1.2 TI Precision Labs - RS-485: How far and fast can RS-485 communicate?
Questions about RS-485 in terms of distance and speed are commonly asked. This video provides color to this topic and includes an example of how a fast data rate on a long distance transmission line can be affected by the cable's parasitic capacitance, parasitic resistance, and system's jitter. Advice for evaluating insertion loss or cable loss is included as well. Ultimately, strong drive strength RS-485 drivers are desirable but the quality of the communication medium (cabling) is the limiting factor for far distance transmission.