System for communicating with electronic equipment

摘要

In accordance with the teachings of the present invention, a communication system ( 17 ) is provided for generating and monitoring data over pre-existing conductors ( 2 A- 2 D) between associated pieces of networked computer equipment ( 3 A- 3 D). The system includes a communication device ( 16 ) attached to the electronic equipment that transmits information to a central module ( 15 ) by impressing a low frequency signal on the pre-existing data lines of the remotely located equipment. A receiver ( 6 ) in the central module ( 15 ) monitors the low frequency data on the data lines to determine the transmitted information of the electronic equipment. The communication device may also be powered by a low current power signal from the central module ( 15 ). The power signal to the communication device may also be fluctuated to provide useful information, such as status information, to the communication device. Relocation of the electronic equipment with attached communication device to another location on the network is detected immediately and may be used to update a database. This invention is particularly adapted to be used with an existing Ethernet communications link or equivalents thereof.