supplied. When the signal line 42 is running, the lamp 44 lights up. When the signal line 42 is broken, the lamp 44 turns off. Note that it is sufficient for the operator to know the continuity / breakage status of the signal line 42 by whether the lamp 44 is lit or not, so the reverse is also acceptable, such as lighting up the lamp 44 when the signal line 42 is broken.

[0016] Logic circuits 45 are connected to the first circuit breaker 39 and the second circuit breaker 43. Based on the operation of the first circuit breaker 39, the logic circuit 45 controls the disconnection and continuity of the signal line 38 between the switching circuit 31 and the LAN jack 34. Similarly, based on the operation of the second circuit breaker 43, the logic circuit 45 controls the disconnection and continuity of the signal line 42 between the switching circuit 31 and the LAN jack 35.

[0017] A physical key switch 46 is connected to the logic circuit 45. The physical key switch 46 includes a key cylinder 47 that rotates in response to the physical operation (rotational drive) of the inserted physical key, and an on / off circuit 48 that generates a specific control signal according to the corner position (reference position) of the key cylinder 47. The key cylinder 47 has a keyhole 49 that accepts the physical key and reflects the rotational operation of the key cylinder 47. The key cylinder 47 is positioned at corner position "0", corner position "1", and corner position "2" in response to the operation of the physical key inserted into the keyhole 49. For positioning, a click sensation should be generated for each of the corner positions "0", "1", and "2". At corner position "0", an off signal is generated for the first circuit breaker 39, and an off signal is generated for the second circuit breaker 43. At corner position "1", an off signal is generated for the first circuit breaker 39, and an on signal is generated for the second circuit breaker 43. At corner position "2", an ON signal is generated for the first circuit breaker 39, and an OFF signal is generated for the second circuit breaker 43.

[0018] The logic circuit 45 includes a timer 51 that measures a predetermined time from the reception of an ON signal. The timer 51 sets a time constraint on the first circuit breaker 39 to prevent disconnection. The first circuit breaker 39 will not remain disconnected for longer than the predetermined time. Similarly, the timer 51 sets a time constraint on the second circuit breaker 43 to prevent continuity. The second circuit breaker 43 will not remain continuity for longer than the predetermined time.

[0019] As shown in Figure 2, one specific example of the first circuit breaker 39 includes a first connector 53 equipped with conductive pins 52a to 52h arranged according to the RJ45 standard, and a second connector 56 equipped with conductive pins 55a to 55h, which are individually connected to the conductive pins 52a to 52h of the first connector 53 by signal lines 54a to 54h and arranged according to the RJ45 standard. The first connector 53 and the second connector 56 may be plugs or jacks. A pair of signal lines 54a and 54b are made of stranded wire. Here, the disconnection mechanism 57 is inserted into the positive (+) side signal lines 54a, 54c, 54e, and 54g of the stranded wire. Figure 2 shows in detail the configuration of the disconnection mechanism 57 provided on signal line 54a, and the detailed configurations of the disconnection mechanisms 57 provided on the other signal lines 54c, 54e, and 54g are omitted. Hereafter, the explanation will focus on the disconnection mechanism 57 provided on signal line 54a.

[0020] The disconnection mechanism 57 has a first terminal 58 connected to the signal line 54a on the first connector 53 side, a second terminal 59 connected to the signal line 54a on the second connector 56 side, and a third terminal 61 separated from both signal lines 54a. A movable piece 63 that is displaced around a rotation axis (an axis extending towards the front and back of the page in Figure 2) 62 is positioned between the second terminal 59 and the third terminal 61. The movable piece 63 is connected to the first terminal 58 by a conductor 64. The movable piece 63 is fixed to a drive body 65 that is rotatable around the rotation axis 62 (rotatable clockwise and counterclockwise in Figure 2). In this invention, the drive unit 65 is configured to rotate freely around the pivot point in response to an external force. However, the present invention is not limited to this configuration. The drive unit 65 may also be configured to tilt freely around the pivot point in response to an external force, or to be configured to bend elastically around the pivot point without breaking in response to an external force.

[0021] The drive unit 65 presses the movable piece 63 against the second terminal 59 through the action of the elastic member 66. The elastic member 66 is, for example, a helical spring, and exerts a driving force that drives the movable piece 63 toward the second terminal 59 around the rotation axis 62 by its elastic force. A solenoid 67 is connected to the drive unit 65. The solenoid 67 generates an electromagnetic force in response to the supply of current. The electromagnetic force exerts a driving force that drives the movable piece 63 toward the third terminal 61 around the rotation axis 62. Since the electromagnetic force exceeds the elastic force of the elastic member 66, the drive unit 65 presses the movable piece 63 against the third terminal 61 in response to the action of the solenoid 67. Current is supplied to the solenoid 67 from the logic circuit 45. Unless a control voltage is supplied from the logic circuit 45, the disconnection mechanism 57 maintains continuity in the signal lines 54a, 54c, 54e, and 54g. When a control voltage is supplied from the logic circuit 45, the disconnection mechanism 57 disconnects the signal lines 54a, 54c, 54e, and 54g.

[0022] As shown in Figure 3, the second circuit breaker 43 is configured similarly to the first circuit breaker 39. However, in the disconnection mechanism 57 of the second circuit breaker 43, the third terminal 61 is connected to the signal lines 54a, 54c, 54e, and 54g on the second connector 56 side, while the second terminal 59 is disconnected from all of the signal lines 54a, 54c, 54e, and 54g. Therefore, unless a control voltage is supplied from the logic circuit 45, the disconnection mechanism 57 of the second circuit breaker 43 maintains the disconnection of the signal lines 54a, 54c, 54e, and 54g. When a control voltage is supplied from the logic circuit 45, the disconnection mechanism 57 makes the signal lines 54a, 54c, 54e, and 54g conductive.

[0023] Next, the operation of the communication control device 13 will be explained. When the key cylinder 47 of the physical key switch 46 is set to corner position "0", the on / off circuit 48 supplies a control signal to the logic circuit 45. In response to the supply of the control signal, the logic circuit 45 generates an off signal for the first circuit breaker 39 and an off signal for the second circuit breaker 42.

[0024] No electromagnetic force is generated in the solenoid 67 of the first circuit breaker 39. The drive unit 65 presses the movable piece 63 against the second terminal 59 using the elastic force of the elastic member 66. The first circuit breaker 39 establishes continuity in the signal lines 54a, 54c, 54e, and 54g. Remote devices 14a, 14b, and 14c are connected to PLCs 23a, 23b, and 23c via networks 16, 17, and 21. PLCs 23a, 23b, and 23c control the operation of manufacturing equipment 19a, 19b, and 19c based on the operation of the remote devices 14a, 14b, and 14c. When continuity is established, the lamp 41 in the communication control device 13 lights up.

[0025] No electromagnetic force is generated in the solenoid 67 of the second circuit breaker 43. The drive unit 65 presses the movable piece 63 against the second terminal 59 using the elastic force of the elastic member 66. The second circuit breaker 43 establishes a disconnection in the signal lines 54a, 54c, 54e, and 54g. The remote devices 14a, 14b, and 14c are disconnected from the PLCs 23a, 23b, and 23c via the networks 16, 17, and 22. The PLCs 23a, 23b, and 23c are disconnected from, for example, engineering tools installed in the remote devices 14a, 14b, and 14c. When the lines are disconnected, the communication control device 13 maintains the off state of the lamp 44.

[0026] When the control programs introduced into PLCs 23a, 23b, and 23c are changed, the remote devices 14a, 14b, and 14c incorporate, for example, engineering tools. The operators of the remote devices 14a, 14b, and 14c communicate their intention to change to the operators of the manufacturing equipment 19a, 19b, and 19c. The operators insert a physical key into the physical key switch 46 to set the key cylinder 47 to corner position "1". When the key cylinder 47 is set to corner position "1", the on / off circuit 48 supplies a control signal to the logic circuit 45. In response to the supply of the control signal, the logic circuit 45 generates an off signal for the first circuit breaker 39 and an on signal for the second circuit breaker 42.

[0027] No electromagnetic force is generated in the solenoid 67 of the first circuit breaker 39. The drive unit 65 presses the movable piece 63 against the second terminal 59 using the elastic force of the elastic member 66. The first circuit breaker 39 establishes continuity in the signal lines 54a, 54c, 54e, and 54g. Remote devices 14a, 14b, and 14c are connected to PLCs 23a, 23b, and 23c via networks 16, 17, and 21. PLCs 23a, 23b, and 23c control the operation of manufacturing equipment 19a, 19b, and 19c based on the operation of the remote devices 14a, 14b, and 14c. When continuity is established, the lamp 41 in the communication control device 13 lights up.

[0028] An electromagnetic force is generated in the solenoid 67 of the second circuit breaker 43. The drive unit 65 presses the movable piece 63 against the third terminal 61 against the elastic force of the elastic member 66. The second circuit breaker 43 establishes continuity in the signal lines 54a, 54c, 54e, and 54g. Remote devices 14a, 14b, and 14c are connected to PLCs 23a, 23b, and 23c via networks 16, 17, and 22. Engineering tools installed in remote devices 14a, 14b, and 14c are connected to PLCs 23a, 23b, and 23c. Based on the operation of the engineering tools, the control programs in PLCs 23a, 23b, and 23c are modified. When continuity is established, the lamp 44 in the communication control device 13 lights up.

[0029] Here, the timer 51 sets a time constraint for the second circuit breaker 43. The timer 51 measures the elapsed time since the second circuit breaker 43 became conductive. When the preset time has elapsed, the timer 51 terminates the conductivity of the signal lines 54a, 54c, 54e, and 54g. The logic circuit 45 stops supplying power to the solenoid 67. The signal lines 54a, 54c, 54e, and 54g return to an open state. In this way, it is prevented that the conductivity of the signal lines 54a, 54c, 54e, and 54g is unintentionally maintained.

[0030] The operation of the manufacturing equipment 19a, 19b, and 19c is controlled via LAN 21. Control is limited. Since the first circuit breaker 39 uses a normally closed relay, power supply to the solenoid 67 is not required when the signal line 38 is open. Power is supplied to the solenoid 67 only when control is required to be stopped. Power consumption is minimized. On the other hand, the management of the manufacturing equipment 19a, 19b, and 19c is carried out via LAN 22. Management is limited. The signal line 42 only needs to be open when necessary. Since the second circuit breaker 43 uses a normally open relay, power supply to the solenoid 67 is not required when the signal line 42 is open. Power is supplied to the solenoid 67 only when management is required. Power consumption is minimized.

[0031] In the disconnection mechanism 57, the coil of the solenoid 67 heats up and deteriorates depending on the time the excitation of the solenoid 67 is maintained. Therefore, if the excitation of the solenoid 67 is turned off under normal circumstances, the deterioration of the coil is prevented. The lifespan of the first circuit breaker 39 and the second circuit breaker 43 is extended.

[0032] When the key cylinder 47 of the physical key switch 46 is set to corner position "2", the on / off circuit 48 supplies a control signal to the logic circuit 45. In response to the supply of the control signal, the logic circuit 45 generates an ON signal for the first circuit breaker 39 and an OFF signal for the second circuit breaker 42. Note that transistor circuits may be used instead of the disconnection mechanism 57 for the first circuit breaker 39 and the second circuit breaker 43. However, since the signal line itself is not structurally separated when disconnected in a transistor circuit, a method for reliably establishing insulation when disconnected must be considered.

[0033] An electromagnetic force is generated in the solenoid 67 of the first circuit breaker 39. The drive unit 65 presses the movable piece 63 against the third terminal 61 against the elastic force of the elastic member 66. The first circuit breaker 39 establishes a disconnection in the signal lines 54a, 54c, 54e, and 54g. The remote devices 14a, 14b, and 14c are disconnected from the PLCs 23a, 23b, and 23c via the networks 16, 17, and 21. The operation of the manufacturing devices 19a, 19b, and 19c is stopped. The lamp 41 in the communication control device 13 is turned off.

[0034] No electromagnetic force is generated in the solenoid 67 of the second circuit breaker 43. The drive unit 65 presses the movable piece 63 against the second terminal 59 through the action of the elastic member 66. The second circuit breaker 43 establishes a disconnection in the signal lines 54a, 54c, 54e, and 54g. The remote devices 14a, 14b, and 14c are disconnected from the PLCs 23a, 23b, and 23c via the networks 16, 17, and 22. The PLCs 23a, 23b, and 23c are disconnected from, for example, engineering tools installed in the remote devices 14a, 14b, and 14c. The communication control device 13 maintains the off state of the lamp 44.

[0035] In the communication control device 13, signal lines 38 and 42 are disconnected in response to physical operation by the worker. Manufacturing equipment 19a, 19b, and 19c are disconnected from the control of remote devices 14a, 14b, and 14c. Operation of remote devices 14a, 14b, and 14c does not affect the behavior of manufacturing equipment 19a, 19b, and 19c. The behavior of manufacturing equipment 19a, 19b, and 19c is maintained within the range expected by the worker. Unexpected behavior is prevented, allowing workers to safely work around manufacturing equipment 19a, 19b, and 19c. Because signal lines 38 and 42 are physically disconnected, the behavior of manufacturing equipment 19a, 19b, and 19c is maintained without being affected by software malfunctions or unauthorized access.

[0036] The communication control device 13 according to this embodiment includes a physical key switch 46 that switches the control of the logic circuit 45 in response to the rotational movement of the key cylinder 47 caused by the physical operation of the inserted physical key. The rotational movement of the key cylinder 47 requires the operator to physically operate the physical key. In response to the physical operation of the physical key, the open and closed states of the signal lines 38 and 42 are switched. The physical operation guarantees the open state of the signal lines 38 and 42. A guaranteed open state provides the operator with a sense of security regarding safety. The operator's anxiety is reliably eliminated.

[0037] In this embodiment, the physical key switch 46 has a keyhole 49 that reflects the rotational movement of the key cylinder 47 and identifies open circuits and continuities according to the angle. The keyhole 49 is positioned at corner position "0", corner position "1", or corner position "2". The keyhole 49 visually indicates whether the signal lines 38 and 42 are open or continuity. The operator can easily and reliably confirm whether the signal lines 38 and 42 are open or continuity based on the angle of the keyhole 49.

[0038] <Second Embodiment> Figure 4 schematically shows the configuration of the equipment system 11a according to the second embodiment of the present invention. The communication control device 13a includes a microcontroller unit (MCU) 71 connected to a switching circuit 31. The switching circuit 31 connects remote devices 14a, 14b, and 14c to the MCU 71. The MCU 71 is connected, for example, to a logic circuit 45 and receives signals from the logic circuit 45 that specify the state of the disconnection mechanisms 57 of the first circuit breaker 39 and the second circuit breaker 43, and signals that specify the state of the timer 51. The MCU 71 notifies the remote devices 14a, 14b, and 14c of the state of the disconnection mechanisms 57 and the state of the timer 51. Similarly, the MCU 71 is connected to a physical key switch 46 and receives signals from the physical key switch 46 that specify the angle of the keyhole 49. The MCU 71 notifies the remote devices 14a, 14b, and 14c of the angle of the keyhole 49 and the continuity or disconnection of the signal lines 38 and 42. In addition, the MCU 71 may be connected to the on / off circuit 48 of the physical key switch 46 to constitute a virtual key switch. The MCU 71 controls the continuity or disconnection of the signal lines 38 and 42 in response to the operation of the remote devices 14a, 14b, and 14c. The other configurations are the same as those of the first embodiment described above.

[0039] <Third Embodiment> Figure 5 schematically shows the configuration of the equipment system 11b according to the third embodiment of the present invention. The communication control device 13b includes an on / off interface circuit 72 connected to the on / off circuit 48 of the physical key switch 46. PLCs 23a, 23b, and 23c are connected to the on / off interface circuit 72 via other networks such as a LAN or WAN (Wide Area Network). PLCs 23a, 23b, and 23c supply on / off signals to the on / off circuit 48 via the network. The on / off circuit 48 controls the operation of the first circuit breaker 39 and the second circuit breaker 43 (conduction and interruption of signal lines 38 and 42) based on the supplied on / off signals. In addition, the on / off circuit 48 may notify the PLCs 23a, 23b, and 23c of the conduction or disconnection of signal lines 38 and 42 via the network. As a result, the PLCs 23a, 23b, and 23c can be notified via the on / off interface circuit 72 that remote disconnection has occurred via the physical key switch 46 or the MCU 71. Thus, the PLCs 23a, 23b, and 23c are also effective in that they can understand the situation when communication is interrupted. The other configurations are the same as those of the second embodiment described above.

[0040] In the equipment system 11b shown in Figure 5, the on / off interface circuit 72 is connected to manufacturing equipment 19a, 19b, and 19c equipped with PLCs 23a, 23b, and 23c, but the present invention is not limited to this configuration. For example, the on / off interface circuit 72 may be connected to other equipment such as a computer operated by an operator handling the manufacturing equipment 19a, 19b, and 19c. This allows other equipment to supply on / off signals to the on / off circuit 48 via a network and control the operation of the first circuit breaker 39 and the second circuit breaker 43 based on these on / off signals. In this case as well, the on / off circuit 48 may notify other equipment of the continuity or disconnection of the signal lines 38 and 42 via a network.

[0041] <Fourth Embodiment> Figure 6 schematically shows the configuration of the equipment system 11c according to the fourth embodiment of the present invention. The communication control device 13c includes a microcontroller unit (MCU) 74 connected to a signal line branched from the signal line 38 by an L2 switch 73. The L2 switch 73 is installed on the signal line 38 between the first circuit breaker 39 and the LAN jack 34. The L2 switch 73 connects the MCU 74 to the PLCs 23a, 23b, and 23c. The MCU 74 controls the continuity and disconnection of the signal lines 38 and 42 by the first circuit breaker 39 and the second circuit breaker 43 in accordance with the control signals supplied from the PLCs 23a, 23b, and 23c. In addition, the continuity or disconnection of the signal lines 38 and 42 may be notified from the MCU 74 to the PLCs 23a, 23b, and 23c via the LAN 21. The other configurations are the same as those of the third embodiment described above.

[0042] <Fifth Embodiment> Figure 7 schematically shows the configuration of the equipment system 11d according to the fifth embodiment of the present invention. The communication control device 13d includes, in addition to that of the fourth embodiment, a first on / off interface circuit 76 connected to the MCU 71 and a second on / off interface circuit 78 connected to the MCU 74. The first on / off interface circuit 76 connects the MCU 71 to, for example, the OT network 12 or LANs 16 and 17 (connection lines are omitted in Figure 7). The first on / off interface circuit 76 enables the connection between the remote devices 14a, 14b, and 14c and the MCU 71. The MCU 71 notifies the remote devices 14a, 14b, and 14c of the state of the disconnection mechanism 57, the state of the timer 51, the angle of the keyhole 49, and the continuity or disconnection of the signal lines 38 and 42. The MCU 71 controls the continuity or disconnection of the signal lines 38 and 42 according to the operation of the remote devices 14a, 14b, and 14c. The second on / off interface circuit 78 connects, for example, the MCU 74 to LANs 21 and 22 (connection lines are omitted in Figure 7). The MCU 74 controls the continuity and disconnection of signal lines 38 and 42 by the first circuit breaker 39 and the second circuit breaker 43 in response to control signals supplied from PLCs 23a, 23b, and 23c. The continuity or disconnection of signal lines 38 and 42 is notified from the MCU 74 to PLCs 23a, 23b, and 23c via LAN 21.

[0043] In the communication control device 13d, the remote devices 14a, 14b, and 14c are connected to the manufacturing devices 19a, 19b, and 19c via the first on-off interface circuit 76, MCU 71, logic circuit 45, MCU 74, and second on-off interface circuit 78. Thereby, even when the signal lines 38 and 42 are cut off by the first cutoff device 39 and the second cutoff device 43, information exchange is realized between the remote devices 14a, 14b, 14c and the PLCs 23a, 23b, 23c.

[0044] <Other Embodiments> In each of the above-described embodiments, the case where manufacturing devices 19a, 19b, and 19c including NC machine tools, welding robots, painting robots, etc. are applied as devices has been described. However, the present invention is not limited to this. For example, as other devices, power generation devices provided in power generation facilities such as thermal power plants and hydroelectric power plants, conveying devices for conveying conveyed objects, disaster prevention devices including building disaster prevention alarms, building fire extinguishers, sprinklers, etc., imaging devices, audio devices, and various other devices may be applied.

[0045] Further, as a communication control device according to another embodiment, for example, a configuration in which the on-off interface circuit 72 of the third embodiment is provided in the communication control device 13 of the first embodiment described above, or a configuration in which the MCU 74 of the fourth embodiment is provided in the communication control device 13 of the first embodiment described above, etc., a communication control device in which the configurations of the first to fifth embodiments described above are appropriately combined may be used.

[0046] 13 Communication control device 16, 17 Network (LAN) 19a, 19b, 19c Manufacturing device (device)

Claims

1. A communication control device comprising: a signal line for connecting a remote device used for managing the target device via a network; and a circuit breaker inserted into the signal line to physically disconnect the signal line in response to a physical operation.

2. The communication control device according to claim 1, comprising: a logic circuit connected to the circuit breaker for controlling the disconnection and continuity of the signal line; and a physical key switch for switching the control of the logic circuit in accordance with the rotational movement of the key cylinder caused by the physical operation of the inserted physical key.

3. The communication control device according to claim 2, wherein the circuit breaker is connected to the logic circuit and has a normally closed relay that, when it receives a control voltage during conduction, establishes the disconnection of the signal line.

4. The communication control device according to claim 3, further comprising a timer connected to the physical key switch for setting a time constraint on the disconnection.

5. The communication control device according to claim 2, wherein the circuit breaker is connected to the logic circuit and has a normally open relay that, when it receives a control voltage in the event of a circuit break, establishes continuity in the signal line.

6. The communication control device according to claim 5, further comprising a timer connected to the physical key switch for setting a time constraint on the conduction.

7. The communication control device according to claim 2, wherein the physical key switch has a keyhole that reflects the rotational movement and identifies the disconnection and continuity according to the angle.

8. The communication control device according to claim 2, further comprising a microcontroller unit connected to the logic circuit and generating a signal to notify the remote device of the disconnection or continuity.

9. The communication control device according to claim 8, wherein the microcontroller unit controls the disconnection or continuity in response to the operation of the remote device.

10. The communication control device according to claim 2, further comprising an on / off interface circuit connected to the device and supplying an on / off signal to the logic circuit for controlling the operation of the circuit breaker.

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