Method and apparatus for introducing program changes in program-controlled systems
US4425618A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1981 |
| Grant date | Jan 10, 1984 |
| Priority date | — |
| Expiry date | Nov 23, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/23329
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An arrangement for introducing modifications in the program of a program-controlled system. Each time a modified version of a selected program function is stored in the system, it is tagged with a function sequence number; meanwhile, the original version of the program function is retained in the system. Each time a program process is initiated, it is tagged with a process sequence number. The two types of sequence numbers are assigned from a common source. Whenever the selected program function is called by a program process, a comparison is made between the process sequence number and the function sequence number. If the comparison indicates that the process was initiated before the modification was stored in the system, the original version of the selected program function is executed; otherwise, the modified version is executed. Thus, the original version or the modified version is used consistently throughout the active life of a process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.