PROGRAMMABLE CONTROLLER AND PROGRAMMING TOOL FOR COMMUNICATION WITH LEGACY EQUIPMENT

• US 20130006397A1
• Filed: 07/01/2011
• Published: 01/03/2013
• Est. Priority Date: 07/01/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: FUKATSU, Noriyasu
• Granted Patent: US 8,832,670 B2
• Time in Patent Office: Days
• US Class Current: 700/86
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 2219/23334 Use of table with addresses for different modules, write new table if modified
• CPC Class Codes: G06F 8/41 Compilation
• CPC Class Codes: H04L 12/28 characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks] wireless communication networks H04W ; arrangements for dividing the transmission path H04W40/00

Abstract

A method of generating a symbol table for a programmable logic controller which executes high-level language program is provided. The method includes reading the high-level language program and an association table specifying relationship between devices controlled by the programmable logic controller and variable names in the high-level language program; compiling and linking the high-level language program and the association table for determining a physical address for each of the variable names and the corresponding devices; generating the symbol table by the compiling and linking, the symbol table defining the determined physical address for each of the devices; and storing the symbol table in the memory of the programmable logic controller. A programmable logic controller executing the high-level language program and storing the symbol table is also provided.

Claims

1. A method of generating a symbol table for a programmable logic controller which executes high-level language program, the method comprising:

reading the high-level language program and an association table specifying relationships between devices controlled by the programmable logic controller and variable names in the high-level language program;

compiling and linking the high-level language program and the association table for determining a physical address for each of the variable names and the corresponding devices;

generating the symbol table by the compiling and linking, the symbol table defining the determined physical address for each of the devices; and

storing the symbol table in a memory of the programmable logic controller.

2. A method of communication between a peripheral equipment and a programmable logic controller executing high-level language program, the method comprising:

receiving a request for reading or writing to a device controlled by the programmable logic controller, the request received from the peripheral equipment;

reading a symbol table to determine a physical address in a memory of the programmable logic controller for the device; and

reading from or writing to the determined physical address.

4. The method of claim 2, wherein:

the request includes a name of the device, and

the symbol table defines a relationship between the name of the device, a variable name corresponding to the device and used in the high-level language program, and a physical address in the memory of the programmable logic controller corresponding to the variable name.

3. A programmable logic controller that executes high-level language program for controlling devices, the programmable logic controller comprising:

a request receiving unit which receives a request for reading or writing to a device controlled by the programmable logic controller, the request received from a peripheral equipment;

a symbol table reading unit which reads a symbol table to determine a physical address in a memory of the programmable logic controller for the device; and

a physical address reading or writing unit which reads from or writes to the determined physical address.

5. The programmable logic controller of claim 3, wherein:

the request includes a name of the device, and

the symbol table defines a relationship between the name of the device, a variable name corresponding to the device and used in the high-level language program, and a physical address in the memory of the programmable logic controller corresponding to the variable name.