National Instruments FOUNDATION NI-FBUS Hardware And Software User Manual page 83

nifOpenVfd
Purpose
Returns a descriptor representing a Virtual Field Device (VFD).
Format
nifError_t
nifError_t
Input
ud
vfdTag
Output
out_ud
Context
Physical device.
Description
nifOpenVfd
within a physical device. You must pass a valid physical device descriptor to this function.
There are two ways to specify the VFD: by tag and by ordinal number. To open the VFD by
its tag, you must set the
Communications Manager returns an error if it finds more than one VFD with the same tag.
You can obtain the list of VFD tags within a specified physical device with a call to
nifGetVFDList
To open the VFD by its ordinal number, use the
application in a physical device has the ordinal number zero. Notice that the Management
VFDs are not included in the ordinal numbering scheme.
© National Instruments Corporation
nifOpenVfd (
nifDesc_t ud,
char *vfdTag,
nifDesc_t *out_ud)
nifOpenVfd (
nifDesc_t ud,
NIFB_ORDINAL(n),
nifDesc_t *out_ud)
A valid physical device descriptor.
The tag of the VFD. To access by ordinal number within a
physical device, use the
header file.
A descriptor for the VFD you request.
returns a descriptor for the VFD you specify. More than one VFD can reside
parameter to the current tag of the VFD. The NI-FBUS
vfdTag
.
Chapter 6
ORDINAL
NIFB_ORDINAL
6-21 NI-FBUS Hardware and Software User Manual
NI-FBUS Function Reference
macro in the
nifbus.h
macro. The first VFD of your