Glossary
ENQ
Control character used to enquire as to the identification or status of a remote device.
Even Parity
Even parity refers to the addition of a 0 value or 1 value bit to the data bits which form a character to cause an even number of 1 value data bits to be sent. See also Parity.
ETX
Control character which indicates the End of Text in a transmitted message.
F
Firmware
Computer program stored permanently in Read Only Memory.
Forward Error Correction (FEC)
Technique of transmitting additional information with the original data so that if small errors are detected the correct information can be recreated by the receiving end without requiring a re- transmission.
Frame
See Block.
Frequency Modulation (FM)
A method of transmitting information by varying the carrier frequency.
Frequency Shift Keying
A form of frequency modulation in which the frequency of the carrier is shifted between two frequencies to represent digital data.
Front-end Processor
Computer equipment designed primarily for communications control associated with a large mainframe.
Full Duplex
Data transmission which allows data to flow in two directions at the same time.
G
Gateway
An electronic connection of some type, generally transparent to the user, by which multiple computers can be connected together.
Page 271
