Synchronous vs asynchronous communication systems

[safwatonline]

Sync. vs async.

hello,
i need to now the advantage of syncronous communication systems over async. ones??

 

[mshareef]

Re: Sync. vs async.

Hello:

Asynchronous Communication (independent transmit & receive clocks)

*Simple interface (limited data rate, typically < 64 kbps)
*Used for connecting: Printer, Terminal, Modem, home connections to the Internet
*No clock sent (Tx & Rx have own clocks)
*Requires start and stop bits which provides byte timing and increases overhead
*Parity often used to validate correct reception

Synchronous Communication (synchronised transmit & receive clocks)

*More complex interface (high data rates supported up to ~ 10 Gbps)
*Used for: Connections between computer and telephony networks
*Clock sent with data (more configuration options)

Synchronous transmission has the advantage that the timing information is accurately aligned to the received data, allowing operation at much higher data rates. It also has the advantage that the receiver tracks any clock drift which may arise (for instance due to temperature variation). The penalty is however a more complex interface design, and potentially a more difficult interface to configure (since there are many more interface options).

 

[Miguel Gaspar]

Sync. vs async.

mshareef answear is a good one.
However asynchronous communicatios are for short distances low velocities, they easily lost data and is from characterto characters communiations, error detections are for each character.

Synchronous are for long distances and high speeds, they transmitt long strings of characters and have algorythms to detect errors.