National Instruments NI-488.2 - Manual (Page 125)

Glossary
NI-488.2 User Manual G-8 ni.com
T
TAD Talk Address. See also MTA .
Talker A GPIB device that sends data messages to Listeners.
TCT Take Control—The GPIB command used to pass control of the bus from
the current Controller to an addressed Talker.
timeout A feature of the GPIB driver that prevents I/O functions from hanging
indefinitely when there is a problem on the GPIB.
TLC An integrated circuit that implements most of the GPIB Talker, Listener,
and Controller functions in hardware.
U
ud Unit descriptor—A variable name and first argument of each function call
that contains the unit descriptor of the GPIB interface or other GPIB device
that is the object of the function.
UNL Unlisten—The GPIB command used to unaddress any active Listeners.
UNT Untalk—The GPIB command used to unaddress an active Talker.