JP2013131043A - Programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that if data of a flag storage part is changed (altered) from an external device, protection of a sequence program does not function.SOLUTION: In a peripheral device connection management memory, a serial number of programming tool which can be on-line connected to PCL is registered so that only the programming tool owned by a sequence program creator (original owner) can read/write a sequence program.

Description

  The present invention relates to a programmable controller that controls a device using a program, and more particularly to information leakage security that makes it impossible for a third party to view a user program created by a user.

The user program is a property of the user created by the user making full use of time, intelligence, and cost. Since the programmable controller does not operate without the user program, the user program is always stored in the programmable controller.
FIG. 4 shows a block diagram of a conventional programmable controller.
In FIG. 4, the programmable controller 60 includes a microcomputer 61 that performs arithmetic processing, a memory 62 that stores a sequence program and data, and the memory 62 stores a system program.
The system includes a system memory 63 and a user memory 64 that stores a user program 65, an input / output I / F (interface) 66 for inputting / outputting signals to / from the outside, a personal computer, another programmable controller, a control device, etc. A communication I / F (interface) 67 for exchanging data is connected to a bus line 68 for information communication.
In such a programmable controller system, a general user can easily obtain a third party without taking a means for prohibiting reading of the user program from the outside.
In the conventional system block shown in FIG. 4, a security function using a password is used. The security function using the password has a problem that once the password is leaked, the security is easily broken.
This is because a user who sets a password uses easy-to-remember numbers such as a birthday for the user or an anniversary of the user. Also, even if you set a password that is difficult for someone else to guess, you might forget the password you set, or leave it on paper so that you don't forget it. And could easily leak.

Further, according to Patent Document 1 (Japanese Patent Laid-Open No. 2006-331130), the main processing unit 10 controls equipment according to a sequence program stored in the program memory 11. In addition, a service interface 14 for connecting an external device capable of communicating with the main processing unit 10 is provided. The main processing unit 10 includes a read prohibition processing unit 22 that prohibits reading of a sequence program stored in the program memory 11 from the service interface 14 to an external device.
Accordingly, it is disclosed that reading of the sequence program from the service interface 14 to the external device can be prohibited, so that it is possible to prevent the know-how of the sequence program from being known to others or the sequence program from being promoted. ing.

JP 2006-331130 A

Patent Document 1 discloses a mechanism of a programmable controller that protects a sequence program (same as a user program).
That is, “the main processing unit 10 is provided with a flag storage unit 10a for storing a read prohibition flag for switching between valid and invalid of the read prohibition processing unit 22. The read prohibition processing unit 22 sets a read prohibition flag. If the read prohibition flag is not set, the read prohibition processing unit 22 is invalid.The invalidity of the read prohibition processing unit 22 means that a “program read” instruction is accepted.
When the read prohibition flag is set and the read prohibition processing unit 22 is enabled, the “program read” instruction is ignored.
The read prohibition flag is not set in the initial state, but once the read prohibition flag is set, the read prohibition flag cannot be reset and returned to the original state thereafter.
In other words, the read prohibition processing unit 22 is initially in an invalid state, but if the read prohibition flag is set and the read prohibition processing unit 22 is switched to a valid state, the read prohibition processing unit 22 is invalidated thereafter. Cannot be read and reading of the program is prohibited. In other words, the read prohibition flag can be irreversibly changed from a state where it is not set to a state where it is set.

  In the above configuration, if the data in the flag storage unit is changed (tampered) from an external device, the protection of the sequence program may not function.

  An object of the present invention is to solve the above-described problems, and only the sequence program creator (original owner) can read / write the sequence program, and whether or not the data memory can be read / written. Also, it is an object of the present invention to provide a programmable controller having these configurations so that only the creator (original owner) of the sequence program can make settings.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present invention relates to an MPU that performs calculation of a sequence program and communication processing with a programming tool that is an application of a personal computer connected via a peripheral device interface unit, and a rewritable sequence for storing the sequence program created by a user A program memory; and a peripheral device connection permission management memory for storing connection permission management data of peripheral devices connected by the peripheral device interface unit or the external device connection module. The peripheral device connection management memory is online with the programmable controller. By registering the serial number of the programming tool that can be connected, only the programming tool (original owner) owned by the sequence program creator can read / write the sequence program. Characterized in that it is possible to perform the write.
In the above programmable controller, programming information other than the serial number of the programming tool and MAC address information of the Ethernet (registered trademark) port as online connection management target information as online connection permission information in the peripheral device connection management memory. Features.
In the above programmable controller, when an online connection is requested from the programming tool with a different serial number that is not registered in the peripheral device connection permission management memory, the information "Do not allow online connection" is displayed. It is characterized by that.
Further, in the programmable controller, information for restricting a sequence program read / write operation using a memory unit connected from the programming tool to the peripheral device connection permission management memory via an external memory unit interface (memory unit) (Operation availability information) can be set, and the operation as set is performed.
In the programmable controller described above, the operation permission (restriction) can be set for each read / write operation, not the collective restriction, in the restriction of the read / write operation of the sequence program to the memory unit. It is characterized by performing a street operation.

According to the present invention, it is possible to limit the person who performs the read / write processing of the sequence program, so that the sequence program can be protected without being known or stolen by a third party. It becomes possible.
Similarly, online connection is possible and devices for data communication can be set.

The block diagram of the programmable controller which is one Example of this invention is shown. The programming tool registration processing flowchart is shown. The flowchart of a connection process from a programming tool is shown. The block diagram of the conventional programmable controller is shown.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Example 1)
FIG. 1 is a system block diagram of a programmable controller according to an embodiment of the present invention.
In FIG. 1, 1 is a CPU module of a programmable controller, 2 is a programming tool, 3 is an external input module, 4 is an external output module, 10 is an MPU, 11 is a peripheral device interface, 12 is a system program memory, and 13 is a sequence program memory. , 14 is an internal data memory, 15 is an external bus interface, 16 is an external memory unit interface, 17 is a memory unit, 18 is an upper host such as a personal computer, 19 is an external device connection module, 20 is an HMI (Human Machine Interface), 21 Is a peripheral device connection permission management memory.

In FIG. 1, the CPU module 1 of the programmable controller includes an MPU 10 that performs communication processing with a programming tool 2 that is a personal computer application connected via an arithmetic expression of a sequence program and a peripheral device interface unit 11, and contents controlled by the MPU 10. A non-volatile system program memory 12 storing the procedure, a rewritable sequence program 13 for storing a sequence program created by the user, an internal data memory 14 for storing the calculation result of the sequence program by the MPU 10, and peripherals Peripheral device connection permission management memory 21 for storing connection permission management data of connection devices of peripheral devices connected to the device interface unit 11 or the external device connection module 19, and an external bus for adding input / output ports An interface 15 is provided.
Connected to the external bus interface 15 are an input module 3 for capturing an input signal from an external device, an output module 4 for outputting a calculation result to an output signal to the external device, and an external device connection module 19. And
The external output module 3 inputs input signals such as sensors and switches, and the external output module 4 outputs output signals to lamps, actuators, and the like.
The external device connection module 19 has a function equivalent to that of the peripheral device interface unit 11, and is connected to the programming tool 2, the HMI (Human Machine Interface) 20, the upper host (such as a personal computer) 18, and device devices such as an inverter. Data communication can be performed.
The peripheral device 11 is connected to the programming tool 2, the HMI 20, and the upper host (such as a personal computer) 20 to perform data communication.
In the programming controller in the initial state, since the peripheral device permission management memory 21 is not registered, nothing is restricted and the peripheral device (programming tool 2, HMI 20) and the device device are the peripheral device interface unit 11 or the external device. The MPU 10 can be connected via the device connection module 19.
In such a state, it is possible to freely read / write from / to the sequence program memory 13 created by the user from the programming tool 2.
The user performs registration processing of peripheral devices connectable from the programming tool 2 in order to protect the sequence program (impossible to read / write).

FIG. 2 is a flowchart showing an embodiment of a connectable programming tool registration process.
First, the programming tool 2 is connected online to the programmable controller, and peripheral device registration is set (step 31). When the registration work is performed, the programming tool transmits information on its own serial number to the MPU 10 (step 32). The MPU 10 registers a serial number as information of the programming tool 2 that can be connected to the peripheral device connection permission management eye memory 21 based on the information (step 33).
Then, the completion of registration of the serial number is displayed (step 34), and the process is terminated (step 35).

Next, FIG. 3 shows an example of processing in the case of online connection from the programming tool 2 in a state where information is registered in the peripheral device connection permission management memory 21.
In the flowchart of FIG. 3, first, a permission command is transmitted from the programming tool 2 for online connection to the MPU 10 (step 41).
The MPU 10 receives the permission command and confirms the information in the peripheral device connection permission management memory 21 (step 42).
Then, the MPU 10 is for the programming tool 2. It is determined whether serial number information is registered (step 43).
If the serial number information is not registered, online connection is permitted and the program is connected to the programming tool, and the sequence program can be read / written (step 49).
If the serial number information has been registered, the programming tool 2 is requested to transmit the serial number information (step 44).
The requested programming tool 2 transmits its own serial number to the MPU 10 (step 45).
Next, the MPU 10 receives the serial number transmitted from the programming tool 2 (step 46), and checks whether it is the same as the serial number registered in the peripheral device connection permission management memory 21 (step 47).
Then, it is determined whether the serial number transmitted from the programming tool 2 matches the serial number registered in the peripheral device connection permission management memory 21 (step 48).
If the serial numbers match, online connection is permitted and the program is connected to the programming tool, so that the sequence program can be read / written (step 49).
When the serial number registered in the peripheral device connection permission management memory 21 and the serial number transmitted from the programming tool 2 are different (verification mismatch), the MPU 10 executes an operation that does not permit online connection with the programming tool 2.
That is, the MPU 10 transmits an online connection refusal command (step 50), and the connection with the programming tool 2 is disabled (step 49).
The programming tool 2 displays “Online connection is not permitted”.

Here, the serial number will be described.
A serial number is a "production number" that is uniformly assigned to industrial products that are manufactured in large quantities, such as electrical appliances, cameras, and automobiles. In principle, products that have the same serial number are the same. It does not exist if it is a product of a variety. Therefore, when a problem occurs, it may be used for tracking surveys by manufacturers and maintenance inquiries to purchasers.
In computer software, it is a number for managing individual products in the above sense.
Generally, a serial number is attached to the cover of a product such as a ladder programming software of a programmable controller, and if there is a problem when the serial number and customer are registered for the purchased customer. This information may be used when maintenance is needed.
Recently, in order to prevent piracy and unauthorized use, software and shareware sold in packages often require a serial number to be input after installation. In this case, some serial numbers are encrypted (checksum etc.) in consideration of theft.
This completes the description of the embodiment using the serial number of the programming tool 2.
(Example 2)
Next, another embodiment will be described.

In the second embodiment, the MAC address information of the Ethernet (registered trademark) port of the programming tool 2 is used.
The MAC address is a physical address uniquely assigned to hardware of a network device such as a LAN card set to identify each node on the network. In the OSI reference model, the second layer (data Link layer) address.
(Example 3)
Next, a case where the memory unit 17 shown in FIG. 1 is used as a method for reading / writing a sequence program to / from the sequence program memory 13 will be described.
In this case, since the programming tool 2 is not used, the sequence program cannot be completely protected only by this method.
A method for protecting the sequence program when the memory unit 17 is used will be described below.

The user sets memory unit operation availability information from the programming tool 2 for controlling reading / writing of the sequence program using the memory unit 17 to the programmable controller. The MPU 10 registers the memory unit operation enable / disable information in the peripheral device connection permission flag memory 21 based on the memory unit operation enable / disable information.
The MPU 10 executes a sequence program read / write operation between the memory unit 17 and the sequence program memory 13 based on the memory unit operation availability information registered in the peripheral device connection permission management memory 21.
When the memory unit operation enable / disable information in the peripheral device connection permission management memory 21 is set to disable the memory unit operation, the sequence program read / write operation to the memory unit 17 cannot be executed.

  With the configuration of the third embodiment described above, it is possible to realize a programmable controller that allows only a programming tool (original owner) owned by the sequence program creator to read / write the sequence program.

The internal data memory 14 may store data important for sequence control, but these data can be read / written by data communication from the host 18 and the HMI 19.
For online connection with the host 18 and the HMI 19, the MAC address information permitting online connection can be set from the programming tool 2 to the peripheral device connection management memory 21, and only the host 18 or HMI 19 having the set MAC address is connected online. This makes it possible to realize a programmable controller with strong security.

DESCRIPTION OF SYMBOLS 1 ... CPU module 2 ... Programming tool 3 ... External input module 4 ... External output module 10 ... MPU 11 ... Peripheral device interface 12 ... System program memory 13 ... Sequence program memory 14 ... Internal data memory 15 ... External bus interface 16 ... External memory Interface 17 ... Memory unit 21 ... Peripheral device connection permission management memory

Claims (5)

An MPU that performs processing of a sequence program and performs communication processing with a programming tool that is an application of a personal computer connected via a peripheral device interface unit;
A rewritable sequence program memory for storing the sequence program created by the user;
A peripheral device connection permission management memory for storing connection permission management data of peripheral devices connected by the peripheral device interface unit or the external device connection module;
The peripheral device connection management memory registers the serial number of the programming tool that can be connected to the programmable controller online, so that only the programming tool (original owner) owned by the sequence program creator can read / write the sequence program. A programmable controller characterized in that The programmable controller according to claim 1,
A programmable controller in which the peripheral device connection management memory uses as the online connection management information information a programming tool other than the serial number of the programming tool and MAC address information of the Ethernet (registered trademark) port as online connection permission information. The programmable controller according to claim 1,
A programmable controller, wherein when online connection is requested from the programming tool having a different serial number that is not registered in the peripheral device connection permission management memory, information indicating “online connection is not permitted” is displayed. The programmable controller according to claim 1 or 2,
Information (memory unit operation availability information) for restricting the read / write operation of the sequence program using the memory unit connected via the external memory unit interface can be set in the peripheral device connection permission management memory from the programming tool, A programmable controller characterized in that it operates as set. The programmable controller according to claim 4,
The restriction of the read / write operation of the sequence program to the memory unit is not limited at once, but operation permission (restriction) can be set for each read / write operation, and the operation as set is performed. Programmable controller.

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