National Instruments FOUNDATION NI-FBUS Hardware And Software User Manual page 74

Chapter 6 NI-FBUS Function Reference
nifGetVFDList
Purpose
Gathers VFD information on a specified physical device.
Format
nifError_t
Input
ud
numBuffers
Output
numBuffers
info
Context
Physical device.
Description
nifGetVFDList
physical device.
If there are too few input buffers, or if the input buffer pointer is NULL, an error code is
returned, but the
In this case, no buffers contain valid data on output.
To determine how many list items are to be returned in the call, call the function twice.
The first time you call the function, set the
return an error stating that there were not enough buffers configured, and it will return a new
number for
numBuffers
data. When you call the function the second time, use this new parameter. By doing so, you
will allocate only as much memory as necessary.
The parameter has the following format:
info
typedef struct {
char vfdTag[TAG_SIZE +1];
char vendor[TAG_SIZE +1];
char model[TAG_SIZE +1];
NI-FBUS Hardware and Software User Manual
nifGetVFDList(
nifDesc_t ud,
nifVFDInfo_t *info,
uint16 *numBuffers)
The descriptor of the physical device for which to get the VFD list.
The number of buffers allocated in the
The number of VFDs actually in the device.
The VFD information.
gathers function block application VFD information from the specified
parameter is set to the total number of VFDs in the device.
numBuffers
. Use this new
parameter to 0. The function will
numBuffers
parameter to allocate memory for the
numBuffers
6-12
list.
info
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