Abstract: A device for permanent installation in series with a time division multiplex digital data transmission line for accessing data signals carried by the line without interruption or degradation of the signals. This novel device is a regenerative line access module (RLAM) that receives incoming data signals that may be attenuated and distorted, and regenerates or reshapes the pulses thereof. The regenerated signals are passed to the output of the RLAM, amplified, and retransmitted on the transmission line, and are also used for generating a clock signal having a fundamental signal equal in frequency to the fundamental frequency of the incoming data signals but delayed slightly therefrom. When it is desired to access a selected subscriber channel, the RLAM blocks the throughput of the incoming bit stream during the period of the selected subscriber data byte. The data byte thus deleted may be dropped for local use if desired.

Abstract: A device for permanent installation in series with a time division multiplex digital data transmission line for accessing data signals carried by the line without interruption or degradation of the signals. The device, referred to as a line access module (LAM), operates in a throughput mode in which incoming signals pass through the device without modification and a bypass mode in which the incoming signals are bypassed to an external common electronics circuit and reinserted in the outgoing transmission line.