Agilent Technologies E4440A User Manual

294 Chapter 5
Programming Fundamentals
SCPI Language Basics
Programming Fundamentals
Block Program Data
Some parameters consist of a block of data. There are a few standard
types of block data. Arbitrary blocks of program data can also be used.
<trace> Is an array of rational numbers corresponding to
displayed trace data. See FORMat:DATA for
information about available data formats.
A SCPI command often refers to a block of current trace
data with a variable name such as: Trace1, TRACE2, or
trace3, depending on which trace is being accessed.
<arbitrary block data> Consists of a block of data bytes. The first
information sent in the block is an ASCII header
beginning with #. The block is terminated with a
semi-colon. The header can be used to determine how
many bytes are in the data block. There are no units.
(You will not get block data if your data type is ASCII,
using FORMat:DATA ASCII command. Your data will be
comma separated ASCII values.
Block data example: suppose the header is #512320.
• The first digit in the header (5) tells you how many
additional digits/bytes there are in the header.
• The 12320 means 12 thousand, 3 hundred, 20 data
bytes follow the header.
• Divide this number of bytes by your current data
format (bytes/data point), either 8 (for real,64), or 4
(for real,32). For this example, if you’re using real64
then there are 1540 points in the block.
Putting Multiple Commands on the Same Line
Multiple commands can be written on the same line, reducing your code
space requirement. To do this:
• Commands must be separated with a semicolon (;).
• If the commands are in different subsystems, the key word for the
new subsystem must be preceded by a colon (:).
• If the commands are in the same subsystem, the full hierarchy of the
command key words need not be included. The second command can
start at the same key word level as the command that was just
executed.
SCPI Termination and Separator Syntax
A terminator must be provided when an instrument is controlled using
RS-232. There are several issues to be understood about choosing the

Agilent Technologies E4440A Specifications

General

Brand	Agilent Technologies
Model	E4440A
Category	Measuring Instruments
Language	English

Summary

2. Instrument Functions: A - L

2.1 AMPLITUDE / Y Scale

Controls display of amplitude data, including reference level and scaling.

2.7 FREQUENCY / Channel

2.8 Input/Output

3. Instrument Functions: M - O

3.1 Marker

Controls marker functions for measuring trace data points.

3.4 MEASURE (Spectrum Analysis Mode)

Provides access to measurement setup and configuration options.

3.6 MODE and Mode Setup

4. Instrument Functions: P - Z

4.1 Peak Search

Locates and analyzes peaks on the trace based on defined parameters.

4.2 Preset

4.5 Save

Saves analyzer states, traces, and screen data to storage.

4.7 SPAN / X Scale

Adjusts the displayed frequency range and X-axis scale.

4.8 SWEEP

Controls sweep time and mode for signal acquisition.

4.9 System

5. Programming Fundamentals

SCPI Language Basics

Introduces the SCPI programming language, keywords, syntax, and parameters.

Improving Measurement Speed

Provides techniques to optimize program execution and measurement speed.

Programming Command Compatibility Across Model Numbers and Across Modes

Using the LAN to Control the Instrument

Explains how to control the instrument using LAN connectivity.

Programming in C Using the VTL

6. Using the STATus System

Using the Status Registers

Common Using the STATus System IEEE Commands

STATus Subsystem

Explains the SCPI-defined instrument-status reporting structures and registers.

7. Menu Maps: Spectrum Analysis

FREQUENCY Channel Key (See page 143)

Input/Output Key (See page 151)

Marker Key (See page 167)

Details the menu structure for controlling marker functions on the trace.

Marker --> Key (See page 185)

Marker Fctn Key (See page 179)

MODE Key (See page 195)

Peak Search Key (See page 203)

Shows the menu flow for performing peak searches on trace data.

Preset Key (See page 211)

Print Setup Key (See page 215)

SPAN X Scale Key (See page 227)

Details the menu structure for adjusting span and X-axis scale.

Sweep Key (See page 231)

Shows the menu paths for controlling sweep time and mode.

System Key, 1 of 4 (See page 241)

Trace/View Key (See page 277)

Trig Key (See page 281)

Details the menu paths for setting trigger conditions for sweeps and measurements.