×

Method and apparatus for symbolic ladder logic programming with automatic attachment of addresses

  • US 5,349,518 A
  • Filed: 06/30/1989
  • Issued: 09/20/1994
  • Est. Priority Date: 06/30/1989
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of providing symbol help in a program editor executed by a computer, the program editor being used by an operator for the displaying and editing of a ladder logic program on a monitor attached to the computer, wherein the ladder logic program is comprised of instructions operating on elements of data tables, the method comprising:

  • (a) maintaining a symbol assignment record in the computer, wherein the symbol assignment record identifies a correspondence between symbols and elements of the data tables, wherein each element is assigned to a specific symbol and each symbol represents a specific element, so that instructions in the ladder logic program reference an element using a symbol representing the element;

    (b) displaying a list of symbols obtained from the symbol assignment record on the monitor while the program is being edited, receiving a command from the operator selecting a symbol from the displayed list of symbols, and modifying an operator-identified instruction in the program so that it references the selected symbol; and

    (c) wherein the displaying step (b) further comprises receiving commands from the operator specifying a portion of a desired symbol, and displaying in the list of symbols only those symbols from the symbol assignment record which match the portion of the desired symbol.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×