AMETEK Lx Series II Programming Manual - Manual (Page 16)

Programming Manual Lx \ Ls Series II
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2. Introduction to SCPI
SCPI (Standard Commands for Programmable Instruments) is a programming language for
controlling instrument functions over the IEEE-488. SCPI is layered on top of the hardware-portion
of IEEE 488.2. The same SCPI commands and parameters control the same functions in different
classes of instruments.
2.1 Conventions Used in This Manual
Angle brackets <> Items within angle brackets are parameter abbreviations. For
example, indicates a specific form of numerical data.
Vertical bar | Vertical bars separate alternative parameters. For example,
NORM | TEXT indicates that either "TEXT" or "NORM" can be used as a
parameter.
Square Brackets [] Items within square brackets are optional. The representation
[SOURce:]LIST means that SOURce: may be omitted.
Braces {} Braces indicate parameters that may be repeated zero or more
times. It is used especially for showing arrays. The notation <,B>
shows that parameter "A" must be entered, while parameter "B" may be
omitted or may be entered one or more times.
2.2 The SCPI Commands and Messages
2.2.1 Types of SCPI Commands
SCPI has two types of commands, common and subsystem.
Common commands generally are not related to specific operation but to
controlling overall AC source functions, such as reset, status, and synchronization. All common
commands consist of a three-letter mnemonic preceded by an
asterisk: *RST, *IDN?, *SRE 8
Subsystem commands perform specific AC source functions. They are organized
into an inverted tree structure with the "root" at the top. Some are
single commands while others are grouped within specific
subsystems.
Refer to appendix A for the AC source SCPI tree structure.
2.2.2 Types of SCPI Messages
There are two types of SCPI messages, program and response.
A program message consists of one or more properly formatted SCPI commands sent from
the controller to the AC source. The message, which may be sent at any time, requests the
AC source to perform some action.
A response message consists of data in a specific SCPI format sent from the AC source to
the controller. The AC source sends the message only when commanded by a program
message called a "query."