A type of interface converter used to extend the distance of a digital connection by converting the digital signal to a low-voltage, low-impedance signal that can transmit more effectively and over longer distances on dedicated, specially conditioned twisted-pair circuits.The RS-232 specification (more correctly known as EIA-232), for example, generally limits the distance between devices to 50 feet at transmission rates of 56 kbps. At lower speeds, line drivers can reshape the digital pulses to extend that distance considerably.At speeds of up to 9.6 kbps, for example, line drivers can extend that limitation to 500