An RS-485 bus consists of multiple transceivers connecting in parallel to a bus cable. To eliminate line reflections, each cable end is terminated with a termination resistor, R_T, whose value matches the characteristic impedance, Z₀, of the cable. This method, known as parallel termination, allows for higher data rates over longer cable length.

Figure 9-1 Typical RS-485 Network With Half-Duplex Transceivers