Use of a single central transmit and receive mechanism for automatic

Abstract

A concentrator having a single medium access controller for monitoring a plurality of communication lines is provided. Each of the communication lines corresponds to a network and carries identification signals periodically transmitted by devices on the corresponding network. The medium access controller includes a transmit unit and a receive unit. The transmit unit sequentially broadcasts concentrator identification signals over each of the communication lines. The transmit unit sequences through the communication lines at a rate to insure that a concentrator identification signal is sent over each communication line during a predetermined transmit interval. The receive unit sequentially monitors the signals on each of the communication lines. The receive unit monitors the signals on any given communication line for a predetermined monitoring period before sequencing to the next communication line. The duration of the monitoring period for a given communication line is at least as long as the longest identification signal transmit interval for any device on the communication line. Consequently, the receive unit will detect an identification signal from all of the active devices on a given communication line during the monitoring period for the communication line. The receive unit stores an indication of the identification signals it detects and the ports on which they were detected. This stored information may be used by a network management station to generate a map showing how the concentrator is connected to other devices.