10.2.1.1 Data Rate and Bus Length
There is an inverse relationship between data rate and bus length, meaning the higher the data rate, the shorter
the cable length; and conversely, the lower the data rate, the longer the cable may be without introducing data
errors. While most RS-485 systems use data rates between 10 kbps and 100 kbps, some applications require
data rates up to 250 kbps at distances of 4000 feet and longer. Longer distances are possible by allowing for
small signal jitter of up to 5 or 10%.