Power line carrier communication system for monitoring refrigerated containers
US4885564A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 1988 |
| Grant date | Dec 5, 1989 |
| Priority date | — |
| Expiry date | May 3, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/40
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A power line carrier communication system for monitoring refrigerated containers which includes a master monitoring unit and a first power line interface which interchange messages in a first format. The first power line interface translates the first format to a second format suitable for power line environment, and messages in the second format are applied to a power line. Remote monitoring units receive the messages from the power line, and they return messages to the power line containing status data relative to refrigerated containers. The second format includes a message starting preamble having a duration and logic level which is not duplicated by normal operation of the apparatus, enhancing the probability of proper message synchronization and reception over noisy power line environments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.