Agilent Technologies N3280A User Manual

4 - Introduction to Programming

 

 

SCPI (Standard Commands for Programmable Instruments) is a programming language for controlling
instrument functions over the GPIB. 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.

 

 

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, VOLT | CURR
indicates that either "VOLT" or "CURR" can be used as a parameter.

 

Square Brackets

[

]

 Items within square brackets are optional. The representation [SOURce:].
VOLTage 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 <A>{<,B>} shows that parameter "A"
must be entered, while parameter "B" may be omitted or may be entered one or
more times.

 

Parentheses

(

)

 Items within parentheses are used in place of the usual parameter types to specify a
channel list. The notation (@1:3) specifies a channel list that includes channels 1,
2, and 3. The notation (@1,3) specifies a channel list that includes only channels 1
and 3.

 

Computer

 font

 Computer font is used to show program lines in text.
TRIGger:ACQuire:SOURce BUS

 shows a program line.

 

 

SCPI has two types of commands, common and subsystem.

♦  Common commands generally are not related to specific operation but to controlling overall dc

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 dc source functions. They are organized into an inverted tree

structure with the "root" at the top. The following figure shows a portion of a subsystem command
tree, from which you access the commands located along the various paths. You can see the complete
tree in Appendix. D.

 

:OUTPut

[:STATe]

:OSCProtect

:PROTection

:CLEar

:STATus

:CONDition?

:OPERation

[:EVEN]?

[:STATe]

 Figure 4-1. Partial Command Tree