Scpi language basics, Common terms used in this book – Agilent Technologies N9340A User Manual

Page 98

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6

SCPI Command Reference

96

N9340A User’s Guide

SCPI Language Basics

SCPI is an ASCII- based instrument command
language designed for test and measurement
instruments, with the goal of reducing automatic
test equipment (ATE) program development time.

SCPI accomplishes this goal by providing a
consistent programming environment for
instrument control and data usage. This consistent
programming environment is achieved by the use
of defined program messages, instrument
responses, and data formats across all SCPI
instruments.

By providing a consistent programming
environment, replacing one SCPI instrument with
another SCPI instrument in a system will usually
require less effort than with non- SCPI instrument.

SCPI is not a standard which completely provides
for interchangeable instrumentation. SCPI helps
move toward interchangeability by defining
instrument commands and responses, but not
functionality, accuracy, resolution, etc.

Common Terms used in this Book

Terms Description

Controller: Any computer used to communicate with an instrument. A

controller can be a personal computer (PC), a minicomputer, or a

plug-in card in a card cage. Some intelligent instruments can also

function as controllers.

Instrument: Any device that implements SCPI. Most instruments are electronic

measurement or stimulus devices, but this is not a requirement.
Similarly, most instruments use a GPIB or RS-232 or USB interface

for communication. The same concepts apply regardless of the

instrument function or the type of interface used.

Command: An instruction.

You combine commands to form messages that control

instruments to complete a specified task. In general, a command

consists of mnemonics (keywords), parameters and punctuation.

Query:

A special type of command. Queries instruct the instrument to

make response data available to the controller. Query keywords

always end with a question mark (?).

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