Synchronous & Asynchronous Data Transfer

There are two types of systems for data transfer, asynchronous and synchronous. The main difference between the two transfer systems lies in the timing of the transfer scheduled by the entry point.

Synchronous

• Synchronous systems synchronize their clocks before a transmission begins. Both ends of the synchronous system conduct a negotiation cycle where an exchange of parameters and information is made. Once the connection is established, the transmitter sends the signal and the receiver receives it and sends back a message about what was transmitted.

Asynchronous

• An asynchronous system is made up of a transmitter, a wire and receiver, but there is no coordination about the timing of individual data bits. The transmitter and receiver use clocks to measure the length of a bit. The transmitter sends out the signal and the receiver receives the incoming signal and retimes its clock to match.

Advantages and Disadvantages

• Asynchronous data transmission is generally faster but less reliable. Synchronous data transmission takes longer if it is on low error-rate lines, but is quicker if it is a system where the transmission medium is by radio signal, laser beam or electric wire; however, these mediums are less reliable.