Negative-acknowledge character
"Nak" and "NAK" redirect here. For other uses, see Nak (disambiguation).
- In telecommunications, a negative-acknowledge character (NAK or NACK) is a transmission control character sent by a station as a negative response to the station with which the connection has been set up.
- In Binary Synchronous Communications protocol, the NAK is used to indicate that a transmission error was detected in the previously received block and that the receiver is ready to accept retransmission of that block.
- In multipoint systems, the NAK is used as the not-ready reply to a poll.
In the ASCII code, the NAK character is 21 (decimal), or ^U (CTRL-U). EBCDIC uses 0x3D. Unicode also defines a visible representation at U+2415(␕).
See also
References
This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C" (in support of MIL-STD-188).
This article is issued from Wikipedia - version of the Sunday, November 15, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.