A time domain reflectometer transmission line interface includes a pulse driver for generating a transmitted pulse signal. A coupling transformer coupled to the pulse driver couples the transmitted pulse signal to a transmission line and receives a reflected pulse signal from the transmission line. A differential amplifier is coupled to the pulse driver and to the coupling transformer through a network configured such that said transmitted pulse is balanced at the inverting and non-inverting inputs of the differential amplifier.
CROSS-REFERENCE TO RELATED APPLICATIONS
The present Application is related to U.S. application Ser. No. 09/967,633, filed Sep. 26, 2001, titled MULTI-FUNCTION DATA ACQUISITION SYSTEM AND METHOD, and U.S. application Ser. No. 09/967,686, filed Sep. 26, 2001, titled TIME DOMAIN REFLECTOMETER WITH DIGITALLY GENERATED VARIABLE WIDTH PULSE OUTPUT, the disclosures of which are incorporated herein by reference.
A method and system for performing integrated adjustable short-haul/long-haul time domain reflectometry (TDR). A TDR pulse count is set to a predetermined number. Next, a TDR pulse is transmitted through a cable. The width of the TDR pulse is a function of the multiplication of the TDR pulse count with the period of a TDR clock. It is then determined whether the TDR pulse has been reflected back. If the TDR pulse has not been reflected, the TDR pulse count is successively increased to successively increase the width of the transmitted TDR pulse until a reflection is detected--indicating an open in the cable. Furthermore, it eliminates false detections of cable opens. Moreover, the system can be combined into a line interface unit (LIU) integrated circuit such that TDR functionality can be performed automatically without the use of a technician.
A novel method and system for fault identification is provided. A test head that is operable to generate a test signal along a pathway is employed. The test head is based on time domain reflectometry, and is thus operable to provide an estimated physical distance of where a fault occurs along the pathway. The response test signal is matched with a known set of information about the cable and junctions and other components associated with the pathway, including information about the physical location of those components. As part of the matching, an actual real-world physical location can be identified as to where the fault likely occurs, thereby reducing the need for a service technician to attempt to physically locate the fault himself.
