Network management system providing logic signals over communication lines for detecting peripheral devices
US7603486B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 2002 |
| Grant date | Oct 13, 2009 |
| Priority date | — |
| Expiry date | Aug 13, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L43/0811
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting the presence and the type of network devices connected to a management device via transmission lines. The apparatus may include a pull-up resistor, a pull-down resistor, a filter, and a presence detector, the resistors superimposing a DC or low-frequency voltage on the transmission line. The impact, if any, of the DC voltage one communications equipment and circuitry can be reduced by a coupling that isolates the DC voltage. Similarly, the filter prevents transmitted data signals from interfering with the DC voltage level. The method and apparatus function regardless of whether the network device is functional or powered on, and different values of pull-up or pull-down resistors can be used to indicate the type of device that terminates the transmission line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.