Device for communicating real time data between a programmable logic controller and a program operating in a central controller

• US 5,038,318 A
• Filed: 12/17/1987
• Issued: 08/06/1991
• Est. Priority Date: 12/17/1987
• Status: Expired due to Term

• Current Assignee: Solaia Technology LLC
• Original Assignee: Square D Company (Schneider Electric SE)
• Inventors: Roseman, Brooks T.
• Primary Examiner(s): Heckler, Thomas M.
• Application Number:
  US07/134,353
• Time in Patent Office: 1,328 Days
• Field of Search: 364/200 MS File, 364/ 900 MS File, 364/308
• US Class Current: 712/30
• CPC Class Codes: G05B 19/052 Linking several PLC's
• CPC Class Codes: G06F 40/18 of spreadsheets form-filling G06F40/174

Abstract

Add-in program instructs operable through a general purpose spreadsheet program in a personal computer to move real-time status and control messages directly between cells in the displayed spreadsheet and addressed registers of programmable logic controllers (PLCs) is disclosed. The PLCs operate such as machine tools for processing stations and connect together and to an interface card in the personal computer over a network. The invention facilities a user'"'"'s real-time monitoring and control of the manufacturing performed at the machine tools or processing stations through mathematical and logical features of the spreadsheet, which are well known and easy for a user to implement.

Claims

1. A system for providing real time control of operating equipment with a programmable logic controller, said programmable logic controller being capable of receiving control messages to control operation of said equipment and being capable of transmitting status messages indicating a condition of said equipment, said system comprising:

A. a computer having an operably interconnected visual display, keyboard, memory and central processor, said computer for sequentially executing instructions contained in said memory in cooperation with characters received from said keyboard;

B. an interface electrically connected between said computer and said programmable logic controller for transmitting messages between said programmable logic controller and said computer;

C. spreadsheet instructions means contained in said memory for effecting a general purpose spreadsheet program in said computer, said spreadsheet instruction means providing cells displayable by said visual display, into which said user can insert information, @ functions that can be inserted into said cells via said keyboard and selectable menu commands to effect actions in said spreadsheet instruction means, said spreadsheet information means normally only being able to effect movement of information between files of data contained in said memory and said cells; and

D. add-in instruction means contained in said memory for presenting add-in @ functions and add-in menu commands operating through said spreadsheet instruction means, said add-in instruction means for moving messages directly between said cells and said programmable logic controller via said interface means, said messages moving from said cells to said programmable logic controller comprising said control messages for controlling the operation of said equipment and said messages moving from said programmable logic controller to said cells comprising said status messages indicating the condition of said equipment.

2. The system of claim 1 in which said add-in instruction means includes @read means for causing said programmable logic controller to transmit a status message to said spreadsheet instruction means.

3. The system of claim 2 in which said @read means includes characters indicating an @read function and route addresses of said interface means and said programmable logic controller.

4. The system of claim 3 in which said @read means includes characters indicating a certain register in said programmable logic controller, the contents of which are to be sent in said status message.

5. The system of claim 2 in which said cells of said spreadsheet instruction means are addressable by characters from said keyboard and said @read means are addressed into a certain cell by characters from said keyboard.

6. The system of claim 1 in which said add-in instruction means includes @write means for transmitting a control message to said programmable logic controller.

7. The system of claim 6 in which said @write means includes characters indicating an @write function and route addresses of said interface means and said programmable logic controller.

8. The system of claim 7 in which said @write means includes characters indicating a certain register in said programmable logic controller that is to receive said control message.

9. The system of claim 1 in which said add-in instruction means includes menu initialize means for moving initial system information to said interface means.

10. The system of claim 1 in which said add-in instruction means includes first file means for containing local variables used to move messages directly between said cells and said interface means and for containing said menu commands, said add-in instruction means also including second file means for containing said add-in @functions, and said spreadsheet instruction means including assignment means for assigning said first and second file means to specific memory locations.

11. A system for operating equipment by an operator, the system comprising:

A. a plurality of programmable logic controllers coupled to the equipment, said programmable logic controllers each transmitting messages on a network indicating the condition of said equipment;

B. a computer having operably interconnected visual display, keyboard, memory, and central processor, said computer for sequentially executing instructions contained in said memory;

C. interface means electrically connected between said computer and said network for receiving messages from each of said programmable logic controllers, said interface means including a plurality of message registers, of which at least one of said message registers is associated with each of said programmable logic controllers, the messages from each of said programmable logic controllers being overwritten on a preceding message in said registers, said interface means including interrupt means for interrupting operation of said computer in response to receiving a message in any one of said message registers;

D. spreadsheet instruction means contained in said memory for effecting a general purpose spreadsheet program in said computer, said spreadsheet instruction means providing cells into which said operator can insert information and menu commands selectable by said operator, said spreadsheet means normally only being able to effect movement of information between files of data contained in said memory and said cells; and

E. add-in instruction means contained in said memory for presenting add-in menu commands and interrupt selected instructions operating through said spreadsheet instruction means for said interrupt selected instructions to move sequentially received messages from said message registers to respective assigned address locations in said memory upon occurrence of each interrupt signal, and for said add-in menu commands to move said messages form said assigned address locations in said memory to respective assigned cells in said spreadsheet instruction means so that messages from said programmable logic controllers indicating the condition of said equipment can be saved and moved directly to said cells.

12. A device for transmitting and receiving electrical signals forming messages to and from respective addressable registers located in respective addressable programmable logic controllers that are connected together over a communications network, said device comprising:

A. process means connected to said communications network for moving said electrical signals forming messages to and from respective registers located in said processor means, said respective registers for each of said respective addressable programmable logic controllers being addressable form said communications network and accessible from said processor means;

B. spreadsheet means contained in said processor means, said spreadsheet means presenting a spreadsheet of cells into which information can be inserted to facilitate executing actions through said spreadsheet means, said spreadsheet means being capable of accessing said registers in said processor means through said actions;

C. add-in program means contained in said processor means for inserting in at least one cell information including the address of a particular register in a particular programmable logic controller to which a message is to be sent and indicating the content of said message; and

d. add-in program means contained in said processor means for executing an action in said spreadsheet means to cause said spreadsheet means to transmit said message from said cell through said registers in said process means to the said addressed particular register in said particular programmable logic controller.

13. The device of claim 12 in which said means for executing executes an @WRITE function.

14. A system for permitting real-time operation by a user of operating equipment with at least one programmable logic controller, said programmable logic controller including addressable registers, said programmable logic controller being capable of receiving messages addressed to said addressable registers to control operation of said equipment, and for transmitting messages from said addressable registers indicating the condition of said equipment, said messages being in the form of electrical signals, said system comprising:

A. process means having an operably interconnected visual display, keyboard, instruction storage memory and central processor for sequentially executing instructions contained in said instruction storage memory;

B. interface means coupled between said processor means and said programmable logic controller, said interface means including message registers capable of transmitting and receiving addressed messages to and from said addressable registers in said programmable logic controller and being accessible by said processor means, said interface means for transmitting addressed messages to said addressable registers in said programmable logic controller, and for presenting to said processor means information contained in received addressed messages form said addressable registers in said programmable logic controller, said interface means including interrupt means for interrupting the operation of said processor means in response to receiving an addressed message in any one of said message registers;

C. spreadsheet instruction means contained in said instruction storage memory for effecting a general purpose spreadsheet program in said processor means, said spreadsheet instruction means providing a spreadsheet having cells displayed by said visual display into which said user can insert information, @ functions that can be inserted into said cells by said user to effect actions in said spreadsheet program, and menu commands selectable by said user to effect actions in said spreadsheet program, said spreadsheet instruction means normally only being able to effect movement of information between files of data contained in said instruction storage memory and said cells; and

D. supplemental instruction means contained in said memory for operating through said spreadsheet instruction means to move messages directly between said cells and said addressable registers in said programmable logic controller through said interface means, so that said user can transmit addressed messages controlling the operation of said equipment directly from said cells to said addressable registers in said programmable logic controller, can request messages from said cells indicating the condition of said equipment, and can receive in said cells said messages initiated by said programmable logic controller indicating the condition of said equipment.