The serial interface is a two-way communications device meaning that it can send and receive data at the same time. The speed in which the interface communicates is denoted by the “baud rate”.
The RS-232 standard imposes a cable length limit of 50 feet; however, this is usually ignored since a cable can be as long as 10000 feet at baud rates up to 192000 if you use a high quality, well shielded cable. The external environment has a large effect on lengths for unshielded cables. In electrically noisy environments, even very short cables can pick up stray signals.
