Chapter 6
NI-FBUS Function Reference
©
National Instruments Corporation
6-55
NI-FBUS Hardware and Software User Manual
Using Interface Macros
This section contains tips for using the NI-FBUS Communications Manager interface macros.
These macros are defined in the header file
nifbus.h
.
As shown in Table 6-5, you can specify the parameter your application reads in the
name
parameter in the following ways:
•
To specify an object by index, use the
NIFB_INDEX
macro in the
nifbus.h
header file.
•
To specify an array or structure element by index and subindex, use the
NIFB_INDEX_SUBINDEX
macro.
•
If you already have a block descriptor, you can specify an object by its item ID with
the
NIFB_ITEM
macro, or you can specify a subelement by its item ID with the
NIFB_ITEM_SUBINDEX
macro.
Table 6-5.
Core Function Macros
Descriptor Type
You Have
Parameter Information
You Have
Macro to Use
Block Descriptor
Name
Normal Access by Name
Name and Subindex
NIFB_NAME_SUBINDEX
Relative Index within
the Block
NIFB_INDEX
Relative Index and Subindex
NIFB_INDEX_SUBINDEX
Device Description Item ID
NIFB_ITEM
Device Description Item ID
and Subindex
NIFB_ITEM_SUBINDEX
Non-Block Descriptor
Name
Normal Access Using
BLOCKTAG.PARAM
Format
Name and Subindex
NIFB_BLOCK_NAME_SUBINDEX
Relative Index within
the Block
NIFB_BLOCK_INDEX
Relative Index and Subindex
NIFB_BLOCK_INDEX_SUBINDEX
Device Description Item ID
NIFB_BLOCK_ITEM
Device Description Item ID
and Subindex
NIFB_BLOCK_ITEM_SUBINDEX