Communication isolator for network security and communication isolation method

Abstract

According to the embodiments of the present disclosure, a communication isolator in network communication with an external controller and a central controller is disclosed, the communication isolator comprising: a first communication device receiving a first communication signal corresponding to at least one first signal from the external controller among pressure value, temperature value, running state and water level value, decoding the first communication signal and obtaining first data, and generating a second signal corresponding to the first data using a pre-stored lookup table; and a second communication device receiving the second signal from the first communication device, converting the second signal into second data using the lookup table, encoding the second data into a second communication signal, and transmitting the second communication signal to the central controller.

Description

Technical Field

[0001] This disclosure relates to a communication isolator and communication isolation method for network security, and more specifically, it is characterized by protecting a secure area from a controlled area, and physically protecting important systems within the secure area even if sabotage occurs within the secure area. Background Technology

[0002] Cybersecurity is becoming a hot topic in industry and national security facilities. Therefore, it is essential to be vigilant against damage to critical internal systems caused by unauthorized personnel intruding from unsecured areas into secure areas, or by cyberattacks.

[0003] To monitor and protect against intrusions from controlled areas to secure areas, methods such as installing software firewalls, alerting operators when abnormal traffic is detected, or physically installing unidirectional diodes to enable one-way signal transmission, i.e., sending signals only from the secure area to the controlled area.

[0004] However, these methods cannot receive feedback signals related to whether the network is functioning properly, which may reduce the reliability of the network and signals. Summary of the Invention

[0005] The purpose of this disclosure is to physically isolate the communication between a control system installed in an industrial field and other controllers installed externally, thereby ensuring the operational integrity of the control system installed in the industrial field.

[0006] Furthermore, as is commonly used, firewalls using data diodes provide one-way communication. In contrast, the purpose of this invention is to minimize the damage caused by viruses and the like while providing two-way communication.

[0007] Furthermore, the present invention aims to provide a function for protecting data transmission between a central controller and an external controller.

[0008] Furthermore, the purpose of this invention is to convert digital and analog signals into electrical signals and provide bidirectional communication.

[0009] Furthermore, the purpose of this invention is to transmit and receive sound signals without interfering with two-way communication.

[0010] According to an embodiment of this disclosure, a communication isolator for network communication with a first control system and a second control system may include: a first communication device that receives a first communication signal corresponding to a first signal output from the first control system, decodes the first communication signal to obtain first data, and generates a second signal corresponding to the first data using a pre-stored lookup table; and a second communication device that receives the second signal from the first communication device, converts the second signal into second data using the lookup table, encodes the second data into a second communication signal, and transmits the second communication signal to the second control system.

[0011] According to an embodiment of this disclosure, the second communication device receives a third communication signal corresponding to a first instruction signal from the second control system, decodes the third communication signal and converts it into third data, generates a third signal corresponding to the third data using the lookup table, and transmits the third signal to the first communication device. The first communication device converts the third signal into a fourth communication signal and transmits it to the first control system. In the first control system, an instruction signal corresponding to the fourth communication signal can be generated.

[0012] The first communication device and the second communication device can be connected by a hard wire to send and receive signals.

[0013] The output of the first signal may correspond to a measurement value or control signal corresponding to the first signal.

[0014] The first communication device can be configured to not generate the second signal when there is no value corresponding to the first data in the lookup table.

[0015] The first or second communication device may be configured as firmware.

[0016] According to the communication isolation method of this disclosure, a communication isolator for network communication with a first control system and a second control system may include: a first communication device of the communication isolator receiving a first communication signal corresponding to a first signal output to the first control system; the first communication device decoding the first communication signal and obtaining first data; the first communication device generating a second signal corresponding to the first data using a pre-stored lookup table; a second communication device of the communication isolator receiving the second signal from the first communication device; the second communication device using the lookup table to convert the second signal into second data and encoding the second data into a second communication signal; and the second communication device transmitting the second communication signal to the second control system.

[0017] According to an embodiment of this disclosure, the method may further include: the second communication device receiving a third communication signal corresponding to a first instruction signal from the second control system; the second communication device decoding the third communication signal and converting it into third data, and using the lookup table to generate a third signal corresponding to the third data, and transmitting the third signal to the first communication device; the first communication device converting the third signal into a fourth communication signal and transmitting it to the first control system, and in the external controller, an instruction signal corresponding to the fourth communication signal may be generated.

[0018] The first communication device and the second communication device can be connected by a hard wire to send and receive signals.

[0019] The output of the first signal may correspond to a measurement value or control signal corresponding to the first signal.

[0020] According to an embodiment of this disclosure, the first communication device can be configured to not generate the second signal when there is no value corresponding to the first data in the lookup table.

[0021] The computer program according to embodiments of the present invention can be stored in a medium to allow a computer to run any of the methods according to embodiments of the present invention.

[0022] In addition, another method for implementing the present invention, another system, and a computer-readable recording medium for recording a computer program for running the method are further provided.

[0023] Other aspects, features, and advantages beyond the foregoing will become more apparent from the following drawings, claims, and detailed description of the invention. Attached Figure Description

[0024] Figure 1 This is a diagram of the existing central controller and lower-level controllers.

[0025] Figure 2 This is a block diagram of a communication isolator according to an embodiment of the present invention.

[0026] Figure 3 This is a diagram used to describe the process of digital input signals from the first control system being transmitted to the second control system through a communication isolator.

[0027] Figure 4 This is a diagram used to describe the process of digital signals from the second control system being transmitted to the first control system through a communication isolator.

[0028] Figure 5 It is a diagram used to describe the process of sending and receiving analog input signals through a communication isolator.

[0029] Figure 6 This is a diagram used to describe the process of analog output signals being transmitted from the second control system to the first control system through a communication isolator.

[0030] Figure 7 This is a flowchart of a communication isolation method according to an embodiment of the present invention. Detailed Implementation

[0031] In the following, the structure and function of the invention will be described in detail with reference to the embodiments of the invention shown in the accompanying drawings.

[0032] Because this invention allows for various modifications and numerous embodiments, specific embodiments will be shown in the accompanying drawings and described in detail in the specification. The effects and features of the invention, as well as the methods for achieving these effects and features, will become more apparent with reference to the embodiments described in detail below and the accompanying drawings. However, the invention is not limited to the embodiments disclosed below, but can be implemented in various forms.

[0033] In the following description, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, the same reference numerals will be assigned to the same or corresponding constituent elements, and repeated descriptions thereof will be omitted.

[0034] In the following embodiments, the terms "first," "second," etc., are used to distinguish one constituent element from other constituent elements, rather than having a limiting meaning.

[0035] In the following embodiments, singular expressions include plural expressions, unless the context clearly indicates otherwise.

[0036] In the following embodiments, the terms "comprising" or "having" mean that the features or constituent elements described in this specification are present, and do not preclude the possibility of adding at least one other feature or constituent element.

[0037] In the accompanying drawings, the dimensions of the constituent elements may be enlarged or reduced for ease of illustration. For example, the dimensions and thicknesses of each component shown in the drawings are arbitrarily illustrated for ease of explanation, and therefore the invention is not necessarily limited to those shown.

[0038] Where certain embodiments can be implemented differently, a particular process sequence may be performed differently than the described sequence. For example, two processes described consecutively may actually be performed simultaneously, or may be performed in the reverse order of the described sequence.

[0039] The communication isolator according to embodiments of this disclosure is a device for protecting a secure area from a controlled area (non-secure area), and when sabotage (cyberattack) occurs within the secure area, it can protect critical systems in the secure area by selectively shielding the generated signals physically. The communication isolator according to embodiments of this disclosure can prevent the spread and damage of cyberattacks and network systems because communication other than designated signals is impossible.

[0040] Figure 1 This is a diagram of a traditional central controller and its subordinate controllers.

[0041] Automation systems installed in factories and other similar locations may include a central controller and a plurality of subordinate controllers. The central controller can exchange information with and control the plurality of subordinate controllers through communication, and can also monitor the plurality of subordinate controllers. The central controller is connected to the plurality of subordinate controllers and can exchange information through communication with them.

[0042] The central controller can send and receive data through communication with multiple lower-level controllers, and can control and monitor these lower-level controllers. The central controller can also connect to external controllers. Furthermore, external controllers can transmit control and monitoring signals from field instruments and equipment to the central controller. In this case, due to reasons such as system purpose, distance limitations, system independence, and limitations on expansion, multiple lower-level controllers may need to be added.

[0043] External controllers and / or multiple lower-level controllers connected to the central controller can exchange control signals with each other via communication. When continuously sending and receiving control signals between external controllers and / or multiple lower-level controllers connected to the central controller, control signals from viruses and network attacks can also be exchanged. In this situation, when the central controller receives control signals infected by viruses and / or control signals from network attacks, it may become infected by viruses and / or attacked, thus compromising communication integrity.

[0044] Furthermore, external controllers or subordinate controllers connected to the central controller of the automation system can exchange their own control information via communication. More specifically, the central controller can transmit its control information to external controllers or subordinate controllers. In this case, if the control information is transmitted to an external controller or subordinate controller that is under attack by a virus and / or network attack, the control information may be exposed to the outside world through the external controller or subordinate controller.

[0045] Furthermore, if an unauthorized person infiltrates the communication network into the automated system, the central controller, external controllers, and subordinate controllers may fall into their hands. If these controllers are compromised, critical information regarding them may be exposed to unauthorized individuals. To protect automated systems from these threats, programs such as firewalls can be used. However, while firewalls can prevent external intrusions, they only address the aftermath of an attack.

[0046] After incidents such as malicious code, virus infection, and network attacks occur on lower-level controllers or external controllers connected to the central controller, the damage that has already occurred cannot be recovered. To solve these problems, the communication isolator 100 according to an embodiment of this disclosure is designed to exchange only predefined control information and control signals, and to prevent the exchange of undefined control information and control signals by isolating them, thereby enabling it to cope with attacks such as network attacks.

[0047] Figure 2 This is a block diagram of a communication isolator 100 according to an embodiment of the present invention.

[0048] The communication isolator 100 can be implemented to connect the central controller and lower-level controllers, or the central controller and external controllers, using only digital signals (DI, DO) or analog signals (AI, AO). The communication isolator 100 can be implemented in hardware or software. The communication isolator 100 can isolate the network between the central controller and lower-level controllers, as well as the network between the central controller and external controllers. Figure 2 The first control system 11 can be an external controller or a lower-level controller, and the second control system 12 can be a central controller, but is not limited to this, and can be various control systems.

[0049] Therefore, the communication isolator 100 can ensure the integrity and reliability of information for the central controller. Through the communication isolator 100, it can fundamentally prevent virus intrusion, network attacks, and hacker attacks from existing lower-level controllers, external controllers, and external computers from reaching the central controller. While blocking virus intrusion, network attacks, and hacker attacks, the communication isolator 100 can also enable bidirectional communication between the central controller and lower-level controllers, as well as between the central controller and external controller A.

[0050] The communication isolator 100 according to embodiments of this disclosure can be replaced with an information communication monitoring device. In another embodiment, the communication isolator 100 can be connected between a computer in a secure area and an internal converter in a controlled area, but is not limited thereto. The computer in the secure area can be... Figure 2The second control system may be the first control system, but is not limited to the internal converter of the controlled area.

[0051] The computers in the secure area and the internal converters in the controlled area are connected via communication lines, allowing signals to be pre-selected from the controlled area as communication targets.

[0052] The computers in the secure area and the internal converters in the controlled area can exchange digital and analog signals.

[0053] An internal converter within the controlled area can generate digital (0 to 5 V) or analog (4 to 20 mA) signals as output signals. These output signals can be transmitted via a communication isolator 100. The communication isolator 100 can be implemented such that communication between the secure area system and the controlled area system is prohibited for any signals other than pre-specified digital (0 to 5 V) or analog (4 to 20 mA) signals in the output signals. The communication isolator 100 can isolate signals other than pre-specified digital (0 to 5 V) or analog (4 to 20 mA) signals so that they cannot be sent or received between the secure area system and the controlled area system. The digital (0 to 5 V) or analog (4 to 20 mA) signals are merely an example; communicable signals can be defined by various other standards. Here, the pre-specified digital or analog signals can be specified as voltage or current values, but are not limited to these, and can be specified by various standards. Depending on each receiving device, the digital or analog signals can be specified as different voltage or current values.

[0054] The first control system 11, configured in a controlled area or external controller, may include a first communication module 1a, a central processing unit (CPU) module 2a, a first power supply module 3a, a second power supply module 4a, a second communication module 5a, a digital input module 6a, a digital output module 7a, an analog input module 8a, and an analog output module 9a. The second control system 12 may include a first communication module 1b, a CPU module 2b, a first power supply module 3b, a second power supply module 4b, a second communication module 5b, a digital input module 6b, a digital output module 7b, an analog input module 8b, and an analog output module 9b.

[0055] The first communication module 1a of the first control system 11 performs the function of transmitting signals to the second control system or external devices, and the second communication module 5a can perform the function of communicating with at least one of the internal digital input module 6a, digital output module 7a, analog input module 8a and analog output module 9a.

[0056] The first communication module 1b of the second control system 12 performs the function of transmitting signals to the first control system or external devices, and the second communication module 5b can perform the function of communicating with at least one of the internal digital input module 6b, digital output module 7b, analog input module 8b and analog output module 9b.

[0057] Figure 2 This is a block diagram of a communication isolator according to an embodiment of the present invention.

[0058] The communication isolator 100 may include a first communication device 110 and a second communication device 120. The first communication device 110 and the second communication device 120 can be connected via wired and wireless networks or wires, and can be implemented within a single chipset. Alternatively, the first communication device 110 and the second communication device 120 can be implemented in separate chipsets. The communication isolator 100 can operate via a communication cable connected to a networked control system. Communication signals and / or data transmitted and received between control systems are transmitted via the communication isolator 100. The communication signals and / or data between control systems may have a pre-defined data format.

[0059] like Figure 2 As shown, the communication isolator 100 may include a first communication device 110 and a second communication device 120. The first communication device 110 and the second communication device 120 may be connected by a communication cable.

[0060] Specifically, the first communication device 110 may include a first communication module 111, a CPU module 112, a first power supply module 113, a second power supply module 114, a second communication module 115, a digital input signal (DI) module 116, a digital output signal (DO) module 117, an analog input signal (AI) module 118, and an analog output signal (AO) module 119.

[0061] The first communication module 111 can send and receive data or signals transmitted to or from the first control system 11 by communicating with the first control system 11. The first communication device 110 and the second communication device 120 can be connected by hardwire cable, tray flame-retardant PVC sheathed copper tape shield control cable (TRF-CVVS cable), but are not limited to these, and can be connected by various cables.

[0062] At least one of the digital input signal (DI) module 116, digital output signal (DO) module 117, analog input signal (AI) module 118, and analog output signal (AO) module 119 can be controlled by the CPU module 112. The signal generated by at least one of the digital input signal (DI) module 116, digital output signal (DO) module 117, analog input signal (AI) module 118, and analog output signal (AO) module 119 can be encoded or decoded under the control of the CPU module 112.

[0063] The second communication device 120 may include a first communication module 121, a CPU module 122, a first power supply module 123, a second power supply module 124, a second communication module 125, a digital output (DO) module 126, a digital input (DI) module 127, an analog output (AO) module 128, and an analog input (AI) module 129.

[0064] The first communication module 121 can send and receive data and signals by communicating with the second control system 12.

[0065] At least one of the digital output (DO) module 126, digital input (DI) module 127, analog output (AO) module 128, and analog input (AI) module 129 can be controlled by the CPU module 112. Signals generated by at least one of the digital output (DO) module 126, digital input (DI) module 127, analog output (AO) module 128, and analog input (AI) module 129 can be encoded or decoded under the control of the CPU module 112.

[0066] The first communication device 110 and the second communication device 120 can send and receive electrical signals through an electrical connection.

[0067] Here, the generated electrical signal can consist of digital input signal (DI), digital output signal (DO), analog input signal (AI), and analog output signal (AO). The transmission process of the electrical signal will be described below.

[0068] Figure 3 This is a diagram illustrating the process by which digital input signals (DI) of the first control system 11 are transmitted to the second control system 12 through the communication isolator 100.

[0069] For digital input signal (DI) particles, the first control system 11 can operate as a client. When the pump in the field is running, the contact point is energized and can be used as an internal signal input. The digital input signal (DI) can refer to the signal transmitted from the first control system 11 to the communication isolator 100. The input signal may include data, and the data included in the input signal is encoded or encapsulated, thereby converting it into a communication signal capable of communication. The converted communication signal can be transmitted to the communication isolator 100. Here, the conversion of the data included in the input signal into a communication signal is described, but it is not limited to this, and it can be converted into various formats capable of communication. Here, the communication signal refers to the signal transmitted from the first control system 11 to the communication isolator 100.

[0070] The first communication device 110 of the communication isolator 100 decodes or decapsulates the first communication signal TS1, thereby obtaining and determining the data (value) included in the first communication signal TS1. Here, the first communication signal TS1 refers to the signal transmitted from the first control system 11 to the communication isolator 100. Here, the data (value) can be any number corresponding to the binary bit string included in the signal.

[0071] The first communication device 110 of the communication isolator 100 can generate a signal corresponding to the data obtained from the first communication signal TS1 and transmit the signal to the second communication device 120. The first communication device 110 can determine whether the data obtained from the first communication signal TS1 is data stored in the first lookup table T1. When the corresponding data in the first lookup table T1 cannot be confirmed, the first communication device 110 may not perform any processing on the received signal. That is, the first communication device 110 may not generate a signal corresponding to the first communication signal TS1.

[0072] Here, as communication proceeds, the first lookup table T1 can be modified by the administrator. For example, when undefined data is received, it can be determined that the undefined data needs to be transmitted to another control system. The undefined data can be defined in the first lookup table T1. At this time, the communication isolator 100 can modify the first lookup table T1 to include the corresponding module and corresponding value for that data.

[0073] The second communication device 120 can use the received signal and the pre-stored second lookup table T2 to obtain data, and can generate a second communication signal including the data. Here, the second communication signal refers to the signal transmitted from the communication isolator 100 to the second control system 12. The digital output signal (DO) module of the second communication device 120 can transmit the communication signal to the second control system 12. The second lookup table T2 can include the signal, the data corresponding to the signal, and information for the corresponding module. The second lookup table T2 can be used to manage data related to digital signals and information for the modules that transmit digital signals.

[0074] For example, when the first communication signal TS1 generates a 0 to 5 V electrical signal in the first communication device 110, the digital input (DI) module 127 of the second communication device 120 detects the first communication signal TS1 through a wire or communication cable (unshielded twisted pair cable, UTP cable), such as a hard wire, and the DI module 127 can generate data corresponding to the signal by using a pre-stored second lookup table T2. Here, the communication cable (unshielded twisted pair cable, UTP cable) refers to a cable consisting of two strands twisted together without insulation, such as a straight cable or a crossover cable.

[0075] The second communication device 120 of the communication isolator 100 can encode or encapsulate the data corresponding to the signal and generate a second communication signal TS2, and can transmit the second communication signal TS2 to the second control system 12.

[0076] The communication isolator 100 can convert data and generate communication signals according to the first and second control systems of communication by using different lookup tables (first lookup table T1 and second lookup table T2). The communication isolator 100 converts received data by using the first lookup table T1 and the second lookup table T2, and can prevent unconverted data from being converted into communication signals.

[0077] In the second control system 12, the second communication signal TS2 is decoded or decapsulated, thereby converting it into data. The pump operating status of the facility can be provided through a user interface in the second control system 12. Users can learn about the operating status of the pumps connected to the first control system 11 through the second control system 12. That is, the second control system 12 can provide a user interface for data obtained from the second communication signal TS2 via the communication isolator 100. The second control system 12, as a central controller or a computer device in a secure area, may not receive communication signals and / or data not generated by the communication isolator 100, but is not limited to this. The second control system 12 can receive the operating status of the pumps connected to the first control system 11. When a signal meeting predetermined conditions is detected, the communication isolator 100 converts the signal through a predetermined process and transmits it to another control system, thereby allowing data transmission and reception between the first control system 11 and the second control system 12, which are connected via network communication.

[0078] Figure 4 This is a diagram illustrating the process by which digital signals from the second control system 12 are transmitted to the first control system 11 via the communication isolator 100.

[0079] The transmission flow of digital output signals (DO), as digital signals, can be from the first control system 11 to the first communication device 110, from the first communication device 110 to the second communication device 120, and from the second communication device 120 to the second control system 12. The first control system 11 can be connected to a pump, such as a power plant unit. Digital input signals (DI) can be transmitted from the second control system 12 to the second communication device 120, from the second communication device 120 to the first communication device 110, and from the first communication device 110 to the first control system 11. A user can generate input for the pump start button through the user interface of the second control system 12. When the pump start button is pressed, the second control system 12 converts the pump start input (Pump Run CMD Button Push) into a command signal CMD, and can generate communication signals by encapsulating or encoding the command signal CMD. The second control system 12 can transmit these communication signals to the first control system via the first communication device 110 and the second communication device 120.

[0080] The second communication device 120 of the communication isolator 100 receives the third communication signal TS3 from the second control system 12 and obtains the data by decapsulating or decoding it using a pre-stored lookup table T2. The communication isolator 100 can transmit electrical signals from the second control system 120 from its digital input signal (DI) module to the digital output signal (DO) module of the first communication device 110. Here, the third communication signal TS3 refers to the signal transmitted from the second control system 12 to the communication isolator 100.

[0081] The first communication device 110 of the communication isolator 100 can encode or encapsulate the signal and generate a fourth communication signal TS4. Here, the fourth communication signal TS4 refers to the signal transmitted from the communication isolator 100 to the first control system 11.

[0082] The generated fourth communication signal TS4 is transmitted to the first control system 11. In the first control system 11, the fourth communication signal TS4 can be decoded or decapsulated to obtain data. The first control system 11 can convert the data into a command signal and transmit it to the pump. The pump start input from the second control system 12 is transmitted to the first control system 11 through the communication isolator 100, thereby enabling the pump of the first control system to operate.

[0083] As described above, the command signals generated from the second control system 12, which is a computer device serving as a central controller or security zone, can be transmitted via a communication isolator to the first control system 11, which is connected to the actual device (pump, etc.).

[0084] Figure 5 This is a diagram used to describe the process of sending and receiving analog input signals (AI) through a communication isolator.

[0085] During the processing of the analog input signal (AI), the first control system 11 can be a client. When the pressure transmitter in the field measures a pressure value of a predetermined size (e.g., 5 Bar), it transmits an electrical signal with a preset current value (e.g., 20 mA) to the first control system 11.

[0086] The first control system 11 receives inputs of measured values ​​other than pressure, such as level, temperature, and water level, as analog signals, and converts these measured values ​​into corresponding current values, thereby generating analog signals of the corresponding current values. The measured values ​​can be, but are not limited to, temperature, level, water level, pressure, command values, flow rates, and analytical values, and can have various values.

[0087] The analog output module of the first control system 11 converts the pressure value from the field device into a communication signal, which can then be transmitted to the communication isolator 100.

[0088] The first communication device 110 of the communication isolator 100 can decapsulate or decode the first communication signal TS1 and generate data. The communication isolator 100 can use a pre-set second lookup table T2 to quantize the analog signal and convert it into an electrical signal. The second lookup table T2 may include the current value of the analog signal, the relationship between the data, and information for the signal receiving module. The first communication device 110 of the communication isolator 100 can use the second lookup table T2 to generate an electrical signal and transmit it to the second communication device 120 through the analog output signal (AO) module. The data corresponding to the signal '0011', i.e., 12 mA in the range of 4 mA to 20 mA, can be transmitted to the analog input signal AI module 129 of the second communication device 120 via cable. The analog input (AI) module 129 of the second communication device 120 encodes or encapsulates the received electrical signal '1010' using a pre-set fourth lookup table, thereby generating the second communication signal TS2 and transmitting it to the second control system 12. The first communication signal received from the first control system 11 and the second communication signal TS2 to be transmitted to the second control system 12 can be the same, but are not limited thereto.

[0089] The second control system 12 can decode or deencapsulate the received second communication signal TS2 and obtain the data '1000'. The second control system 12 obtains the pressure value through this process.

[0090] The second control system 12 can provide pressure values ​​through a user interface. For example... Figure 5 As shown, this can be provided by displaying it as a pressure value.

[0091] Figure 6 This is a diagram used to describe the process by which analog output signals (AO) are transmitted from the second control system 12 to the first control system 11 through a communication isolator.

[0092] The communication packet of the analog output signal is received from the second control system 12 in the form of a third communication signal TS3, and can be transmitted to the first control system 11 in the form of a fourth communication signal TS4. The third communication signal TS3 received from the second control system 12 and the fourth communication signal TS4 generated for transmission to the first control system 11 can be the same.

[0093] The transmission flow of the analog output signal (AO) can be the reverse order of the analog input signal (AI). When the user operates the valve 50% open command button through the user interface of the second control system 12, the valve 50% open command signal can be converted and generated.

[0094] The command signal (command signal, CMD) input by the user in the second control system 12 can be converted into a third communication signal TS3 for transmission to the communication isolator 100. The second control system 12 encodes or encapsulates the command signal to convert it into the third communication signal TS3. The third communication signal TS3 can be converted into a packet header including, but not limited to, elements such as SFD (Start Frame Delimeter) and HDR (Header).

[0095] The second control system 12 can transmit the third communication signal to the analog input (AI) module 129 of the communication isolator 100. The analog input module 129 of the second communication device 120 of the communication isolator 100 can decode or decapsulate the received third communication signal to obtain the electrical signal '1010'. The analog input (AI) module 129 of the second communication device 120 can transmit the signal to the analog output (AO) module 119 of the first communication device 110. The analog output (AO) module 119 of the communication isolator 100 can use a second lookup table to convert the received signal into data. The analog output (AO) module 119 of the communication isolator 100 encodes or encapsulates the data, thereby generating a fourth communication signal TS4 to be transmitted to the first control system 11. At this time, the data can be converted into a value that the first control system 11 can read. The communication isolator 100 can use different second lookup tables T2 to convert data and generate communication signals according to the communication between the first control system 11 and the second control system 12. The communication isolator 100 uses a second lookup table T2 to convert the received data and can prevent unconverted data from being converted into communication signals.

[0096] The analog output signal (AO) module of the communication isolator 100 can transmit the fourth communication signal to the first control system 11. The first control system 11 can then decode or decapsulate the received fourth communication signal to obtain data. The first control system 11 can then transmit a command signal to the valve via the data. For example, as input to the second control system 12, a command signal indicating that the valve is half-open can be transmitted to a device connected to the first control system. More specifically, the command signal transmitted to the device can be energized by a relay.

[0097] Examples of command signals transmitted to the device may include valve control signals, pressure control signals, and temperature control signals.

[0098] The first control system 11 can refer to a device installed in a power plant, factory, or building, but is not limited to these; it can be a device used in various industries.

[0099] In most industrial plants, multiple controllers are connected and communicate in real time. This communication allows various adverse effects, such as viruses and hacker attacks, to be accidentally transferred and cause serious consequences. To prevent this, firewalls, one-way communication, and communication monitoring equipment are used.

[0100] By using the communication isolator according to embodiments of this disclosure, existing communications can be maintained as is. Due to the principle of converting communications into electrical signals, users cannot communicate with any signals other than those preset, thus preventing unauthorized signals such as viruses from accessing the two controllers. Since the communication isolator according to this disclosure is a device that can be applied to both existing and new industrial plants, it is economically feasible in the future. Furthermore, with the development of information and communications technology (ICT), the size of the communication isolator 100 can be miniaturized, and devices using firmware and system-on-chip (SoC) can be miniaturized and updated. From the perspective of effectively protecting communications, this invention has significant market potential.

[0101] Figure 7 This is a flowchart of a communication isolation method according to an embodiment of the present invention.

[0102] In S110, the first communication device 110 of the communication isolator 100 can receive a first communication signal corresponding to a first signal output from the first control system 11. Here, the output can be a pump value, pressure value, temperature value, operating status, water level value, command value, flow rate value, and analysis value, etc., and the output can be a control signal generated in the control system. The output is not limited to these and can include various values ​​and signals.

[0103] In S120, the first communication device 110 can decode the first communication signal and obtain the first data.

[0104] In S130, the first communication device 110 can use a pre-stored lookup table to generate a second signal corresponding to the first data.

[0105] In S140, the second communication device 120 of the communication isolator 100 can receive a second signal from the first communication device 110.

[0106] In S150, the second communication device 120 can use the lookup table to convert the second signal into second data and encode the second data into a second communication signal.

[0107] In S160, the second communication device 120 can transmit the second communication signal to the second control system 12.

[0108] According to an embodiment of this disclosure, the second communication device 120 can receive a third communication signal corresponding to the first instruction signal from the central controller. The second communication device 120 decodes the third communication signal and converts it into third data, generates a third signal corresponding to the third data using a lookup table, and can transmit the third signal to the first communication device 110. The first communication device 110 converts the third signal into a fourth communication signal and transmits it to an external controller, which can then generate an instruction signal corresponding to the fourth communication signal and transmit it to an external utility device.

[0109] The apparatus described above can be implemented by hardware components, software components, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments can be implemented using one or more general-purpose computers or special-purpose computers, such as processors, controllers, arithmetic logic units (ALUs), digital signal processors (digital signal processors), microcomputers, field-programmable gate arrays (FPGAs), programmable logic units (PLUs), microprocessors, or any other apparatus capable of operating and responding to instructions. The processing apparatus can execute one or more software applications. The processing apparatus can execute on an operating system (OS) or execute software applications implemented by firmware. Furthermore, the processing apparatus can access, store, manipulate, process, and generate data in response to the execution of software. For ease of understanding, although examples are described using a single processing apparatus, those skilled in the art will understand that a processing apparatus can include a plurality of processing elements and / or a plurality of types of processing elements. For example, a processing apparatus can include a plurality of processors or a processor and a controller. Additionally, another processing configuration, such as a parallel processor, may be included.

[0110] Software may include computer programs, code, instructions, or a combination of at least one of these, and may configure a processing device to operate as needed, or to instruct the processing device independently or collectively. Software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave, to be interpreted by the processing device or to provide instructions or data to the processing device. Software may be distributed across computer systems connected via a network and stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

[0111] The method according to the embodiments can be implemented as program instructions executable by various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, and data structures, individually or in combination. The program instructions recorded in the medium may be specifically designed and configured for the embodiments, or may be known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical media such as CD-ROMs and DVDs; magneto-optical media such as floppy disks; and hardware devices specifically configured for storing and executing program instructions, such as read-only memory (ROM), random access memory (RAM), and flash memory. Examples of program instructions include not only machine language code such as that formed by an assembler, but also high-level language code that can be run by a computer using an interpreter. The hardware device may be configured to operate with at least one software module to perform the operations of the embodiments, and vice versa.

[0112] According to embodiments of this disclosure, communication between the control system installed in the industrial field and other controllers installed externally is physically isolated, thereby ensuring the operational integrity of the control system installed in the industrial field.

[0113] Furthermore, according to embodiments of this disclosure, while providing one-way communication via a firewall using a data diode, a commonly used technology, minimizes damage from viruses and network attacks, this disclosure can minimize damage from viruses and the like while providing two-way communication.

[0114] Furthermore, according to embodiments of this disclosure, first and second communication devices between the central controller and the external controller are used to shield the transmission and reception of data, thereby protecting the central controller and the external controller from damage such as viruses and network attacks.

[0115] Furthermore, according to embodiments of this disclosure, the generated digital and / or analog signals are converted into electrical signals and transmitted and received, thereby enabling bidirectional communication between the central controller and the external controller. Additionally, according to embodiments of this disclosure, the signals are converted into electrical signals and processed in the first and second communication devices, thereby enabling the transmission and reception of robust signals without interfering with bidirectional communication.

[0116] As described above, the embodiments are illustrated by way of defined examples and accompanying drawings, but those skilled in the art can make various modifications and variations based on the description. For example, suitable results can also be achieved when the described techniques are performed in a different order than the described methods, and / or when the constituent elements of the described systems, structures, devices, circuits, etc., are combined or integrated in a different form than the described methods, or when they are replaced or switched by another constituent element or equivalent.

[0117] Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the claims described below.

Claims

1. A communication isolator for network communication with a first control system and a second control system, the communication isolator comprising: A first communication device receives a first communication signal corresponding to a first signal output from the first control system, decodes the first communication signal to obtain first data, and generates a second signal corresponding to the first data using a pre-stored lookup table. as well as The second communication device receives the second signal from the first communication device, converts the second signal into second data using the lookup table, encodes the second data into a second communication signal, and transmits the second communication signal to the second control system. The second communication device receives a third communication signal corresponding to the first command signal from the second control system, decodes the third communication signal, converts it into third data, generates a third signal corresponding to the third data using the lookup table, and transmits the third signal to the first communication device. The first communication device converts the third signal into a fourth communication signal and transmits it to the first control system. In the first control system, a command signal corresponding to the fourth communication signal is generated. The first communication device is configured to generate the second signal only for predefined first data, and wherein the second signal is not generated when there is no value corresponding to the first data in the lookup table. The second communication device is configured to generate the third signal only for the predefined third data, and wherein the third signal is not generated when there is no value corresponding to the third data in the lookup table. The communication isolator generates data corresponding to digital signals by using the pre-stored lookup table, or by using different pre-set lookup tables, to quantize analog signals and convert them into electrical signals.

2. The communication isolator as described in claim 1, wherein, The first communication device and the second communication device are connected by a hard wire and send and receive signals.

3. The communication isolator as described in claim 1, wherein, The output of the first signal corresponds to a measured value or control signal corresponding to the first signal.

4. The communication isolator as described in claim 1, wherein, The first or second communication device is implemented by firmware.

5. A communication isolation method for a communication isolator that communicates with a first control system and a second control system via a network, the communication isolation method comprising: The first communication device of the communication isolator receives a first communication signal corresponding to a first signal output to the first control system. The first communication device decodes the first communication signal and obtains the first data; The first communication device uses a pre-stored lookup table to generate a second signal corresponding to the first data; The second communication device of the communication isolator receives the second signal from the first communication device; The second communication device uses the lookup table to convert the second signal into second data and encodes the second data into a second communication signal; as well as The second communication device transmits the second communication signal to the second control system, and The second communication device receives a third communication signal corresponding to the first command signal from the second control system; The second communication device decodes the third communication signal and converts it into third data, and uses the lookup table to generate a third signal corresponding to the third data, and transmits the third signal to the first communication device. The first communication device converts the third signal into a fourth communication signal and transmits it to the first control system. In the first control system, a command signal corresponding to the fourth communication signal is generated. The first communication device is configured to generate the second signal only for predefined first data, and wherein the second signal is not generated when there is no value corresponding to the first data in the lookup table. The second communication device is configured to generate the third signal only for the predefined third data, and wherein the third signal is not generated when there is no value corresponding to the third data in the lookup table. The communication isolator generates data corresponding to digital signals by using the pre-stored lookup table, or by using different pre-set lookup tables, to quantize analog signals and convert them into electrical signals.

6. The communication isolation method as described in claim 5, wherein, The first communication device and the second communication device are connected by a hard wire and send and receive signals.

7. The communication isolation method as described in claim 5, wherein, The output of the first signal corresponds to a measured value or control signal corresponding to the first signal.

8. A computer-readable storage medium storing a computer program that, when executed by a processor, performs the communication isolation method according to any one of claims 5 to 7.

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