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Chapter 3
Understanding the NI-488.2M Software
This chapter introduces you to two of the programming options of the
NI-488.2M software. Specifically, the NI-488.2 routines and NI-488
functions are presented to guide you as to which function set to use.
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The NI -488.2 routines directly adhere to the Controller sequences and
protocols defined in the IEEE 488.2 1992 standard. They accept a
single device address or a list of device addresses as an input parameter
so that functions can address multiple instruments easily. These
routines give you all the advantages of IEEE 488.2.
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The NI -488 functions have existed for many years and are the industry
standard functions for GPIB applications. They have both high-level,
device functions and low-level, board functions.
This chapter also discusses programming issues such as global variables,
error codes, read and write termination, and C programming preparations
that are common to both the NI-488.2 routines and NI-488 functions.
Introduction to the NI-488.2 Routines
A new set of NI-488.2 routines have been added to the NI-488.2M software
to take advantage of the IEEE 488.2 1992 standard. The NI-488.2 routines
are described in Chapter 4, NI-488.2M Software Characteristics and
Routines. These routines are completely compatible with the Controller
sequences and protocols defined in the IEEE 488.2 1992 standard.
IEEE 488.2 is the standard upon which the new generation of test systems
will be built because it enhances system compatibility and configurability
by defining data formats, status reporting, Controller capabilities and
commands, and a general command set to which all IEEE 488.2 instruments
must adhere. IEEE 488.2 is also the basis of the Standard Commands for
Programmable Instrumentation (SCPI), so all SCPI instruments must be
IEEE 488.2 compatible. The NI-488.2 routines address these system
programming benefits of IEEE 488.2.
© National Instruments Corp.
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NI-488.2M Reference Manual