LINE DELAY COMPENSATION FOR DIGITAL TRANSMISSION SYSTEMS UTILIZING LOW POWER LINE DRIVERS

摘要

84-3-124 CN -20- LINE DELAY COMPENSATION FOR DIGITAL TRANSMISSION SYSTEMS UTILIZING LOW POWER LINE DRIVERS : In a data transmission system including a central subsystem coupled by transmission lines of different lengths to a plurality of remote subsystems, methods and apparatus for synchronizing responses to messages transmitted by the central subsystem to compensate for different line delays are provided. The messages are transmitted by the central subsystem during the first portion of a frame, while the responses are transmitted by the remote subsystems during a second portion of the frame. In each of the remote subsystems, a compensation delay equal to a maximum line delay associated with the longest of the transmission lines less an actual line delay associated with the transmission line connected to that remote subsystem is determined. The response to the message is then delayed by the compensation delay so that the responses from each remote subsystem arrive at the central subsystem delayed by the maximum time delay. The central subsystem detects the response during a detection internal delayed by the maximum time delay after the end of the message.