JP2010146195A - Programmable controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a programmable controller having a security function to reduce the load on a system. <P>SOLUTION: User management information 1 for authenticating a user is separated from access control information 2 for controlling access to files in the programmable controller, and user authentication and control of access to the files are separated into two steps to reduce the load on the system. Further, the access control information 2 is set for each file, thereby suppressing an increase in the amount of information due to addition of files to be access-controlled and reducing the load on the system. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a programmable controller that performs sequence control of a device to be controlled, and more particularly to a programmable controller equipped with a security function.

  Conventionally, what is described below is disclosed as a programmable controller equipped with a security function.

  That is, after a memory card storing a user authentication table storing user information including a user name, a password, and an access level is mounted on a programmable controller, user information including a user name and a password is obtained from a tool accessible to the programmable controller. The described login request command is transmitted to the programmable controller. Then, when the user name and password described in the login request command match the user name and password in the user authentication table of the memory card, access to the programmable controller by a tool that can access the programmable controller is performed. to approve. Furthermore, the programmable controller can be accessed within the permitted range of the access level stored in the user authentication table (see, for example, Patent Document 1). In addition, the definition of the access level in Patent Document 1 is information in which operation (reading, writing, execution permission) is set for each area of each file in the programmable controller.

JP 2003-167606 A

  In the conventional technique, information for authenticating a user and information for controlling access to a file in the programmable controller are collectively managed in one table, and user authentication and control of access to the file are controlled by the table. The system is overloaded. Furthermore, since this information is set for each user, for example, with the addition of a file whose access is to be controlled by the user, it is necessary to set whether or not the added file can be accessed for all registered users. The amount of information becomes enormous. This also contributes to the load on the system.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a programmable controller equipped with a security function capable of reducing the load on the system.

  In order to solve the above-described problems and achieve the object, the programmable controller according to the present invention can be accessed only by a user who is permitted to access from the outside, and accesses at least a part of the files existing inside. In a programmable controller in which control is performed, user management information used as information for authenticating a user, including an access level that is a user name, a password, and an access authority level, and access to the file for each access level Access control information, which is information defining access permission for the access operation to the file, includes a stored private memory, and the user accesses the user who tries to access the file to be accessed. Username and password entered at the time If the user name and password included in the user management information match and the user is authenticated, and the access control information for the file is stored in the private memory, the user management information According to the access level set by the user, access to the file is permitted within a range permitted to be set by the access control information.

  According to the present invention, the user management information used as information for authenticating the user, including the access level that is the user name, password, and access authority level, and whether or not the file can be accessed for each access level Since the access control information, which is the information defined for the access operation to the file, is divided and managed, the load on the system can be reduced.

  Embodiments of a programmable controller according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an overall configuration of a programmable controller according to the present embodiment. As will be described below, the programmable controller 101 of this embodiment has a security function for controlling access to files from the outside. Here, the security function refers to, for example, a function that prevents a malicious user from falsifying and stealing a file, and modification due to a user malfunction. FIG. 6 is a diagram showing the contents stored in the system memory.

  As shown in FIG. 1, the programmable controller 101 includes an MPU 102, a program memory 103, a system memory 104, a data memory 105, and a communication driver 106, and is further connected to an external tool 107.

  In FIG. 1, a program memory 103 is a memory that stores information for the programmable controller 101 to calculate such as a sequence program. The MPU 102 functions as a control unit that controls the overall operation of the programmable controller 101. The data memory 105 is a memory in which environment setting data necessary for controlling the programmable controller 101 is stored. The communication driver 106 is a driver that enables communication between the programmable controller 101 and the tool 107. The tool 107 is a tool that can access the programmable controller 101. The system memory 104 is a private memory, and as shown in FIG. 6, user management information 1 that is information for authenticating a user, and whether or not each file can be accessed (for example, read, written, displayed) is an access level. It is a memory in which access control information 2 that is information defined for each and a login user information table 3 that is information of a user who has logged into the programmable controller 101 are stored.

  FIG. 2 is a diagram showing the configuration of the user management information 1 in the present embodiment. The user management information 1 and the login user information table 3 store user names, passwords, and access levels. The access level is expressed in five levels, for example, Administrators, Developers (Level 3), Developers 2 (Level 2), Developers 1 (Level 1), and Users, and each user who accesses the programmable controller 101 has the authority to access the files inside the programmable controller 101. Assign. The configuration of the login user information table 3 is the same as that of the user management information 1.

  That is, in the user management information 1 shown in FIG. 2, the password “Admini_MAN” and the access level “Administrators” are stored in correspondence with the user name “SATO”. Similarly, the password “User_MAN” and the access level “Users” are stored corresponding to the user name “SUZUKI”, and the password “Develop_MAN” and “Developers (Level3)” are stored corresponding to the user name “TAKAHASI”. Is done. The configuration of the login user information table 3 is the same as the user management information 1 shown in FIG. 2, but information is managed only for users who are logged in to the programmable controller 101.

  FIG. 3 is a diagram showing a configuration of the access control information 2 in the present embodiment. The access control information 2 stores information on the access level and whether or not access (reading, writing, and display) to a file in the programmable controller 101 is possible. The access control information 2 is set for each file in the programmable controller 101, for example. A user who is authenticated by the programmable controller 101 can access according to the access control information 2 set for each file in the programmable controller 101. Here, the access according to the access control information 2 set for the file to be accessed is an access that matches the “access level” set in the user management information 1 of the user authenticated by the programmable controller 101. This means access in accordance with “accessibility of file” set in “access level” of management information 2.

  That is, in the access control information 2 of FIG. 3, the user corresponding to the access level “Administrators” indicates that all operations of “read”, “write”, and “display” are set to “permitted”. Yes. Similarly, the user corresponding to the access level “Developers (Level 3)” also indicates that all operations are set to “permitted”, and corresponds to the access levels “Developers (Level 2)” and “Developers (Level 1)”. The user indicates that the “read” and “display” operations are set to “permitted” and the “write” operation is set to “prohibited”, and the user corresponding to the access level “Users” This indicates that the “write” operation is set to “permitted” only for the “prohibited” and “display” operations.

  Next, the operation of the present embodiment will be described with reference to FIG. A user accessing the programmable controller 101 can access the program memory 103 and the data memory 105 from the tool 107 via the communication driver 106.

  Receiving the access request from the user, the programmable controller 101 transmits a login request request for requesting the user to re-enter the user name and password to the tool 107 that is the activation source in order to authenticate the user.

  Next, the tool 107 that has received the login request request from the programmable controller 101 displays a login screen and requests the user accessing the programmable controller 101 to input a user name and password.

  When the user inputs the user name and password, the programmable controller 101 compares the user name and password in the user management information 1 stored in the system memory 104 with the input user name and password. If the comparison results match, the user name, password, and access level in the user management information 1 corresponding to the accessing user are copied to the login user information table 3 in the system memory 104, and access is permitted. If the comparison results do not match, access is prohibited and a login request is sent again to the tool 107 via the communication driver 106. As described above, since the control process of the programmable controller 101 is realized by the MPU 102, specifically, the comparison process and the like are performed by the MPU 102, and so on.

  The programmable controller 101 deletes information corresponding to the user in the login user information table when the logged-in user performs a logoff operation or when there is no access from the logged-in user for a certain period of time. .

  When the programmable controller 101 authenticates the accessing user, the programmable controller 101 accesses according to the access control information 2 in the system memory 104 set for the file to be accessed in the program memory 103 or the file to be accessed in the data memory 105. Allow.

  That is, when the programmable controller 101 authenticates the accessing user, the programmable controller 101 refers to the access control information in the system memory 104 set for the file in the program memory 103 to be accessed or the file in the data memory 105. The access corresponding to the access level set in the user management information 1 is permitted.

  For example, the user “UserA” who is authenticated by the programmable controller 101 is set to the access level “Developers (Level2)” in the user management information 1 and the access set to the “file A” to be accessed is set. In the control information 2, if the access operation of “Developers (Level 2)” is set to prohibit only “write” (FIG. 3), the programmable controller 101 performs “read” as access to “file A” of “UserA”. Only “display” is allowed, and “write” is prohibited.

  FIG. 4 is a flowchart showing the operation of the programmable controller 101 until the programmable controller 101 authenticates a user who has accessed through the tool 107 and permits access to the file to be accessed.

  As shown in FIG. 4, first, when the programmable controller 101 receives a login request command from the tool 107 via the communication driver 106 (S1), the user name in the user management information 1 stored in the system memory 104 is displayed. Then, it is confirmed whether there is a password that matches the user name and password entered by the user (S2).

  If there is no match in S2 (S2, No), a login request is sent to the tool 107 again (S3), and the user is requested to re-enter the user name and password.

  If there is a match in S2 (S2, Yes), the information (user name, password, and access level) in the user management information 1 corresponding to the user is copied to the login user information table 3 (S4), then Then, it is checked whether or not the access control information 2 is set for the file to be accessed with reference to the system memory 104 (S5).

  If the access control information 2 is set for the file to be accessed (S5, Yes), the access control information 2 that has been set is referred to and the access level that matches the access level set for the user is set. On the other hand, access by the user is permitted within the permitted range (S6).

  If the access control information 2 is not set for the file to be accessed (S5, No), access to the file is permitted without restriction regardless of the access level set by the user (S7). ).

  According to the present embodiment, information that is conventionally managed in a lump (that is, information for authenticating a user and controlling access to a file) is divided into user management information 1 and access control information 2. Thus, there is an effect of reducing the load on the system.

  Furthermore, by setting the access control information 2 for each file, it is not necessary to set whether to access the added file for the number of registered users with the addition of the file whose access is to be controlled. Therefore, the load on the system can be further reduced.

  For example, as in Patent Document 1, a programmable controller equipped with a conventional mechanism for authenticating a user collectively manages information for authenticating the user and information for controlling access to a file to be accessed. Since a series of processes from authenticating a user to accessing a file to be accessed in the programmable controller is realized with a single table, a heavy load is imposed on the system. In addition, by setting the information for controlling access to the file for each user, it is necessary to set whether to access the added file for all registered users with the addition of the file whose access is to be controlled. As the amount of information increases, there is a greater load on the system.

  In the present embodiment, the information for authenticating the user, which has been managed collectively in the past, and the information for controlling the access to the file in the programmable controller are separated, and the user authentication and the control of the access to the file are performed in two. By dividing into stages, the load on the system is reduced. Furthermore, by setting information for controlling access to files for each file, the increase in the amount of information associated with the addition of the file whose access is to be controlled can be suppressed, so the load on the system can be further reduced. it can.

  Note that the access level definition in Patent Document 1 is different from the access level definition in the present embodiment. The definition of the access level in Patent Document 1 is information that sets whether or not an operation (reading, writing, execution permission) is permitted for each area of each file in the programmable controller. On the other hand, the definition of the access level in the present embodiment is the type of the level of operation authority given to the user who accesses the programmable controller.

Embodiment 2. FIG.
Because the administrator forgets the password, the security of the programmable controller may not work. As a recovery means when the administrator forgets his / her password, there is a means for acquiring the password by inquiring the manufacturer. However, in this case, although the manufacturer can determine the purchaser, there is a problem that it cannot be determined that the purchaser is an administrator of the programmable controller.

  As another recovery means, there is a means for obtaining a password by presetting an answer that is difficult to forget and its question, answering the question, and answering the question correctly. However, there is a problem that there is no recovery means in the event that an answer to a preset question is forgotten.

  In the present embodiment, a programmable controller that can recover the security function without inquiring the manufacturer for the password even when the administrator forgets his / her password will be described. Note that the programmable controller according to the present embodiment includes the configuration described in the first embodiment (see FIGS. 1 and 6).

  An administrator who has forgotten his password can issue an initialization password command to the programmable controller 101 of FIG. When the programmable controller 101 receives the initialization password command, the programmable controller 101 refers to the login user information table 3 in the system memory 104 to check whether or not there is a logged-in user. It is confirmed whether the initialization password in the system memory 104 matches the initialization password input by the administrator when accessing the programmable controller 101. If the passwords match, the programmable controller 101 deletes the user management information 1, the access control information 2, the login user information table 3 in the system memory 104, and all the data in the program memory 103 and the data memory 105.

  FIG. 5 shows that when the administrator forgets his / her password, the programmable controller 101 controls the security information (user management information 1, access control information 2, and login user information table 3), the program memory 103, and the data memory 105. It is a flowchart which shows the process order which deletes all the internal data.

  When the programmable controller 101 receives an initialization password command from the tool 107 via the communication driver 106 (S20), a login user information table in the system memory 104 indicates whether or not there is a user currently logged in to the programmable controller 101. 3 to confirm (S21).

  When there is a logged-in user (S21, Yes), that is, when a user is registered in the logged-in user information table 3, the programmable controller 101 transmits an initialization impossible message to the tool 107 (S22).

  When there is no logged-in user (S21, No), that is, when no user is registered in the login user information table 3, the initialization password in the received initialization password command and the system memory 104 are stored in advance. The initialization password that has been set is compared to check whether they match (S23).

  When the initialization passwords match (S23, Yes), the user management information 1, the access control information 2, and the login user information table 3 stored in the system memory 104 are deleted, and the program memory 103 and the data memory 105 are deleted. Delete all the data stored in (S24).

  If the initialization passwords do not match (S23, No), an initialization impossible message is transmitted to the tool 107. The initialization password refers to a password that is uniquely set in advance for returning the programmable controller 101 to the factory-shipped state.

  As described above, the administrator who accesses the programmable controller 101 executes the initialization password command and returns the programmable controller 101 to the factory default state, so that even if the administrator forgets his password, By resetting information related to security in the programmable controller 101, it can be used again as the programmable controller 101 having the security function.

  The programmable controller according to the present invention is useful for system development in which system developers are classified by hierarchy and assigned access authority. In addition, the programmable controller according to the present invention is useful for system development in which a recovery means when a password is forgotten must be installed.

1 is a diagram illustrating an overall configuration of a programmable controller according to a first embodiment. 6 is a diagram illustrating a configuration of user management information in Embodiment 1. FIG. 6 is a diagram showing a configuration of access control information in Embodiment 1. FIG. In Embodiment 1, it is a flowchart which shows operation | movement until a programmable controller authenticates the user who accessed via the tool and permits access to the file of access object. It is a flowchart which shows the process order which a programmable controller deletes the information regarding security, and all the internal data, when an administrator forgets his password. It is a figure which shows an example of the memory content of a system memory.

Explanation of symbols

1 User management information 2 Access control information 3 Login user information table 101 Programmable controller 102 MPU
103 Program memory 104 System memory 105 Data memory 106 Communication driver 107 Tool

Claims (6)

In a programmable controller in which only users who are permitted to access from the outside can access, and access control is performed on at least part of the files existing inside,
User management information used as information for authenticating a user, including an access level that is a user name, a password, and an access authority level, and whether or not the file can be accessed for each access level Access control information, which is information defined for the operation, includes a private memory stored,
For a user who tries to access a file to be accessed, the user name and password entered by the user at the time of access and the user name and password included in the user management information match, and the user is authenticated. If the access control information is stored in the private memory, the access control information is set within the range permitted in the access control information according to the user access level set in the user management information. A programmable controller characterized by allowing access to a file.   The programmable controller according to claim 1, wherein the access control information is set for each file in the programmable controller. A program memory in which a sequence program is stored;
A data memory storing environment setting data necessary for control processing;
Further comprising
The programmable controller according to claim 1, wherein the file to be accessed by the user is a file stored in the program memory or the data memory.   The programmable memory according to any one of claims 1 to 3, wherein the private memory further stores login user information that is information about a user who is logged in to the programmable controller. controller.   According to the authenticated initialization command, all data in the programmable controller including the user management information, the access control information, and login user information stored in the private memory can be erased. The programmable controller according to claim 4.   The programmable controller according to claim 5, wherein all data can be erased when there is no logged-in user.

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