Flow control

Flow control (or handshaking) is a method used by various devices to cope when one device is sending data to the other faster than it is being processed. The receiving device can ask the sending device to pause while it catches up. For example, if a printer's buffer is full of data that it still has to print, it tells the computer to stop sending data until it is ready to accept more.

There are two methods of flow control which can be configured using the Serial Manager:

• hardware flow control (such as RTS/CTS) consists of two control signal lines between the DTE and DCE that are used to control the flow of data between the devices.

• software flow control (such as XON/XOFF) uses special control characters embedded in the data stream. This method will not work with binary data as the control characters themselves could be data.

Flow control is usually necessary because there can be different data transfer speeds between two computers connected with modems.