National Instruments NI-488.2 - Manual (Page 128)

Glossary
NI-488.2 User Manual G-8 ni.com
status byte The IEEE 488.2-defined data byte sent by a device when it is serially
polled.
status word See Ibsta .
synchronous Refers to the relationship between the GPIB driver functions and a process
when executing driver functions is predictable; the process is blocked until
the driver completes the function.
System Controller The single designated Controller that can assert control (become CIC of the
GPIB) by sending the Interface Clear (IFC) message. Other devices can
become CIC only by having control passed to them.
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.