Argantix XDS 100-100, User And Programming Manual

Page: 80 / 116

User and Programming Manual
80 XDS Series
10 Introduction to SCPI
SCPI (Standard Commands for Programmable Instruments) is a programming language for
controlling instrument functions over the RS232 or IEEE 488 bus. The same SCPI commands and
parameters control the same functions in different classes of instruments. For example, you would
use the same MEAS:VOLT? command to measure the Power supply output voltage or the output
voltage of a SCPI-compatible Multimeter.
10.1 Conventions Used in This Manual
Angle brackets<> Items within angle brackets are parameter abbreviations. For example,
<NR1> indicates a specific form of numerical data.
Vertical bar Vertical bars separate alternative parameters. For example, 0 | 1 indicates
that either "0" or "1" can be used as a parameter.
Square Brackets[] Items within square brackets are optional. The representation
[SOURce:]VOLT means that SOURce: may be omitted.
Boldface font Boldface font is used to emphasize syntax in command definitions. CURR
<NRf> shows a command definition.
Upper case font Upper case font is used to show program lines in text. OUTP 1 shows a
program line.
10.2 The SCPI Commands and Messages
This paragraph explains the syntax difference between SCPI Commands and SCPI messages.
The power supply supports two types of commands, IEEE-488-2 common and SCPI subsystem
commands.
•
IEEE-488-2 common commands are generally not related to specific operations but to controlling
overall Power supply functions such as reset, status and synchronization. All common
commands consist of a three-letter mnemonic preceded by an asterisk:
*RST *IDN? *SRE 255
•
SCPI Subsystem commands perform specific Power supply 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.
You must include the root header in all commands sent
to the Power supply.
Refer to appendix A for the SCPI tree structure.
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 Power supply. The message, which may be sent at any time, requests the Power
supply to perform some action.
•
A response message consists of data in a specific SCPI format sent from the Power supply to the
controller. The Power supply sends the message only when commanded by a program message
called a "query."