Fault detection apparatus for a programmable controller
US4251883A · kind A · utility
22Cited by
5References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1979 |
| Grant date | Feb 17, 1981 |
| Priority date | — |
| Expiry date | Apr 16, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/14053
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A battery monitoring circuit in a programmable controller generates a logic signal when it senses a low output voltage from a memory back-up battery. A controller processor is programmed to set a fault status bit and store it in a memory with input/output status data. The fault status bit is output to an I/O interface rack together with input/output status data during an I/O scan routine. The fault status bit generates a logic signal to a fault indicating device on the I/O interface rack to signal an under-energized memory battery in the controller processor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.