Asynchronous Transmission is often referred to as start-stop transmission because of its nature, that is the sender can send a character at any time conveniet and the receiver will accept it. Asynchronous communication lines remain in an idle state until the hardware on the line is ready to transmit. Since the line is idle a series of bits have to be sent to the receiving node to notify it that there is more data coming. When data is finished, the node has to be notified that the transmission is complete and to go back to an idle state. Hence the STOP bits are to be sent. This pattern continues for the duration of the time the link is operative. This is the characterstic of many terminals when on a terminal, the time spent between successive keystrokes would vary. Thus, in asynchronous transmission, data is transmitted character by character at irregular intervals.
No comments:
Post a Comment