User`s guide

Agilent VISA User’s Guide 151
IO Libraries
Application programming interfaces (APIs) for direct I/O
communication between applications and devices. There
are four Agilent IO Libraries in the Agilent IO Libraries
Suite: VISA, VISA COM, SICL, and Agilent 488.
Listener
A device that can receive data from the bus when
instructed (addressed to listen) by the System Controller.
lock
A state that prohibits other users from accessing a
resource such as a device or interface.
logical unit
A number associated with an interface. A logical unit, in
SICL and Agilent VEE, uniquely identifies an interface.
Each interface on the controller must have a unique
logical unit.
mapping
An operation that returns a reference to a specified
section of an address space and makes the specified range
of addresses accessible to the requester. This function is
independent of memory allocation.
non-Controller role
A computer is in a non- Controller role when it acts as a
device communicating with a computer that is in a
Controller role.
notification area
The area on the Windows taskbar where notifications are
posted, typically in the lower right corner of the screen.
Also called taskbar notification area or Windows
notification area.