No. The RS-485 data transceivers used in the MD485 feature fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open or shorted. Because of this, biasing resistors are not needed. The transceivers also feature reduced slew-rate drivers that minimize electromagnetic interference (EMI) and reduce reflections. Because of this, termination resistors do not need to be used for most applications.