Logic-level serial

Logic Level Serial is the use of the serial communication protocol at a 0 to 5 volt logic level. The logic level is the transmission protocol. This allows RS-232 style communications to be sent at a much lower and less complex voltage level. Where 0 is 0 volts and 1 is 5 volts, but can also fluctuate between 0 and 3.3 volts as well. It is also called TTL Serial