Applied research study on noise effects on logical level data transmission

Effects influencing the success of data transmission of logic level in a noisy environment were investigated. There are limits of transmission that on one hand arise as a result of circuit internal constraints and on the other hand as a result of interference noise. To the first belong effects such as signal attenuation caused by the transmission line and line reflections, to the second disturbances due to ground noise, crosstalk, and radiated interference. Quantitative results on the influence of these different effects on data transmission are presented. Special attention was paid to susceptibility to ground noise. Several types of data transmission circuits, single-ended ones and balanced ones, with and without an isolation device, were analyzed. Seven classes of data transmission circuits were established. For each of these the limits of transmission expressed in terms of maximum line length, maximum data rate, and permissible interference noise were determined.