Extended Diagnostic Feature in a Transmission System
Original Publication Date: 1985-Aug-01
Included in the Prior Art Database: 2005-Feb-19
In a data communication network comprising a local station 1 and a remote tributary station 2, tributary equipment failures have to be reported to the local station. The use of a test and alarm circuit, associated with each (local or remote) modem, has already been recommended. Such a circuit, mainly intended for reporting power failures, is used to detect a failure and generate a tone which is transmitted to the local station over the transmission channel. An extension of such a function is proposed here which, in addition, is based on microcode implementation, rather than pure hardware. For that purpose, at the tributary station, any detected error condition within the modem will cause a "reset" condition on the modem and will start a 10-second timer.