Patent · US Expired

Fault processor for programmable controller with remote I/O interface racks

US3997879A · kind A · utility

36Cited by
2References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 24, 1975
Grant dateDec 14, 1976
Priority date
Expiry dateDec 24, 1995

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05B2219/25458
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A programmable controller includes four remotely located input/output interface racks which are connected by cables to an I/O scanner circuit which is centrally located with the controller processor and memory. Input and output data is serially transmitted between the I/O scanner circuit and the interface racks, and fault processors are located in both the I/O scanner circuit and the interface racks to monitor the operation. The fault processors include fault tolerant detector circuits which ignore erroneous transmissions caused by industrial noise, but which initiate a shutdown process when malfunctions occur. The shutdown process is controlled by a programmable disabling circuit which is responsive to program instructions stored in the controller memory to allow independent, quasi-independent, or dependent operation of the machines connected to each of the four interface racks.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.