National Instruments GPIB-PC - page 107

BASICA/QuickBASIC GPIB-PC Function Calls Section Four A
GPIB-PC User Manual 4A-32 ©National Instruments Corp.
BASICA/QuickBASIC BASICA/QuickBASIC
IBFIND IBFIND
Purpose: Open device and return the unit descriptor associated with
the given name
Format: CALL IBFIND (BDNAME$,BD%)
Remarks: BDNAME$ is a string containing a default or configured
device or board name. BD% is a variable containing the
unit descriptor returned by IBFIND.
IBFIND returns a number that is used in each function to
identify the particular device or board that is used or is the
object of that function. Calling IBFIND is required to
associate a variable name in the application program with
a particular default or configured device or board name.
The name used in the BDNAME$ argument must match
exactly the default or configured device or board name.
The number returned, referred throughout this manual as a
unit descriptor, is assigned here to the variable BD%, which
is used in all references to that device or board in GPIB
function calls.
IBFIND performs the equivalent of IBONL to open the
specified device or board and to initialize software
parameters to their default configuration settings. The
variable name selected should suggest the actual name of
the device or board in order to simplify programming effort.
If the IBFIND call fails, a negative number is returned in
place of the unit descriptor. The most probable reason for a
failure is that the string argument passed into IBFIND does
not match the default or configured device or board name.