4.5.6.6 End of Text/Acknowledge (etx/ack)
The end of text/acknowledge (etx/ack) feature is used with another type of handshaking protocol on some systems to prevent data overflow. The etx/ack feature also uses software to regulate the flow of data to the input buffer by exchanging signals with the host computer. It is recommended that this feature be enabled by systems that support etx/ack to prevent the loss of data.
NOTE: The etx/ack feature is not supported on Digital systems. Use xon/xoff if you have a Digital system.
