Method and apparatus for program navigation and editing for ladder logic programs by determining which instructions reference a selected data element address
US5267145A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1992 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Feb 14, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S715/967
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The present invention is a method that provides productivity aids for developing, debugging, and troubleshooting ladder logic programs used in Programmable Logic Controllers (PLCs). The present invention discloses methods for searching ladder logic programs of programmable logic controllers for instructions, addresses, and symbols. The user can select an address or symbol in the ladder logic program and display on a computer a cross-reference list for the selected address or symbol. The cross-reference list shows all ladder logic instructions, and their locations in the ladder logic program, that use the selected address or symbol. An instruction location can be selected from the cross-reference list and the corresponding point in the ladder logic program will be displayed on the computer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.