PLC Authorization Expiration Shutdown System Based on Multicast Protocol

Abstract

An embodiment of the present invention provides a PLC authorization expiration shutdown system based on a multi-point communication protocol. The system includes: a startup and shutdown system circuit board, an on-board non-contact CPU card reader / writer, and a non-contact CPU card. Among them, the non-contact CPU card is used to store PLC allowed running time data; the on-board non-contact CPU card reader / writer is used to obtain the PLC allowed running time data and send the PLC allowed running time data to the startup and shutdown system circuit board; the startup and shutdown system circuit board includes an on-board multi-point communication interface, an on-board non-contact CPU card reader / writer interface, and a control circuit for issuing an authorization expiration shutdown command to the target PLC based on the PLC allowed running time data. The embodiment of the present invention can realize the startup and shutdown management of the PLC without programming on the PLC or modifying the original program, and the implementation is simple and convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial automatic control, and more specifically, to a PLC authorization expiration shutdown system based on a multi-point communication protocol. Background Art

[0002] The Programmable Logic Controller (PLC) is the core component of many small and medium-sized industrial automatic control devices. During the operation of automatic control devices, in many application scenarios, the operation mode of the PLC is switched from the RUN mode to the STOP mode, or from the STOP mode to the RUN mode. Common application scenarios include: 1) When the operator has checked that the preconditions such as the integrity of the equipment are met, a person with a higher level needs to switch the PLC from the STOP mode to the RUN mode; 2) When an emergency or other situation occurs in the equipment, it is necessary to stop the machine, that is, switch from the RUN mode to the STOP mode. In particular, equipment leasing, as a way of equipment sharing, helps to save energy and reduce resource consumption. When the leasing fee is not paid in time, due to the long distance and inconvenient transportation, some equipment is still underground in coal mines and other reasons, resulting in the lessor being unable to directly recover the equipment, or the recovery and transportation cost is high; sometimes customers also have repeated leasing needs and still need to lease after renewal, and there is no need to return the leased equipment, but the PLC needs to be placed in the STOP mode, and the equipment cannot be used temporarily to remind the customer to pay or renew the fee.

[0003] Currently, there are two common methods for PLC startup and shutdown management. The first method is to write a corresponding program segment in the running program inside the PLC to control the state of the PLC. This method mainly has two technical problems: First, the program is easily tampered with by unauthorized personnel, and the equipment manager will not be able to control its RUN and STOP states; Second, for leased equipment, the original program is modified, and the property rights of many equipment belong to a third party, and their models are officially certified and are all controlled. Modifying these programs requires authorization.

[0004] Secondly, the second method that can be adopted is to configure the master computer software and set user names and passwords to control and manage the right of use. There are also two technical problems in this method: First, not all PLCs are configured with a master computer. In many occasions with strong mobility, independent functionality, and explosion-proof requirements, most do not have a dedicated master computer with an operable password setting function. Especially in some extremely vibrating stone-breaking and quarrying occasions, the cost of selecting and configuring the corresponding master computer is extremely high. In such PLC application occasions without a master computer, it causes unnecessary high costs. Second, the general PLC master computer software, such as various domestic and imported configuration software, is costly. Even if one spends money to purchase Siemens monitoring products or configuration software from third-party manufacturers, or adopts other communication methods, there are limitations such as complex programming, the need to purchase software and authorization licenses. If a user wants to control the PLC, they also need to configure the computer operating platform required for this monitoring and configuration software. Therefore, it is also unrealistic to specifically set up a master computer to control its usage rights.

[0005] Therefore, there is an urgent need to provide a new PLC start-stop management method or system to solve the problems such as the program being easily tampered with, the need for authorization, complex programming, and high costs brought about by controlling the state of the PLC by writing corresponding program segments into the operating program inside the PLC, and by configuring the master computer software to control and manage the right of use. Summary of the Invention

[0006] An embodiment of the present invention provides a PLC authorization expiration shutdown system based on a multi-point communication protocol to overcome the above problems or at least partially solve the above problems.

[0007] An embodiment of the present invention provides a PLC authorization expiration shutdown system based on a multi-point communication protocol, including: a start-stop system circuit board, an on-board non-contact CPU card reader, and a non-contact CPU card. Among them,

[0008] The non-contact CPU card is used to store PLC allowed running time data;

[0009] An access coil for sensing the non-contact CPU card is provided on the on-board non-contact CPU card reader. The on-board non-contact CPU card reader is used to obtain the PLC allowed running time data stored in the non-contact CPU card and send the PLC allowed running time data to the start-stop system circuit board;

[0010] The start-stop system circuit board includes an on-board multi-point communication interface, an on-board non-contact CPU card reader interface, and a control circuit for issuing an authorization expiration shutdown command to the target PLC based on the PLC allowed running time data;

[0011] The start-stop system circuit board is connected to the target PLC through the on-board multi-point communication interface, and the start-stop system circuit board is connected to the on-board contactless CPU card reader through the on-board contactless CPU card reader interface.

[0012] Further included is: a contactless CPU card reading and writing host,

[0013] On the contactless CPU card reading and writing host, there is a contactless CPU card upper-level reader and writer for writing the PLC allowed running time data and data permission identifier to the contactless CPU card.

[0014] Among them, the on-board multi-point communication interface is connected to the CPU programming port of the target PLC through a first connecting wire, and the on-board contactless CPU card reader interface is connected to the on-board contactless CPU card reader through a second connecting wire.

[0015] Among them, the start-stop system circuit board further includes: a power-off memory Flash, a random access memory RAM, a power processing unit, and a clock battery, and the power-off storage Flash, random access memory RAM, power processing unit, and clock battery are respectively electrically connected to the control circuit.

[0016] Among them, the control circuit further includes: a clock synchronization unit, a comparison unit, and a control command generation unit. Among them,

[0017] The clock synchronization unit is used to determine the synchronous clock data of the on-board clock data of the start-stop system circuit board and the clock data of the target PLC based on the multi-point communication protocol;

[0018] The comparison unit is used to compare the synchronous clock data with the PLC allowed running time data;

[0019] The control command generation unit is used to generate a control command that conforms to the multi-point communication protocol based on the output result of the comparison unit, and the control command is used to instruct the target PLC to resume operation or enter the stop state.

[0020] The PLC authorization expiration shutdown system based on the multi-point communication protocol provided by the embodiments of the present invention only needs to connect the shutdown system circuit board to the PLC, and the shutdown system circuit board is connected to an on-board non-contact CPU card reader / writer. There is no need to program on the PLC or modify the original program. By using the non-contact CPU card, when the industrial automatic control equipment based on the PLC is not allowed to run, the PLC can be placed in the STOP mode; when the industrial automatic control equipment based on the PLC is allowed to run, the PLC is placed in the RUN mode, and the operator can operate normally, which is simple and convenient. It overcomes a series of problems such as the program being easily tampered with, requiring authorization, complex programming, and high cost brought about by writing corresponding program segments in the running program inside the PLC to control the state of the PLC and realizing the control and management of the right to use by configuring the host computer software. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic structural diagram of the PLC authorization expiration shutdown system based on the multi-point communication protocol provided by the embodiments of the present invention;

[0023] Figure 2 It is a complete schematic structural diagram of the PLC authorization expiration shutdown system based on the multi-point communication protocol provided by the embodiments of the present invention;

[0024] Description of the reference numerals: 1 - target PLC; 2 - CPU programming port; 3 - first connection line; 4 - shutdown system circuit board; 5 - on-board multi-point communication interface; 6 - on-board non-contact CPU card reader / writer interface; 7 - second connection line; 8 - on-board non-contact CPU card reader / writer; 9 - reading / writing coil; 10 - non-contact CPU card; 11 - control circuit; 12 - power-off storage Flash; 13 - random access memory RAM; 14 - power processing unit; 15 - clock battery; 16 - non-contact CPU card upper-level reader / writer; 17 - non-contact CPU card reading / writing host. Detailed Embodiments

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] The present invention aims to provide a PLC authorization expiration shutdown system based on a multi-point communication protocol. Without programming on the PLC or modifying the original program, when the industrial automatic control equipment based on the PLC is not allowed to run, the PLC is placed in the STOP mode; when the industrial automatic control equipment based on the PLC is allowed to run, the PLC is placed in the RUN mode, and the operator can operate normally.

[0027] As Figure 1 shown, it is a schematic structural diagram of a PLC authorization expiration shutdown system based on a multi-point communication protocol provided by an embodiment of the present invention, including: a startup and shutdown system circuit board 4, an on-board non-contact CPU card reader / writer 8, and a non-contact CPU card 10. Among them,

[0028] The non-contact CPU card 10 is used to store PLC allowed running time data;

[0029] Specifically, the non-contact CPU card is also called a smart card. The integrated circuit in the non-contact CPU card is equipped with a microprocessor CPU, a storage unit (including a random access memory RAM, a program memory ROM (FLASH), and a user data memory EEPROM), and a chip operating system COS. The CPU card equipped with COS is equivalent to a microcomputer, which not only has a data storage function, but also has functions such as command processing and data security protection. In terms of security, compared with the non-contact IC card, the non-contact CPU card has an independent CPU processor and a chip operating system, so it can more flexibly support various different application requirements and design a more secure data exchange process. So far, there is no technology or method for cracking and tampering. Therefore, the non-contact CPU card is an extremely secure storage carrier. The embodiment of the present invention uses the non-contact CPU card to store PLC allowed running time data. Among them, the PLC allowed running time data can be understood as the time data allowing the PLC to run, which can be specific to years, months, days, hours, minutes, seconds, or smaller time units.

[0030] An RF CPU card reader / writer 8 on the aircraft is provided with a reading / writing coil 9 for sensing the RF CPU card 10. The RF CPU card reader / writer 8 on the aircraft is used to obtain the PLC allowed running time data stored in the RF CPU card 10 and send the PLC allowed running time data to the start / stop system circuit board 4;

[0031] It can be understood that when the RF CPU card 10 approaches the reading / writing coil 9, the reading / writing coil 9 can sense that a CPU card is approaching. The RF CPU card reader / writer 8 on the aircraft will send a "card approaching" signal to the start / stop system circuit board 4. Then, the start / stop system circuit board 4 issues a card reading command to the RF CPU card reader / writer 8 on the aircraft. After receiving the card reading command, the RF CPU card reader / writer 8 on the aircraft obtains the PLC allowed running time data stored in the RF CPU card 10 and sends the PLC allowed running time data to the start / stop system circuit board 4.

[0032] The start / stop system circuit board 4 includes an on-board multi-point communication interface 5, an RF CPU card reader / writer interface 6 on the aircraft, and a control circuit 11 for issuing an authorization expiration stop command to the target PLC based on the PLC allowed running time data;

[0033] The start / stop system circuit board 4 is connected to the target PLC 1 through the on-board multi-point communication interface 5, and the start / stop system circuit board 4 is connected to the RF CPU card reader / writer 8 on the aircraft through the RF CPU card reader / writer interface 6 on the aircraft.

[0034] Specifically, the on-board multi-point communication interface 5 performs data transmission based on a multi-point communication protocol. The on-board multi-point communication interface 5 can be a serial port supporting the multi-point communication protocol, or other interfaces supporting the multi-point communication protocol. To ensure normal communication between the start / stop system circuit board and the target PLC, the on-board multi-point communication interface 5 usually adopts a relatively high communication rate, such as 187500 bps, etc. It can be understood that the on-board multi-point communication interface 5 is a high-speed communication port supporting the multi-point communication protocol.

[0035] The RF CPU card reader / writer interface 6 on the aircraft can be a common serial port, such as a 485 / 232 interface, or a USB interface, or other communication interfaces.

[0036] The embodiment of the present invention realizes the control of the stop and restart (set STOP, set RUN) of the PLC supporting the multi-point communication protocol without changing the control program inside the PLC.

[0037] The typical multi-point communication protocol is the MPI (Multi Point Interface) protocol. The MPI protocol is a confidential communication protocol developed by Siemens for communication between Siemens PLCs. The MPI protocol is a communication method that can be used when the communication rate requirement is not high and the communication data volume is not large. When using the MPI protocol to access the PLC, it needs to be done after the communication parties have "handshaked".

[0038] Furthermore, the onboard multipoint communication interface 5 is connected to the CPU programming port of the target PLC 1 via a first connection line, and the onboard contactless CPU card reader / writer interface 6 is connected to the onboard contactless CPU card reader / writer 8 via a second connection line.

[0039] It should be noted that the CPU programming port of the PLC can be an RJ45 interface, a DB9 interface or other interfaces, which depends on the device type of the PLC.

[0040] The start-stop system circuit board 4 also includes a control circuit 11, which can be a central processing unit CPU. The control circuit 11 determines whether the running time data of the target PLC 1 reaches the running time data allowed by the PLC based on the running time data allowed by the PLC. If so, after successfully shaking hands with the target PLC, the control circuit 11 sends an authorized expired shutdown command that complies with the communication format of the target PLC to the target PLC 1.

[0041] It can be understood that, according to the characteristics of the equipment supporting the multi-point communication protocol, no matter what state the target PLC 1 is in (RUN or STOP), once powered on, the target PLC 1 will periodically send out handshake request data frames, and the start-stop system circuit board 4 responds to the data frames periodically sent by the target PLC 1, performs mutual confirmation and other interactive processes, and completes the handshake process. The target PLC1 and the start-stop system circuit board 4 can transmit data normally. The target PLC 1 sends data frames to the start-stop system circuit board 4 through the CPU programming port, the first connecting line, and the onboard multi-point communication interface 5; the data frame written to the target PLC 1 is transmitted to the target PLC 1 from the start-stop system circuit board 4, the onboard multi-point communication interface 5, through the first connecting line, and through the CPU programming port.

[0042] After receiving the authorization expired shutdown command issued by the startup and shutdown system circuit board 4, the target PLC 1 automatically enters the STOP state and automatically shuts down. It can only enter the RUN state after the data in the contactless CPU card 10 with startup permission data is swiped next time, and the operator can use the PLC-based industrial automatic control equipment to operate normally, thereby achieving the purpose of PLC authorization expired shutdown based on the multi-point communication protocol.

[0043] The PLC authorization expiration shutdown system based on the multi-point communication protocol provided by the embodiment of the present invention only needs to connect the shutdown system circuit board to the PLC, and the shutdown system circuit board is connected to an on-board non-contact CPU card reader / writer. There is no need to program on the PLC or modify the original program. By using the non-contact CPU card, when the industrial automatic control equipment based on the PLC is not allowed to run, the PLC can be placed in the STOP mode; when the industrial automatic control equipment based on the PLC is allowed to run, the PLC is placed in the RUN mode, and the operator can operate normally, which is simple and convenient. It overcomes a series of problems such as the program being easily tampered with, requiring authorization, complex programming, and high cost caused by writing corresponding program segments in the running program inside the PLC to control the state of the PLC and implementing the control and management of the usage right through configuring the host computer software.

[0044] Based on the content of the above embodiment, the PLC authorization expiration shutdown system based on the multi-point communication protocol further includes: a non-contact CPU card reading / writing host,

[0045] A non-contact CPU card upper-level reader / writer for writing PLC allowed running time data and data permission identifier to the non-contact CPU card is provided on the non-contact CPU card reading / writing host.

[0046] Specifically, the embodiment of the present invention also configures a non-contact CPU card reading / writing host, and a non-contact CPU card upper-level reader / writer is also provided on the non-contact CPU card reading / writing host, so as to realize writing PLC allowed running time data and data permission identifier to the non-contact CPU card. The data permission identifier is used to indicate that the PLC allowed running time data stored in the non-contact CPU card 10 can be transmitted to the shutdown system circuit board 4 supporting the target PLC.

[0047] Based on the content of the above embodiment, the shutdown system circuit board further includes: a power-off memory Flash, a random access memory RAM, a power processing unit, and a clock battery. The Flash, RAM, power processing unit, and clock battery are respectively electrically connected to the control circuit.

[0048] Based on the content of the above embodiment, the control circuit further includes: a clock synchronization unit, a comparison unit, and a control command generation unit. Among them,

[0049] The clock synchronization unit is used to determine the synchronous clock data of the on-board clock data of the shutdown system circuit board and the clock data of the target PLC based on the multi-point communication protocol;

[0050] The comparison unit is used to compare the synchronous clock data with the PLC allowed running time data;

[0051] The control command generation unit is configured to generate a control command conforming to the multi-point communication protocol based on the output result of the comparison unit, and the control command is used to instruct the target PLC to resume operation or enter a shutdown state.

[0052] Specifically, since the clock on the industrial-grade circuit board will have a time difference from the standard clock reference after long-term operation (such as one day, one week, etc.), clocks are set on both the power-on / off system circuit board and the target PLC, and these two clocks are bound to be slightly different. Therefore, it is necessary to synchronize the on-board clock data of the power-on / off system circuit board with the clock data of the target PLC to generate synchronized clock data.

[0053] The control circuit includes: a clock synchronization unit, a comparison unit, and a control command generation unit. Among them, the clock synchronization unit is configured to determine the synchronized clock data of the on-board clock data of the power-on / off system circuit board and the clock data of the target PLC based on the multi-point communication protocol at every preset time interval.

[0054] When the synchronized clock data of the on-board clock data of the power-on / off system circuit board and the clock data of the target PLC is earlier than the PLC allowed operation time data, the target PLC is authorized to run; when the synchronized clock data of the on-board clock data of the power-on / off system circuit board and the clock data of the target PLC reaches the PLC allowed operation time data, it indicates that the authorization of the target PLC has expired and the target PLC needs to enter a shutdown state. Therefore, the comparison unit is used to compare the size of the synchronized clock data with the PLC allowed operation time data to determine whether the synchronized clock data reaches the PLC allowed operation time data, and the control command generation unit issues a control command conforming to the multi-point communication protocol based on the output result of the comparison unit to instruct the target PLC to resume operation or enter a shutdown state.

[0055] Such as Figure 2As shown in the figure, it is a complete structural schematic diagram of the PLC authorization expiration shutdown system provided by the embodiment of the present invention. In the embodiment of the present invention, the target PLC is a Siemens PLC. On the CPU programming port 2 of the target PLC 1, the on-board multi-point communication interface 5 of the startup and shutdown system circuit board 4 is connected through the first connection line 3. The on-board non-contact CPU card reader / writer interface 6 of the startup and shutdown system circuit board 4 is connected to the on-board non-contact CPU card reader / writer 8 through the second connection line 7. A reading and writing coil 9 is installed on the on-board non-contact CPU card reader / writer 8. In addition, a control circuit 11, a power-off memory Flash 12, a random access memory RAM 13, a power processing unit 14, and a clock battery 15 are also provided on the startup and shutdown system circuit board 4. Among them, the power-off memory Flash 12, the random access memory RAM 13, the power processing unit 14, and the clock battery 15 are all electrically connected to the control circuit. In addition, a non-contact CPU card reading / writing host 17 is configured, and a non-contact CPU card upper-level reading / writer 16 is also included on the non-contact CPU card reading / writing host 17.

[0056] The working principle of the PLC authorization expiration shutdown system provided by the embodiment of the present invention is as follows:

[0057] In the initial state, there is no PLC allowed running time data inside the startup and shutdown system circuit board 4. During the interaction process of responding to the data frames periodically sent by the target PLC 1 and performing mutual confirmation, after the handshake process is completed, an initial shutdown STOP instruction conforming to the communication format of the target PLC is sent, and through the on-board multi-point communication interface 5, the first connection line 3, and the CPU programming port 2, it is sent to the target PLC 1. If the target PLC 1 determines that the received information conforms to the STOP instruction format, the target PLC 1 is automatically set to the STOP state. At this time, the PLC no longer responds to the instructions of its external IO points, that is, it does not respond to any instructions of the operator. In the initial state, unauthorized operators cannot start the machine and wait for card swiping.

[0058] When the contactless CPU card 10 approaches the reading and writing coil 9 of the on-board contactless CPU card reader / writer 8, the reading and writing coil 9 senses the approach of the contactless CPU card 10. The on-board contactless CPU card reader / writer 8 sends a "card approaching" signal through the second connecting wire 7 and the on-board contactless CPU card reader / writer interface 6 to the start / stop system circuit board 4. The start / stop system circuit board 4 issues a card reading command to the on-board contactless CPU card reader / writer 8. The on-board contactless CPU card reader / writer 8 reads the PLC allowed running time data in the contactless CPU card 10 and sends it to the start / stop system circuit board 4 through the second connecting wire 7 and the on-board contactless CPU card reader / writer interface 6. The start / stop system circuit board 4 determines whether the contactless CPU card 10 has the power-on permission. When it is determined that the contactless CPU card 10 has the power-on permission, a resume RUN instruction conforming to the target PLC communication format is issued and sent to the target PLC 1 through the on-board multi-point communication interface 5, the first connecting wire 3, and the CPU programming port 2. At this time, the target PLC 1 is set to the RUN state and enters the normal state of waiting for the operator to operate. It is realized that after swiping the card with the authorized card, normal operation can be carried out.

[0059] As time goes by, when the stop time point corresponding to the PLC allowed running time arrives, the start / stop system circuit board 4 issues a stop STOP instruction conforming to the multi-point communication protocol and sends it to the target PLC1 through the first connecting wire 3 and the CPU programming port 2. The target PLC 1 determines that the received information conforms to the stop STOP instruction format, and then the target PLC 1 is automatically set to the STOP state. At this time, the PLC no longer responds to the instructions of its external IO points, that is, it does not respond to any instructions of the operator. It is realized that in the state where the authorized use arrives, the unauthorized operator cannot power on and waits for swiping the card to enter the next round of operation.

[0060] When actually using the contactless CPU card, it is necessary to initialize the contactless CPU card 10 and set the time data allowed for the target PLC to run. The solution is as follows: First, through the contactless CPU card reading and writing host 17 and the contactless CPU card upper-level reading and writing device 16, the contactless CPU card 10 is emptied; second, through the contactless CPU card reading and writing host 17 and the contactless CPU card upper-level reading and writing device 16, the time data allowed for the target PLC to run, that is, the PLC allowed running time data, is written into the contactless CPU card 10, and a data permission identifier is written. This data permission identifier is used to indicate that the PLC allowed running time data stored in the contactless CPU card 10 can be transmitted to the start / stop system circuit board 4 supporting the target PLC1.

[0061] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

[0062] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PLC authorization expiration shutdown system based on a multi-point communication protocol, characterized in that Including: Startup and shutdown system circuit board, on-board contactless CPU card reader / writer, and contactless CPU card. Among them, The contactless CPU card is used to store PLC allowed running time data. The contactless CPU card includes a microprocessor CPU, a storage unit, and a chip operating system COS; On the on-board contactless CPU card reader / writer, there is a read / write coil for sensing the contactless CPU card. The on-board contactless CPU card reader / writer is used to obtain the PLC allowed running time data stored in the contactless CPU card and send the PLC allowed running time data to the startup and shutdown system circuit board; The startup and shutdown system circuit board includes an on-board multi-point communication interface, an on-board contactless CPU card reader / writer interface, and a control circuit for sending an authorization expiration shutdown command to the target PLC based on the PLC allowed running time data. The on-board multi-point communication interface is a high-speed communication port supporting the multi-point communication protocol; The startup and shutdown system circuit board is connected to the target PLC through the on-board multi-point communication interface, and the startup and shutdown system circuit board is connected to the on-board contactless CPU card reader / writer through the on-board contactless CPU card reader / writer interface; The control circuit further includes: a clock synchronization unit, a comparison unit, and a control command generation unit. Among them, The clock synchronization unit is used to determine the synchronous clock data of the on-board clock data of the startup and shutdown system circuit board and the clock data of the target PLC based on the multi-point communication protocol; The comparison unit is used to compare the synchronous clock data with the PLC allowed running time data; The control command generation unit is used to generate a control command conforming to the multi-point communication protocol based on the output result of the comparison unit. The control command is used to instruct the target PLC to resume operation or enter the shutdown state; The on-board multi-point communication interface is connected to the CPU programming port of the target PLC through a first connection line, and the on-board contactless CPU card reader / writer interface is connected to the on-board contactless CPU card reader / writer through a second connection line; The startup and shutdown system circuit board further includes: a power-off memory Flash, a random access memory RAM, a power processing unit, and a clock battery. The power-off storage Flash, random access memory RAM, power processing unit, and clock battery are respectively electrically connected to the control circuit.

2. The PLC authorization expiration shutdown system based on the multi-point communication protocol according to claim 1, characterized in that Also including: Contactless CPU card reader / writer host, On the contactless CPU card reader / writer host, there is a contactless CPU card upper-level reader / writer for writing the PLC allowed running time data and data permission identifier to the contactless CPU card.

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