CN220232289U - A programmable logic controller and control system - Google Patents

Abstract

This application provides a programmable logic controller and a control system, relating to the technical field of programmable logic controllers. The programmable logic controller includes: an input unit, a password transmission device, a processing unit and an output unit; the password transmission device is communicatively connected to the input unit and the processing unit respectively; the input unit is used to obtain the first control signal; the password transmission device is used to The first control signal is cryptographically calculated to obtain a second control signal, and the second control signal is forwarded to the processing unit; the processing unit is communicatively connected to the output unit; and the processing unit is used to forward the second control signal to the output unit. The programmable logic controller of this application solves the problem that the transmission of control signals is faced with increasingly frequent network attacks, resulting in a greatly increased probability of data leakage.

Description

A programmable logic controller and control system

Technical field

The present application relates to the field of programmable logic controllers, and in particular to a programmable logic controller and a control system.

Background technique

Programmable Logic Controller (PLC) is a kind of equipment that can be programmed. The programmable logic controller has powerful functions and is widely installed on various engineering machinery and equipment. Multiple programmable controllers form a control system. The main control device can control multiple controlled devices at the same time through the control system.

In the control system, the programmable controller deployed in the master station transmits control signals to the programmable controller deployed in the slave station. However, the transmission of control signals faces increasingly frequent cyber attacks, which greatly increases the probability of data leakage. Ensuring the safety and integrity of control signal transmission is an urgent problem that this utility model needs to solve.

Utility model content

This application provides a programmable logic controller and a control system to solve the problem that the transmission of control signals is faced with increasingly frequent network attacks, resulting in a greatly increased probability of data leakage.

In a first aspect, this application provides a programmable logic controller. The programmable logic controller includes: an input unit, a password transmission device, a processing unit and an output unit;

The password transmission device is communicatively connected with the input unit and the processing unit respectively;

Input unit, used to obtain the first control signal;

A cryptographic transmission device for cryptographically calculating the first control signal to obtain a second control signal, and forwarding the second control signal to the processing unit;

The processing unit is communicated with the output unit;

A processing unit configured to forward the second control signal to the output unit.

In a possible design, the cryptographic transmission device includes: a computing chip and an interface circuit;

The computing chip is communicated with the input unit;

A computing chip, used for encrypting or decrypting the first control signal to obtain the second control signal;

The interface circuit is communicated with the computing chip and the processing unit respectively;

The interface circuit is used to forward the second control signal to the processing unit.

In a possible design, the cryptographic transmission device also includes: an analysis chip;

The analysis chip is communicated with the input unit and the computing chip respectively;

An analysis chip is used to analyze the first control signal and obtain analysis results;

The analysis chip is also configured to forward the first control signal to the operation chip when the analysis result is a first result, wherein the first result is used to indicate the cryptographic operation first control signal.

In one possible design, the analysis chip is communicatively connected to the processing unit;

The analysis chip is also configured to transparently transmit the first control signal to the processing unit when the analysis result is a second result, where the second result is used to indicate transparent transmission of the first control signal;

The processing unit is also used to forward the first control signal to the output unit.

In a possible design, the password transmission device also includes: a control chip;

Communication connection between control chip and computing chip;

The control chip is used to start the computing chip when the analysis result is the first result, and to stop the computing chip when the analysis result is the second result.

In one possible design, the programmable logic controller is deployed at the master station;

The input unit is communicated with the main control device;

The output unit is communicatively connected to the programmable logic controller deployed in the slave station;

The computing chip is specifically used to encrypt and compute the first control signal to obtain the second control signal.

In one possible design, programmable logic controllers are deployed in slave stations;

The input unit is communicatively connected to the programmable logic controller deployed on the main station;

The output unit communicates with the controlled device;

The computing chip is specifically used to decrypt and compute the first control signal to obtain the second control signal.

In a possible design, the programmable logic controller also includes: an indication unit, a storage unit and an expansion unit;

The instruction unit, storage unit and expansion unit are respectively communicatively connected with the processing unit;

Indicating unit, used to indicate the status of the programmable logic controller;

The storage unit includes a read-only memory and a random access memory, and the read-only memory and the random access memory are respectively communicatively connected with the processing unit;

The expansion unit communicates with third-party devices.

In a possible design, the indication unit includes: a first display light, a second display light and a third display light;

The first display light, the second display light and the third display light are respectively communicatively connected with the processing unit;

The first display light is used to indicate the operating status, which includes equipment startup and equipment shutdown;

The second display light is used to indicate abnormal status, which includes connection timeout and connection interruption;

The third display light is used to indicate the interface status. The interface status includes interface connection and interface disconnection.

In a second aspect, this application provides a control system, which includes: a plurality of programmable logic controllers as in any one of the first aspect that are communicatively connected in a star topology structure.

This application provides a programmable logic controller and a control system. The programmable logic controller includes: an input unit, a password transmission device, a processing unit and an output unit. The password transmission device is communicatively connected to the input unit and the processing unit respectively. The processing unit Communicate with the output unit. The following technical effects are achieved: the first control signal is cryptographically calculated by the cryptographic transmission device to obtain and transmit the second control signal, which solves the problem that the transmission of control signals is faced with increasingly frequent network attacks, resulting in a greatly increased probability of data leakage; By controlling the various units and devices of the programmable logic controller through the processing unit, the problem of mutual coordination of the various units and devices of the programmable logic controller is solved; the first control signaling is obtained from other PLCs or master control devices through the input unit, and The second control signal is sent to other PLCs or controlled devices through the output unit, thereby solving the problem of the programmable logic controller transmitting control signals.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description The drawings illustrate some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic diagram of an application scenario of a programmable logic controller provided by an embodiment of the present application;

Figure 2 is a schematic structural diagram of a programmable logic controller provided by an embodiment of the present application;

Figure 3 is a schematic structural diagram 2 of a programmable logic controller provided by an embodiment of the present application;

Figure 4 is a schematic structural diagram three of a programmable logic controller provided by an embodiment of the present application;

Figure 5 is a schematic structural diagram 4 of a programmable logic controller provided by an embodiment of the present application;

Figure 6 is a schematic structural diagram 5 of a programmable logic controller provided by an embodiment of the present application;

Figure 7 is a schematic structural diagram 6 of a programmable logic controller provided by an embodiment of the present application;

Figure 8 is a schematic structural diagram 7 of a programmable logic controller provided by an embodiment of the present application;

Figure 9 is a schematic structural diagram of a control system provided by an embodiment of the present application.

Reference signs:

100-control computer;

200-Control system; 210-Programmable logic controller; 220-Input unit; 230-Password transmission device; 231-Arithmetic chip; 232-Interface circuit; 233-Analysis chip; 234-Control chip; 240-Processing unit; 250 -Output unit; 260-indicating unit; 261-first display light; 262-second display light; 263-third display light; 270-storage unit; 280-extension unit;

300-automatic guided vehicle; 310-hoisting system; 320-travel system.

Detailed ways

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this application. Rather, they are merely examples of apparatus and programmable logic controllers consistent with aspects of the application as detailed in the appended claims.

In the embodiments of the present application, words such as “first” and “second” are used to distinguish identical or similar items with basically the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the number and execution order, and words such as "first" and "second" do not limit the number and execution order. It should be noted that in the embodiments of this application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design described herein as "exemplary" or "such as" is not intended to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the words "exemplary" or "such as" is intended to present the concept in a concrete manner. In the embodiments of this application, "at least one" refers to one or more, and "multiple" refers to two or more.

It should be noted that "at..." in the embodiments of the present application can be the instant when a certain situation occurs, or it can be a period of time after a certain situation occurs. The embodiments of the present application do not specify this. limited. In addition, the programmable logic controller provided in the embodiments of this application is only an example, and the programmable logic controller may also include more or less content.

In order to facilitate a clear description of the technical solutions of the embodiments of the present application, some terms and technologies involved in the embodiments of the present application are briefly introduced below:

Cryptographic operations: It is a data processing method. Cryptographic operations include encryption operations or decryption operations.

Encryption operation: It is a cryptographic operation. Encryption operations use encryption algorithms to encrypt originally readable plaintext data into unreadable ciphertext data.

Decryption operation: It is a cryptographic operation. The decryption operation decrypts the originally unreadable ciphertext data into readable plaintext data through the decryption algorithm.

Transparent transmission: It is a data processing method. Transparent transmission means transparent transmission, that is, only data is transmitted without any changes or adjustments. All format contents of the data before and after it is sent are consistent, which greatly ensures the integrity of the data.

Star topology: It is a network topology. In a star topology, each network node is connected to a central node in a point-to-point manner, and the central node transmits information to the destination node.

PLC is the brain of engineering machinery and equipment and an indispensable part of it. During the operation of construction machinery and equipment, PLC makes real-time decisions to control the execution devices of construction machinery and equipment to perform preset tasks. Specifically, PLC controls the servo motor (such as controlling torque, controlling steering or controlling speed, etc.) and drives the lower-level external power device (such as mechanical arm, driving system or hydraulic system).

With the rapid development of industrial automation, in order to achieve more complex functions, the main control device is required to control multiple controlled devices at the same time. An effective solution is to form a control system with multiple PLCs, including one PLC deployed at the master station, that is, the master station PLC, and multiple PLCs deployed at the slave stations, that is, the slave station PLC. The master station PLC simultaneously controls multiple slave station PLCs through control signals, and the master control device simultaneously controls multiple controlled devices through the control system.

Along with this, ensuring the security and integrity of control signal transmission has become increasingly important. The reason is that, first, the core competitiveness and business secrets of an enterprise can be analyzed through control signals, such as production processes, product designs, and market strategies. If these data are obtained by unauthorized personnel, it will affect the interests and reputation of the enterprise. Cause serious damage; secondly, with the rapid development of wireless connections, the master station PLC and slave station PLC are connected wirelessly. Correspondingly, the transmission of control signals is facing increasingly frequent network attacks, resulting in a high probability of data leakage. improve.

Based on this, embodiments of the present application provide a programmable logic controller and a control system, which can be used in the technical field of programmable logic controllers, aiming to solve the problem that the transmission of control signals is faced with increasingly frequent network attacks, resulting in extremely high probability of data leakage. A big improvement question.

Figure 1 is a schematic diagram of an application scenario of a programmable logic controller provided by an embodiment of the present application. It should be noted that Figure 1 shows only one possible application scenario to help those skilled in the art understand the technical content of the present application, but does not mean that the embodiment of the present application cannot be used in other application scenarios. As shown in Figure 1, the application scenarios of the programmable logic controller include: control computer 100, control system 200 and automatic guided vehicle 300. The control system 200 includes three programmable logic controllers 210 , and the automatic guided vehicle 300 includes a hoisting system 310 and a traveling system 320 .

The control computer 100 is the main control device. The operator controls the hoisting system 310 to drive the automatic guided vehicle 300 to travel on the control computer 100 by inputting commands, graphical operations, or automated programs, and/or controls the traveling system 320 to hoist goods. In addition to the examples given in this application scenario, the main control device can also be a desktop computer, a smartphone, a control server or an operating dashboard.

The first programmable logic controller 210 is the master programmable logic controller. The first programmable logic controller 210 is communicatively connected to the control computer 100, and is wirelessly connected to the second programmable logic controller 210 and the third programmable logic controller 210 respectively. The communication connections may include various connection types, For example, wired or wireless communication links or fiber optic cables, etc. The first programmable logic controller 210 can be deployed on the control computer 100, on the automatic guided vehicle 300, or at other locations. The first programmable logic controller 210 is used to forward the control signal sent by the control computer 100 to the second programmable logic controller 210 or the third programmable logic controller 210, for example, to control the control of the hoisting system 310. The signal is forwarded to the second programmable logic controller 210 so that the control signal is forwarded to the hoisting system 310; for another example, the control signal for controlling the driving system 320 is forwarded to the third programmable logic controller 210 so that the control signal is forwarded to the hoisting system 310. The control signal is forwarded to the driving system 320 .

The second programmable logic controller 210 is a slave programmable logic controller. The second programmable logic controller 210 is communicatively connected with the hoisting system 310 . The second programmable logic controller 210 can be deployed on the hoisting system 310, on the automatic guided vehicle 300, or at other locations. The second programmable logic controller 210 is used to forward control signals to the hoisting system 310 .

The third programmable logic controller 210 is a slave programmable logic controller. The third programmable logic controller 210 is communicatively connected with the driving system 320 . The third programmable logic controller 210 can be deployed on the driving system 320, on the automatic guided vehicle 300, or at other locations. The third programmable logic controller 210 is used to forward control signals to the driving system 320 .

The automatic guided vehicle 300 is a controlled device. The automatic guided vehicle 300 is used to hoist and carry goods, and transport the goods to designated locations. The hoisting system 310 is specifically used to output different torques, rotational speeds and steering according to the control signal to drive the automatic guided vehicle 300 forward, backward or steering. The driving system 320 is specifically used to hoist goods from under the vehicle to the vehicle, or to hoist goods from the vehicle to the vehicle under the vehicle according to the control signal. In addition to the examples given in this application scenario, the controlled equipment can also be other engineering machinery and equipment, such as inspection equipment, lifting machinery or production lines, etc. Construction machinery equipment is equipped with multiple drive systems, and each slave programmable logic controller controls several drive systems.

FIG. 2 is a schematic structural diagram of a programmable logic controller provided by an embodiment of the present application. As shown in Figure 2, the programmable logic controller 210 includes: an input unit 220, a password transmission device 230, a processing unit 240 and an output unit 250;

The password transmission device 230 is communicatively connected with the input unit 220 and the processing unit 240 respectively;

Specifically, the input unit 220 is a transmission interface, and different types of access devices are connected to the input unit 220. Among them, other PLCs (when the programmable logic controller 210 is the main station programmable logic controller, the other PLCs are Slave programmable logic controller; when the programmable logic controller 210 is a slave programmable logic controller, other PLCs (master programmable logic controller) access the input unit 220 through wireless communication connections, and the master control The device accesses the input unit 220 through a wired communication connection or a wireless communication connection; the wireless communication connection method can be fifth generation mobile communication technology (5th Generation Mobile Communication Technology, 5G), long range radio (Long Range Radio, LoRa) or Wireless network communication technology (WIreless Fidelity, WiFi), etc.; wired communication connection methods can be controller area network (Controller Area Network, CAN) bus, universal serial bus (Universal SerialBus, USB) bus or network cable, etc. The input unit 220 is used to acquire the first control signal, which may be acquired from other PLCs or from the main control device.

The password transmission device 230 is a device for processing data. The password transmission device 230 is communicatively connected to the input unit 220. The password transmission device 230 is used to cryptographically calculate the first control signal to obtain the second control signal, and forward the second control signal to the processing unit 240. The cryptographic operation is an encryption operation or a decryption operation; the cryptographic transmission device 230 is communicatively connected to the processing unit 240, and the cryptographic transmission device 230 sends the second control signal to the processing unit 240.

The processing unit 240 is communicatively connected with the output unit 250;

Specifically, the processing unit 240 is a chip that operates data. The password transmission device 230 may be a central processing unit (CPU), a microcontroller unit (MCU), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC) or a field programmable gate array (FieldProgrammable Gate Array, FPGA). )wait. The processing unit 240 is communicatively connected with the output unit 250 , and the processing unit 240 is configured to forward the second control signal to the output unit 250 .

The processing unit 240 controls each unit and device in the programmable logic controller 210. The processing unit 240 is also used to control the input unit 220 to obtain the first control signaling from other PLCs or master control devices, and control the password transmission device 230 according to the first control The signal obtains a second control signal, and the control output unit 250 sends the second control signal to other PLCs or controlled devices.

The output unit 250 is a transmission interface, and the output unit 250 is connected to different types of access devices. Among them, the output unit 250 is connected to other PLCs through wireless communication connections, and is connected to the controlled equipment through wired communication connections or wireless communication connections. The output unit 250 sends the second control signal to other PLCs or controlled devices, so as to control the controlled devices to perform preset actions according to the second control signal.

This embodiment provides a programmable logic controller. The programmable logic controller includes: an input unit, a password transmission device, a processing unit and an output unit. The password transmission device is communicatively connected to the input unit and the processing unit respectively. The processing unit is connected to the output unit. Unit communication connection. The following technical effects are achieved: the first control signal is cryptographically calculated by the cryptographic transmission device to obtain and transmit the second control signal, which solves the problem that the transmission of control signals is faced with increasingly frequent network attacks, resulting in a greatly increased probability of data leakage; By controlling the various units and devices of the programmable logic controller through the processing unit, the problem of mutual coordination of the various units and devices of the programmable logic controller is solved; the first control signaling is obtained from other PLCs or master control devices through the input unit, and The second control signal is sent to other PLCs or controlled devices through the output unit, thereby solving the problem of the programmable logic controller transmitting control signals.

Figure 3 is a schematic second structural diagram of a programmable logic controller provided by an embodiment of the present application. FIG. 3 explains the password transmission device 230 in detail on the basis of FIG. 2 . As shown in Figure 3, the password transmission device 230 includes: a computing chip 231 and an interface circuit 232;

The computing chip 231 is communicatively connected with the input unit 220;

The interface circuit 232 is communicatively connected with the computing chip 231 and the processing unit 240 respectively;

Specifically, the computing chip 231 is a chip specially used to implement data encryption and decryption. The computing chip 231 may be an ATSHA204A series chip, a PN7462 series chip, or other encryption chips. The computing chip 231 supports a variety of algorithms and protocols, and implements encryption algorithms or decryption algorithms through hardware support to achieve more secure and efficient encryption or decryption operations. The computing chip 231 is used for encrypting or decrypting the first control signal to obtain the second control signal.

The interface circuit 232 is a circuit that functions as a connection, and the interface circuit 232 is used to forward the second control signal to the processing unit 240 . The interface circuit 232 includes a serial peripheral (Serial Peripheral Interface, SPI) interface, a logic level conversion device, and a filtering/isolating device. The SPI interface is communicatively connected to the computing chip 231 , and the filtering/isolating device is communicatively connected to the processing unit 240 .

The SPI interface is used for data communication between the master device (such as the computing chip 231) and the slave device (such as the processing unit 240). The SPI interface is a synchronous, full-duplex communication protocol.

The logic level conversion device is used to convert the logic level of the operation chip 231 into the logic level of the processing unit 240 . When the computing chip 231 and the processing unit 240 use different logic levels, the logic level conversion device ensures the compatibility of their signals. The logic level conversion device is a mature circuit structure, which is composed of electronic components such as transistors, level shifters, and level comparators. It uses level shifting or level comparison to achieve logic level conversion.

Filtering/isolation devices are used to reduce electromagnetic interference and isolate interference between different parts, thereby improving the reliability and stability of communication. They are commonly used circuit components in electronic systems. Filtering/isolation devices include filtering devices and isolation devices. Filtering devices are usually composed of capacitors, inductors, resistors and other components. They are used to filter out high-frequency noise, interference and harmonics in control signals to maintain the clarity of control signals; isolation The device is used to isolate interference between the computing chip 231 and the processing unit 240 to prevent interference signals from affecting other devices and units.

In one possible design, FIG. 4 is a schematic structural diagram 3 of a programmable logic controller provided by an embodiment of the present application. FIG. 4 explains the password transmission device 230 in detail on the basis of FIG. 3 . As shown in Figure 4, the password transmission device 230 also includes: an analysis chip 233;

The analysis chip 233 is communicatively connected to the input unit 220 and the computing chip 231 respectively;

Specifically, the analysis chip 233 is a circuit that analyzes and forwards data. The analysis chip 233 may be a CPU, MCU, ASIC or FPGA, etc. The analysis chip 233 determines whether to perform an encryption operation or a decryption operation on the first control signal according to preset rules and strategies. For example, the analysis chip 233 monitors the security and sensitivity of the first control signal in real time and identifies potential threats therein to ensure the security and integrity of the control signal during transmission and storage. The analysis chip 233 is used to analyze the first control signal to obtain the analysis result; when the analysis result is the first result, the first control signal is forwarded to the arithmetic chip 231 so that the arithmetic chip 231 cryptographically calculates the first control signal to obtain the second control signal, and forward the second control signal to the output unit 250 through the processing unit 240, where the first result is used to indicate the cryptographic operation of the first control signal.

In one possible design, FIG. 5 is a schematic structural diagram 4 of a programmable logic controller provided by an embodiment of the present application. FIG. 5 explains the password transmission device 230 in detail based on FIG. 4 . As shown in Figure 5, the analysis chip 233 is communicatively connected with the processing unit 240;

Specifically, when the analysis result is the second result, the first control signal is forwarded to the processing unit 240 so that the processing unit 240 forwards the first control signal to the output unit 250, where the second result is used to indicate transparent transmission. first control signal.

In one possible design, FIG. 6 is a schematic structural diagram 5 of a programmable logic controller provided by an embodiment of the present application. FIG. 6 explains the password transmission device 230 in detail on the basis of FIG. 5 . As shown in Figure 6, the password transmission device 230 also includes: a control chip 234;

The control chip 234 is communicatively connected with the computing chip 231;

Specifically, the control chip 234 is a chip specially used to control the computing chip 231 . The control chip 234 may be a chip of the A71CH series, a chip of the OPTIGA Trust series, or a chip of the ATECC608A series. The control chip 234 is used to control the start, stop, parameter setting and other functions of the computing chip 231. It is an important component of the password transmission device 230. It is specifically used for: first, starting the computing chip 231 when the analysis result is the first result; When the analysis result is the second result, stop the computing chip 231 to ensure that the computing chip 231 only runs when needed, thereby saving the system resources of the programmable logic controller 210; second, control the computing chip 231 to select different algorithms and protocols, And configure the configuration parameters of the computing chip 231 to ensure that the computing chip 231 can perform encryption operations or decryption operations; third, monitor the status of the password transmission device 230, including power status, encryption status, error status, etc., to ensure that the password transmission device 230 Normal operation; fourth, control and manage each chip and power of the password transmission device 230.

In one possible design, the programmable logic controller 210 is deployed at the main station;

The input unit 220 is communicatively connected with the main control device;

The output unit 250 is communicatively connected with the programmable logic controller deployed in the slave station;

Specifically, when the programmable logic controller 210 is deployed at the main station, it is the main station programmable logic controller. The input unit 220 obtains the first control signal from the main control device (such as the control computer 100 in Figure 1), and the first control signal is readable plain text data; the computing chip 231 encrypts the first control signal to obtain the second control signal, The second control signal is unreadable cipher text data; the output unit 250 sends the second control signal to the slave programmable logic controller.

In one possible design, the programmable logic controller 210 is deployed in the slave station;

The input unit 220 is communicatively connected to the programmable logic controller 210 deployed on the main station;

The output unit 250 is communicatively connected with the controlled device;

Specifically, when the programmable logic controller 210 is deployed in a slave station, it is a slave station programmable logic controller. The input unit 220 obtains the first control signal from the master station programmable logic controller, and the first control signal is unreadable cipher text data; the computing chip 231 decrypts and operates the first control signal to obtain a second control signal, and the second control signal is Readable plain text data; the output unit 250 sends the second control signal to the controlled device (for example, the hoisting system 310 or the driving system 320 in Figure 1).

In one possible design, FIG. 7 is a schematic structural diagram 6 of a programmable logic controller provided by an embodiment of the present application. FIG. 7 explains the programmable logic controller 210 in detail based on FIG. 6 . As shown in Figure 7, the programmable logic controller 210 also includes: an indication unit 260, a storage unit 270 and an expansion unit 280;

The instruction unit 260, the storage unit 270 and the expansion unit 280 are respectively communicatively connected with the processing unit 240;

The storage unit 270 includes a read-only memory and a random access memory, and the read-only memory and the random access memory are respectively communicatively connected with the processing unit 240;

The expansion unit 280 communicates with third-party devices;

Specifically, the indication unit 260 is a device for providing external prompts. The indication unit 260 may be an optical device, for example, prompting through a display light; it may also be an acoustic device, for example, prompting through a speaker; or it may be other unlisted devices. The indication unit 260 is used to indicate the status of the programmable logic controller 210. The status of the programmable logic controller 210 is determined by the processing unit 240, and the processing unit 240 controls the indication unit 260 to prompt.

The storage unit 270 is a device that stores data. The storage unit 270 includes read-only memory (Read-OnlyMemory, ROM) and random access memory (Random Access Memory, RAM). ROM works in a non-destructive reading mode. It can only read information but cannot write it. Once the information is written, it is fixed. Even if the power is cut off, the information will not be lost. The system level and user program of the PLC are stored in the ROM. System programs and user programs can be stored in one partition or in different partitions. RAM can be read and written at any time, and it is very fast. When RAM is working, it can write (store) or read (retrieve) information from any specified address at any time. The biggest difference between RAM and ROM is the volatility of data, that is, Once the power is turned off, the stored data will be lost, and temporary data and intermediate results are stored in RAM.

The extension unit 280 is a transmission interface, and different types of third-party devices access the extension unit 280. Third-party devices can be external devices such as monitors and printers, making the configuration of the programmable logic controller 210 more flexible to meet the needs of different control systems and operators.

In other embodiments, the programmable logic controller 210 further includes: a power supply device, which is used to convert 220V AC power into DC power available for each unit and device, and to provide power to each unit and device.

In one possible design, FIG. 8 is a schematic structural diagram 7 of a programmable logic controller provided by an embodiment of the present application. FIG. 8 explains the instruction unit 260 in detail based on FIG. 7 . As shown in Figure 3, the indication unit 260 includes: a first display light 261, a second display light 262 and a third display light 263;

The first display light 261, the second display light 262 and the third display light 263 are respectively communicatively connected with the processing unit 240;

Specifically, the first display lamp 261, the second display lamp 262 and the third display lamp 263 may be light emitting diodes (Light Emitting Diodes, LEDs) or filament indicator lamps, with different colors or different flicker evaluations. rate, indicating different content.

The first display light 261 is used to indicate the operating status, which includes the device being turned on and the device being turned off; for example, when the first display light 261 is solid green, it indicates that the programmable logic controller 210 is in the operating state of the device being turned on; in the When a display light 261 is always blue, it indicates that the programmable logic controller 210 is in a device shutdown operating state.

The second display light 262 is used to indicate an abnormal state, which includes connection timeout and connection interruption; for example, when the second display light 262 is solid green, it indicates that the programmable logic controller 210 is not in an abnormal state; when the second display When the light 262 is solid yellow, it indicates that the programmable logic controller 210 is in an abnormal state of connection timeout. The abnormal state of connection timeout refers to the connection between the programmable logic controller 210 and the master control device, the master station programmable logic controller, and the slave. The connection between the station programmable logic controller or the controlled device times out; when the second display light 262 flashes yellow, it indicates that the programmable logic controller 210 is in an abnormal state of connection interruption. The abnormal state of connection interruption means that the programmable logic controller 210 is in an abnormal state of connection interruption. The connection between the logic controller 210 and the master control device, the master station programmable logic controller, the slave station programmable logic controller or the controlled device is interrupted, or several devices or units in the programmable logic controller 210 fail, Failures are software failures and/or hardware failures.

The third display light 263 is used to indicate the interface status, which includes interface connection and interface disconnection; for example, when the third display light 263 is solid green, it indicates the interface connection of the input unit 220 and the output unit 250; When the display light 263 is solid yellow, it indicates that the input unit 220 and/or the output unit 250 are being plugged or unplugged.

This embodiment provides a programmable logic controller. The programmable logic controller includes: an input unit, a password transmission device, a processing unit and an output unit. The password transmission device is communicatively connected to the input unit and the processing unit respectively. The processing unit is connected to the output unit. Unit communication connection. The following technical effects are achieved: the first control signal is cryptographically calculated by the cryptographic transmission device to obtain and transmit the second control signal, which solves the problem that the transmission of control signals is faced with increasingly frequent network attacks, resulting in a greatly increased probability of data leakage; By controlling the various units and devices of the programmable logic controller through the processing unit, the problem of mutual coordination of the various units and devices of the programmable logic controller is solved; the first control signaling is obtained from other PLCs or master control devices through the input unit, and The second control signal is sent to other PLCs or controlled equipment through the output unit, which solves the problem of programmable logic controller transmitting control signals; through the computing chip, interface circuit, analysis chip and control chip, the first control signal is cryptographically calculated, Alternatively, transparently transmitting the first control signal solves the problem of different safety and sensitivity requirements of the first control signal; indicating the operating status, abnormal status and interface status of the programmable logic controller through indicator lights, solving the problem that the operator cannot Know the status of the programmable logic controller in a timely manner.

Figure 9 is a schematic structural diagram of a control system provided by an embodiment of the present application. As shown in Figure 9, the control system 200 includes: a plurality of programmable logic controllers 210 of the above embodiments communicatively connected in a star topology structure.

The implementation principles and technical effects of the control system provided by this embodiment are similar to those of a programmable logic controller in the above embodiment, and will not be described again in this embodiment.

So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the drawings. However, those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. The above embodiments are only It is used to illustrate the technical solution of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still apply the technology described in the foregoing embodiments. Modify the solution, or make equivalent substitutions for some or all of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solution to depart from the scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. A programmable logic controller, characterized in that the programmable logic controller includes: an input unit, a password transmission device, a processing unit and an output unit; The password transmission device is communicatively connected to the input unit and the processing unit respectively; The input unit is used to obtain the first control signal; The cryptographic transmission device is used to cryptographically calculate the first control signal to obtain a second control signal, and forward the second control signal to the processing unit; The processing unit is communicatively connected to the output unit; The processing unit is configured to forward the second control signal to the output unit. 2. The programmable logic controller according to claim 1, characterized in that the password transmission device includes: a computing chip and an interface circuit; The computing chip is communicatively connected to the input unit; The operation chip is used for encryption operation or decryption operation of the first control signal to obtain a second control signal; The interface circuit is communicatively connected to the computing chip and the processing unit respectively; The interface circuit is used to forward the second control signal to the processing unit. 3. The programmable logic controller according to claim 2, wherein the password transmission device further includes: an analysis chip; The analysis chip is communicatively connected to the input unit and the computing chip respectively; The analysis chip is used to analyze the first control signal and obtain analysis results; The analysis chip is also configured to forward the first control signal to the operation chip when the analysis result is a first result, wherein the first result is used to indicate cryptographic operation of the first control signal. Signal. 4. The programmable logic controller according to claim 3, wherein the analysis chip is communicatively connected to the processing unit; The analysis chip is also configured to transparently transmit the first control signal to the processing unit when the analysis result is a second result, wherein the second result is used to indicate transparent transmission of the first control signal. control signal; The processing unit is also used to forward the first control signal to the output unit. 5. The programmable logic controller according to claim 4, wherein the password transmission device further includes: a control chip; The control chip is communicatively connected to the computing chip; The control chip is used to start the computing chip when the analysis result is the first result, and to stop the computing chip when the analysis result is the second result. 6. The programmable logic controller according to claim 5, characterized in that the programmable logic controller is deployed at the main station; The input unit is communicatively connected with the main control device; The output unit is communicatively connected with a programmable logic controller deployed in the slave station; The computing chip is specifically used to encrypt and compute the first control signal to obtain the second control signal. 7. The programmable logic controller according to claim 5, characterized in that the programmable logic controller is deployed in a slave station; The input unit is communicatively connected with a programmable logic controller deployed on the main station; The output unit is communicatively connected with the controlled device; The computing chip is specifically used to decrypt and compute the first control signal to obtain the second control signal. 8. The programmable logic controller according to claim 6 or 7, characterized in that the programmable logic controller further includes: an indication unit, a storage unit and an expansion unit; The indication unit, storage unit and expansion unit are respectively communicatively connected with the processing unit; The indicating unit is used to indicate the status of the programmable logic controller; The storage unit includes a read-only memory and a random access memory, and the read-only memory and the random access memory are respectively communicatively connected with the processing unit; The expansion unit is communicatively connected with a third-party device. 9. The programmable logic controller according to claim 8, wherein the indication unit includes: a first display light, a second display light and a third display light; The first display light, the second display light and the third display light are respectively communicatively connected with the processing unit; The first display light is used to indicate operating status, and the operating status includes equipment startup and equipment shutdown; The second display light is used to indicate abnormal status, and the abnormal status includes connection timeout and connection interruption; The third display light is used to indicate interface status. The interface status includes interface connection and interface disconnection. 10. A control system, characterized in that the system includes: a plurality of programmable logic controllers according to any one of claims 1 to 9, communicatively connected in a star topology structure.