Patent Application
20100161085
The present invention generally relates to a peripheral device of a programmable controller, a method of variable substitution, and a computer program product thereof. The present invention particularly relates to a peripheral device of a programmable controller, a method of variable substitution, and a computer program product thereof that simplify creating and editing of a sequence program of a programmable logic controller (hereinafter, sometimes referred to as PLC).
Internal-memory addresses of a PLC have been defined in the codes of a sequence program that is created or edited in a peripheral device of the PLC.
However, recently, a sequence program is created by using variables instead of internal-memory addresses of a PLC. That is, instead of directly defining internal-memory addresses of the PLC, a sequence program is created by defining variables that substitute for the internal-memory addresses. A sequence program created by such a method includes a code in which, e.g., “LD (variable)” is defined instead of an internal-memory address “LD X0”.
Patent Document 1: Japanese Patent Application Laid-Open No. 2000-242313
Generally, to simplify creation of a new sequence program, an existing sequence program created in past is reused.
A sequence program needs to be compiled before using it in a PLC. When a new sequence program is created by reusing an existing sequence program, it is necessary to substitute old addresses in the existing sequence program by new addresses in the PLC while compiling.
When a project, which includes a sequence program with variables such as above substituted therein, is created by reusing an existing sequence program without variables, it is first necessary to copy the existing sequence program and then substitute variables for devices in the copied sequence program by declaring input-output addresses (input-output devices) as global variables and internal-memory addresses (internal devices) as local variables.
A global variable can be used in all programs in a specific project and is independent of any single program in the project. Thus, by declaring a global variable, it is possible to share its value in all programs in the project. On the other hand, a local variable can be used only in a program in which it is defined. That is, each local variable belongs to the program in which it is defined. Thus, a local variable is used when it is not necessary to share its value with other programs in the project. Thus, by using global variables and local variables, a program can be efficiently edited even by a plurality of people.
Conventionally, a programmer has to manually substitute variables for addresses while making sure that there is no duplication of addresses. That makes the substitution a complicated and time consuming task. Moreover, it is difficult to efficiently reuse an existing sequence program without variables.
A conventional technology is disclosed to automatically substitute global variables and local variables for memory addresses (refer to Patent document 1). However, such a conventional technology does not take into account reusing an existing sequence program without variables.
The present invention has been achieved to solve the above problems in the conventional technology and it is an object of the present invention to provide a peripheral device of a programmable controller, a method of variable substitution, and a computer program product thereof that enable to automatically and efficiently convert an existing sequence program without variables into a sequence program with variables substituted therein.
To solve the problems and achieve the object mentioned above, according to an aspect of the present invention, there is provided a peripheral device of a programmable controller for converting an existing program into a program with variables substituted therein. The peripheral device of a programmable controller includes a variable-information creating unit that extracts an address from the existing program, assigns a unique variable to the address, and creates variable correspondence information on correspondence between the address and the variable; and a substituting unit that substitutes the address with the variable based on the variable-correspondence information to convert the existing program into the program with variables substituted therein.
As just described, with the peripheral device of a programmable controller of the present invention, an address is extracted from an existing program, and a unique variable is assigned to the address. The address is associated with the variable to thereby automatically create variable-correspondence information on correspondence between the address and the variable. Based on the variable-correspondence information, the address is automatically substituted with the variable such that the existing program can be converted into a program with variables substituted therein. Thus, it is possible to automatically and efficiently convert an existing sequence program into a sequence programs with variables substituted therein.
Exemplary embodiments of a peripheral device of a programmable logic controller (PLC), a method of variable substitution, and a computer program product thereof according to the present invention are described in detail below with reference to the accompanying drawings. The present invention is not limited to the embodiments described below and can be modified in various manners without departing from its scope.
In a conventional program creating device, to create a new project of a sequence program with variables substituted therein by reusing an existing sequence program without variables, the existing sequence program is first copied to the new project. The input-output addresses (input-output devices) in the copied sequence program are then declared as global variables, while internal-memory addresses (internal devices) are declared as local variables such that the devices in the copied sequence program are substituted by variables.
With a conventional technology, a programmer has to manually substitute variables for addresses while making sure that there is no duplication. That makes the programmer overburdened with the substitution task. Moreover, it is difficult to efficiently reuse an existing sequence program without variables.
Unlike the conventional technology, it is possible to automatically perform the substitution task by using the program creating device 1 of the embodiment. Thus, without troubling the programmer for manual substitution of variables, a new project of a sequence program can be efficiently created by reusing an existing sequence program without variables. As shown in
The input device 3 is used for inputting operational instructions regarding the program creating device 1. The display device 5 displays information such as the sequence program or processing data in the program creating device 1.
The external storage device 7 stores therein existing project data 71 created in past. The existing project data 71 stored in the external storage device 7 includes an existing sequence program 72 without variables and a device comment 73 adjunctive to the existing sequence program 72. The device comment 73 includes an explanatory comment regarding each address (device) defined in the existing sequence program 72.
To create a new project of a sequence program with variables substituted therein by reusing an existing sequence program without variables, the variable-table creating unit 111 in the program creating unit 11 copies the existing sequence program 72 and the device comment 73 from the external storage device 7 and stores them in the storage unit 13.
The variable-table creating unit 111 then classifies addresses present in the codes of the copied existing sequence program 72 by searching an address classification table (address classification information), as shown in
The variable-table creating unit 111 then creates a variable table (variable information), as shown in
The global-variable-table creating unit 112 extracts the variables having the classification as global and the corresponding addresses from the variable table shown in
As shown in
The local-variable-table creating unit 113 extracts the variables having the classification as local and the corresponding addresses from the variable table shown in
The substituting unit 114 substitutes a variable for each address present in the code of the existing sequence program 72 based on the variable table, which is shown in
When substituting a variable for each address present in the code of the existing sequence program 72, the substituting unit 114 uses a comment, which is included in the device comment 73 shown in
The program creator 115 uses the sequence program with variables substituted therein to create a new sequence program.
The storage unit 13 stores therein various types of programs necessary for processing in the program creating device 1, or sequence programs and data generated during the processing.
The new project memory 133 stores therein a new project data 139 in which, e.g., a global-variable table 134, a sequence program A 135A that is newly created or edited by reusing the existing sequence program 72, a local-variable table A 136A corresponding to the sequence program A 135A, a sequence program B 135B that is newly created or edited by reusing the existing sequence program 72, a local-variable table B 136B corresponding to the sequence program B 135B, an address classification table 137, and a variable table 138 are stored. The storage unit 13 copies the existing sequence program 72 and the device comment 73 from the external storage device 7, and stores them in the data memory 132.
The communication unit 15 functions as an information input-output unit to communicate information between the program creating device 1 and the external storage device 7, which is externally connected to the program creating device 1. The controlling unit 17 controls the program creating device 1 in entirety.
Given below is the description of a process of creating a new sequence program by reusing an existing sequence program created in past by implementing the program creating system of the embodiment. First, a process of creating a variable table is described with reference to
To create a variable table, the variable-table creating unit 111 first copies the existing sequence program 72 and the device comment 73 from the external storage device 7, and stores them in the data memory 132 of the storage unit 13 (step S101). The variable-table creating unit 111 then starts searching for addresses (devices) from the beginning of the codes of the existing sequence program 72 and extracts the addresses (devices) (step S102).
The variable-table creating unit 111 refers to a variable table to determine if the extracted addresses (devices) have already been registered in the variable table (step S103). If the extracted addresses (devices) are yet to be registered in the variable table (NO at step S103), the variable-table creating unit 111 registers the extracted addresses (devices) in the variable table (step S104). The variable-table creating unit 111 classifies the addresses (devices) (global or local) by searching the address classification table 137 stored in advance in the storage unit 13 for the addresses, and registers the classification of the addresses (global or local) in the variable table (step S105).
The variable-table creating unit 111 then searches the copied device comment 73 to determine whether there is a comment regarding each address (step S106). If there is a comment regarding an address (YES at step S106), the variable-table creating unit 111 registers the comment as the variable of the corresponding address in the variable table (step S107). On the other hand, if there is no comment regarding an address (NO at step S106), the variable-table creating unit 111 registers fixed characters assigned in advanced or assigned on a case-by-case basis as the variable of the corresponding address in the variable table (step S108).
After registering the variables, the variable-table creating unit 111 determines whether all the addresses (devices) in the codes of the existing sequence program 72 are extracted and registered in the variable table (step S109). If all the addresses (devices) in the codes of the existing sequence program 72 are not yet registered in the variable table (NO at step S109), the process returns to step 5102 for extraction of remaining addresses in the codes of the existing sequence program 72. If all the addresses (devices) in the codes of the existing sequence program 72 are registered in the variable table (YES at step S109), the process of creating the variable table is complete.
Meanwhile, at step 5103, if the extracted addresses (devices) are determined to be registered in the variable table (NO at step S103), the process jumps to step S109. The variable-table creating unit 111 then determines whether all the addresses (devices) in the codes of the existing sequence program 72 are extracted and registered in the variable table (step S109).
If all the addresses (devices) in the codes of the existing sequence program 72 are not yet registered in the variable table (NO at step S109), the process returns to step S102 for extraction of remaining addresses in the codes of the existing sequence program 72. If all the addresses (devices) in the codes of the existing sequence program 72 are registered in the variable table (YES at step S109), the process of creating the variable table is complete.
By performing the abovementioned process, the variable table 138 can be created in the program creating device 1 of the embodiment based on the existing sequence program 72 and the device comment 73 in the existing project data 71, as shown in
Given below is the description with reference to
To perform variable substitution in the program creating device 1, the substituting unit 114 in the program creating unit 11 starts searching for addresses (devices) from the beginning of the codes of the existing sequence program 72, which is copied in the storage unit 13, and extracts the addresses (devices) (step S201). The substituting unit 114 then searches for variables corresponding to the extracted addresses and extracts those variables (step S202).
The substituting unit 114 substitutes the addresses in the existing sequence program 72 by the corresponding variables and stores the sequence program after substitution in the new project memory 133 as the sequence program A 135A (step S203). After the substitution is complete, the substituting unit 114 determines whether all the addresses (devices) in the existing sequence program 72 are substituted by the corresponding variables (step S204).
If all the addresses (devices) in the existing sequence program 72 are not yet substituted by the corresponding variables (NO at step S204), the process returns to step S201. On the other hand, if all the addresses (devices) in the existing sequence program 72 are substituted by the corresponding variables (YES at step S204), the process of variable substitution is complete.
With this, according to the embodiment, based on the existing sequence program 72 in the existing project data 71 and the variable table 138, the addresses (devices) in the existing sequence program 72 can be automatically substituted by variables in the program creating device 1 as shown in
Given below is the description with reference to
To declare global variables in the program creating device 1, the global-variable-table creating unit 112 in the program creating unit 11 extracts from the variable table 138 variables having the classification as global and the corresponding addresses (devices) (step S301). The global-variable-table creating unit 112 then registers the extracted global variables and the corresponding addresses (devices) in the global-variable table 134 (step S302).
After registering the extracted global variables and the corresponding addresses (devices), the global-variable-table creating unit 112 determines whether all the global variables and the corresponding addresses (devices) in the variable table 138 are registered in the global-variable table 134 (step S303).
If all the global variables and the corresponding addresses (devices) in the variable table 138 are not yet registered in the global-variable table 134 (NO at step S303), the process returns to step S301. On the other hand, if all the global variables and the corresponding addresses (devices) in the variable table 138 are registered in the global-variable table 134 (YES at step S303), the process of declaring the global variables is complete.
By the abovementioned process, based on the variable table 138, the global-variable table 134 can be automatically created for declaring the global variables, as shown in
Given below is the description with reference to
To declare local variables in the program creating device 1, the local-variable-table creating unit 113 in the program creating unit 11 extracts from the variable table 138 variables having the classification as local and the corresponding addresses (devices) (step S401). The local-variable-table creating unit 113 then registers the extracted local variables and the corresponding addresses (devices) in the local-variable table A 136A (step S402).
After registering the extracted local variables and the corresponding addresses (devices), the local-variable-table creating unit 113 determines whether all the local variables and the corresponding addresses (devices) in the variable table 138 are registered in the local-variable table A 136A (step S403).
If all the local variables and the corresponding addresses (devices) in the variable table 138 are not yet registered in the local-variable table A 136A (NO at step S403), the process returns to step S401. On the other hand, if all the local variables and the corresponding addresses (devices) in the variable table 138 are registered in the local-variable table A 136A (YES at step S403), the process of declaring the local variables is complete.
By the abovementioned process, based on the variable table 138, the local-variable table A 136A corresponding to the sequence program A 135A can be automatically created for declaring the local variables, as shown in
The program creator 115 in the program creating device 1 can reuse the sequence program A 135A with variables substituted therein to newly create, e.g., the sequence program B 135B and store it in the new project memory 133. At that time, it is possible to declare a new global variable by adding it and a corresponding address (device) in the global-variable table 134, as described above. Moreover, as described above, it is also possible to create the local-variable table B 136B corresponding to the sequence program B 135B for declaring local variables.
Thus, the sequence program A 135A with variables substituted therein can be reused to newly create the sequence program B 135B, as shown in
To sum up, as shown in
Moreover, the sequence program B 135B, the local-variable table B 136B, and the global-variable table 134 in the new project data 139 can be created and modified based on the sequence program A 135A, the local-variable table A 136A, the global-variable table 134, and the variable table 138 in the new project data 139.
As described above, the program creating device 1 is a peripheral device of a PLC for creating and editing a sequence program of the PLC. By using the program creating device 1, it is possible to create a sequence program in which addresses (devices) such as input-out addresses (input-output devices) or internal memory addresses (internal devices) of the PLC are substituted by variables. That is, a sequence program is created by substituting variables for addresses, instead of directly defining the addresses.
Moreover, it is possible to reuse an existing sequence program created in past to create a new sequence program in the program creating device 1. A new sequence program with variables substituted therein can be created by reusing an existing sequence program also with variables substituted therein. Furthermore, a new sequence program with variables substituted therein can also be created by reusing an existing sequence program without variables.
In that case, addresses (devices) in the existing sequence program without variables are automatically substituted by variables in the program creating device 1 to create the new sequence program with variables substituted therein.
Although an input device and a display device are arranged external to a program creating device as described above, it is also possible to configure a program creating device to include the input device and the display device. Moreover, although an external storage device is directly connected to the program creating device as described above, it is also possible to make the connection between the program creating device and the external storage device through a network. Moreover, although the existing project data 71 is stored in the external storage device 7 as described above, it is also possible to store the existing project data 71 in the storage unit 13 included in the program creating device 1.
The abovementioned processes of variable substitution and program creation can be programmed and executed on a computer (a peripheral device of a programmable controller) that includes a CPU, and a storage device as shown in
The input device 201 includes a keyboard, a mouse, a touch panel, a scanner, etc., and is used for inputting information. The display device 202 displays output information or the information input from the input device 201. The CPU 203 executes various programs. The memory 204 stores therein temporary information generated when programs are built and executed in the CPU 203. The storage device 205 stores therein programs and the temporary information generated when the programs are executed. The storage-medium drive 206 loads therein a storage medium, reads programs or data from the storage medium, and stores that information in the memory 204 or the storage device 205. The network interface 207 connects the computer to a network. The bus 208 interconnects all the abovementioned units of the computer.
Although the above description is regarding an exemplary case of sequence program creation of a PLC, the present invention is not limited to sequence program creation of only a PLC but can be implemented in a general case of sequence program creation.
A peripheral device of a programmable controller according to the present invention is suitable for creating a new sequence program by reusing an existing sequence program without variables.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/052982 | 2/19/2007 | WO | 00 | 4/10/2008 |
