Rohde&Schwarz ESR-K55 User Manual

R&S®ESR-K55
Real-Time Analysis
User Manual

(;ÙÔØ2)

1175707402
Version 06

This manual applies to the following R&S®ESR options:

●

R&S®ESR-K55 (Realtime Analysis)

The contents of this manual correspond to the following R&S®ESR models with firmware version 3.66 or
higher:

●

R&S ESR3

●

R&S ESR7

●

R&S ESR26

© 2021 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: [phone] - 0
Email: [e-mail]
Internet: www.rohde-schwarz.com
Subject to change – data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
Trade names are trademarks of the owners.

1175.7074.02 | Version 06 | R&S®ESR-K55

Throughout this manual, products from Rohde & Schwarz are indicated without the ® symbol , e.g. R&S®ESR is indicated as
R&S ESR.

R&S®ESR-K55

1.1 Conventions Used in the Documentation...................................................................5

1.2 How to Use the Help System........................................................................................6

2.1 Receiver Mode...............................................................................................................8

2.2 Spectrum Mode............................................................................................................. 8

2.3 I/Q Analyzer Mode......................................................................................................... 9

2.4 Real Time Mode.............................................................................................................9

2.5 Measurement Mode Root Menus (HOME Key)........................................................... 9

Contents

Contents

1 Preface.................................................................................................... 5

2 Measurement Modes..............................................................................8

3 Measurements and Result Displays...................................................10

3.1 The Realtime Spectrum Result Display.................................................................... 10

3.2 The Spectrogram Result Display...............................................................................12

3.3 The Persistence Spectrum Result Display............................................................... 24

4 Measurement Basics........................................................................... 33

4.1 Data Acquisition and Processing in a Realtime Analyzer.......................................33

4.2 Configuring Realtime Measurements........................................................................35

4.3 Triggering Measurements.......................................................................................... 38

4.4 Using Markers............................................................................................................. 44

4.5 Detector Overview.......................................................................................................46

4.6 ASCII File Export Format............................................................................................47

5 Configuration........................................................................................50

5.1 Result Display Selection............................................................................................ 50

5.2 Result Display Configuration.....................................................................................51

5.3 Common Measurement Settings............................................................................... 53

6 Analysis................................................................................................ 65

6.1 Working with Traces................................................................................................... 65

6.2 Using Markers............................................................................................................. 68

7 Remote Control Commands................................................................75

7.1 Selecting the Operating Mode................................................................................... 75

3User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

7.2 Measurements and Result Displays..........................................................................76

7.3 Configuration...............................................................................................................88

7.4 Analysis......................................................................................................................111

7.5 Status Registers........................................................................................................149

Contents

List of commands.............................................................................. 158

Index....................................................................................................163

4User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

1 Preface

1.1 Conventions Used in the Documentation

1.1.1 Typographical Conventions

Preface

Conventions Used in the Documentation

This chapter provides safety-related information, an overview of the user documenta­tion and the conventions used in the documentation.

The following text markers are used throughout this documentation:

Convention Description

"Graphical user interface ele­ments"

[Keys] Key and knob names are enclosed by square brackets.

Filenames, commands,
program code

Input Input to be entered by the user is displayed in italics.

Links Links that you can click are displayed in blue font.

"References" References to other parts of the documentation are enclosed by quota-

All names of graphical user interface elements on the screen, such as
dialog boxes, menus, options, buttons, and softkeys are enclosed by
quotation marks.

Filenames, commands, coding samples and screen output are distin­guished by their font.

tion marks.

1.1.2 Conventions for Procedure Descriptions

When operating the instrument, several alternative methods may be available to per­form the same task. In this case, the procedure using the touchscreen is described.
Any elements that can be activated by touching can also be clicked using an addition­ally connected mouse. The alternative procedure using the keys on the instrument or
the on-screen keyboard is only described if it deviates from the standard operating pro­cedures.

The term "select" may refer to any of the described methods, i.e. using a finger on the
touchscreen, a mouse pointer in the display, or a key on the instrument or on a key­board.

1.1.3 Notes on Screenshots

When describing the functions of the product, we use sample screenshots. These
screenshots are meant to illustrate as many as possible of the provided functions and

5User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

1.2 How to Use the Help System

Preface

How to Use the Help System

possible interdependencies between parameters. The shown values may not represent
realistic usage scenarios.

The screenshots usually show a fully equipped product, that is: with all options instal­led. Thus, some functions shown in the screenshots may not be available in your par­ticular product configuration.

Calling context-sensitive and general help

► To display the general help dialog box, press the [HELP] key on the front panel.

The help dialog box "View" tab is displayed. A topic containing information about
the current menu or the currently opened dialog box and its function is displayed.

For standard Windows dialog boxes (e.g. File Properties, Print dialog etc.), no context­sensitive help is available.

► If the help is already displayed, press the softkey for which you want to display

help.
A topic containing information about the softkey and its function is displayed.

If a softkey opens a submenu and you press the softkey a second time, the submenu
of the softkey is displayed.

Contents of the help dialog box

The help dialog box contains four tabs:

●

"Contents" - contains a table of help contents

●

"View" - contains a specific help topic

●

"Index" - contains index entries to search for help topics

●

"Zoom" - contains zoom functions for the help display

To change between these tabs, press the tab on the touchscreen.

Navigating in the table of contents

●

To move through the displayed contents entries, use the [UP ARROW] and [DOWN
ARROW] keys. Entries that contain further entries are marked with a plus sign.

●

To display a help topic, press the [ENTER] key. The "View" tab with the corre­sponding help topic is displayed.

●

To change to the next tab, press the tab on the touchscreen.

6User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Preface

How to Use the Help System

Navigating in the help topics

●

To scroll through a page, use the rotary knob or the [UP ARROW] and [DOWN
ARROW] keys.

●

To jump to the linked topic, press the link text on the touchscreen.

Searching for a topic

1. Change to the "Index" tab.

2. Enter the first characters of the topic you are interested in. The entries starting with
these characters are displayed.

3. Change the focus by pressing the [ENTER] key.

4. Select the suitable keyword by using the [UP ARROW] or [DOWN ARROW] keys
or the rotary knob.

5. Press the [ENTER] key to display the help topic.

The "View" tab with the corresponding help topic is displayed.

Changing the zoom

1. Change to the "Zoom" tab.

2. Set the zoom using the rotary knob. Four settings are available: 1-4. The smallest
size is selected by number 1, the largest size is selected by number 4.

Closing the help window

► Press the [ESC] key or a function key on the front panel.

7User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

2 Measurement Modes

Measurement Modes

Spectrum Mode

The R&S ESR provides several measurement modes for different analysis tasks.
When you activate a measurement mode, a new measurement channel is created. The
channel determines the settings for that measurement mode. Each channel is dis­played in a separate tab on the screen.

SCPI command:

INSTrument[:SELect] on page 76

To change the measurement mode

1. Press the MODE key.
A menu with the currently available measurement modes is displayed.

2. To activate a different mode, press the corresponding softkey.

2.1 Receiver Mode

In Receiver mode, the R&S ESR measures the signal level at a particular frequency. It
also provides tools (e.g. detectors or bandwidths) necessary to measure the signal
according to EMC standards. The Receiver mode is the default mode of the R&S ESR.

The R&S ESR also provides function for IF analysis if you have equipped your
R&S ESR with firmware application R&S ESR-K56. IF analysis is not a separate mea­surement mode but is integrated into the Receiver mode.

For more information on functionality available for the Receiver mode see the docu­mentation of the R&S ESR.

SCPI command:

INST REC

2.2 Spectrum Mode

In Spectrum mode the provided functions correspond to those of a conventional spec­trum analyzer. The analyzer measures the frequency spectrum of the RF input signal
over the selected frequency range with the selected resolution and sweep time, or, for
a fixed frequency, displays the waveform of the video signal.

The Spectrum mode also provides spectrogram measurements. The spectrogram is
not a separate measurement mode, but rather a trace evaluation mode. Note also that
the Spectrogram available in Spectrum mode is independent of that available in real
time mode. It provides similar functionality but uses different data acquisition methods.

For more information on functionality available for the Receiver mode see the docu­mentation of the R&S ESR.

8User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

2.3 I/Q Analyzer Mode

2.4 Real Time Mode

Measurement Modes

Measurement Mode Root Menus (HOME Key)

SCPI command:

INST SAN

The I/Q Analyzer mode provides measurement and display functions for digital I/Q sig­nals.

For more information on functionality available for the Receiver mode see the docu­mentation of the R&S ESR.

In Real Time mode, the R&S ESR performs measurements in the frequency spectrum
of a test signal without losing any signal data. You can evaluate the measurement
results in several result displays that are designed for the realtime analysis and com­plement one another.

Real Time analysis is available with firmware application R&S ESR-K55 and hardware
option R&S ESR-B50.

SCPI command:

INST RTIM

2.5 Measurement Mode Root Menus (HOME Key)

The HOME key provides a quick access to the root menu of the current measurement
mode.

9User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

3 Measurements and Result Displays

Measurements and Result Displays

The Realtime Spectrum Result Display

The R&S ESR, when operated in realtime mode has several result displays. You can
select a result display with one of the softkeys in the "Home" menu that you can
access via the
figuration" dialog box that you can open with the "Display Config" softkey.

The dialog box has four tabs (Screen A through D) to configure up to four result dis­plays. In the default state, Screen A and Screen B are active and show the realtime
spectrum and the spectrogram respectively. You can, however, customize the display
of the R&S ESR as you like.

You can add or remove a result display by checking or unchecking the "Screen Active"
item and define the corresponding result display with the radio button below.

The "Predefined" tab contains customized screen layouts. Some of those are already
provided with the firmware. You can also add your own screen layouts to the list in
order to avoid configuring the screen every time you start the R&S ESR.

The "Add" button adds a new screen layout to the list. Pressing the "Apply" button
applies the screen layout you have selected and the "Remove" button removes the
selected layout from the list. If you want to restore the default configurations, press the
"Restore" button.

key. An alternative way to configure the display is the "Display Con-

CALCulate<n>:FEED on page 77

● The Realtime Spectrum Result Display.................................................................. 10

● The Spectrogram Result Display............................................................................ 12

● The Persistence Spectrum Result Display..............................................................24

3.1 The Realtime Spectrum Result Display

In principle, the realtime spectrum result display looks just like the result display of a
conventional spectrum analyzer. It is a two-dimensional diagram that contains a line
trace that shows the power levels for each frequency for a particular bandwidth or span
with the horizontal and vertical axis representing frequency and amplitude. The big dif­ference to a conventional spectrum analyzer is the way the realtime spectrum analyzer
gets its data.

CALCulate<n>:FEED on page 77

Displaying the data

The evaluation of the final displayed results again is standard spectrum analyzer func­tionality. The R&S ESR combines a spectrum consisting of 801 measurement points
and adjusts them to the number of pixels that the display has. The way it evaluates the
final results that you see on the display, depends on the type of detector that you have
set.

For more information refer to Chapter 4.5, "Detector Overview", on page 46.

10User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

]

FFT

[.]SweepTime[N

sec

000250sec 

3.1.1 Screen Layout of the Realtime Spectrum Result Display

Measurements and Result Displays

The Realtime Spectrum Result Display

As the number of FFTs is considerably higher than the sweep time, the R&S ESR com­bines several FFTs in one trace. The number of FFTs combined in a trace at a band­width of 40 MHz depends on the sweep time and is according to the following formula.

1

= Window number: shows the window of the result display (A through D)
2 = Trace information: includes trace mode and detector
3 = Trace diagram
4 = Markers: Mx for normal markers and Dx for deltamarkers
5 = Marker information: trace number, marker frequency and corresponding amplitude
6 = Realtime trace (yellow line)
7 = Center frequency
8 = Span

3.1.2 Applications of the Realtime Spectrum

Just like the spectrum results of a conventional analyzer, you can find many applica­tions for the realtime spectrum result display.

If you use it as a standalone result display, the advantage of the realtime spectrum
result display is the ability to monitor the spectrum without losing information.

The best way to use this feature, however, is to combine the realtime spectrum result
display with the spectrogram result display in split screen mode. The spectrogram
shows the results with a large history depth, but is not suited for detailed analysis of
the data. You can, however, select a particular frame in the spectrogram's history with
the marker and recall the spectrum of that frame for further and more detailed and full
analysis of the measured signal.

The picture below shows that application. The realtime spectrum is not the currently
measured spectrum, but the one that was measured at the time of marker 1. The real­time spectrum corresponds to the spectrogram frame of the marker position.

11User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

Figure 3-1: Simultaneous display of realtime spectrum and spectrogram showing a past spectrum

3.2 The Spectrogram Result Display

The spectrogram result display shows the spectral density of a signal in the frequency
domain and over time simultaneously. It provides an overview of the spectrum over
time and so allows for an easy detection of anomalies and interfering signals.

Like the realtime spectrum, the horizontal axis represents the frequency span. The ver­tical axis represents time. Time in the spectrogram runs chronologically from top to bot­tom. Therefore, the top of the diagram is the most recently recorded data. The spectro­gram also shows the power levels for every realtime spectrum trace. To display the
level information, the R&S ESR maps different colors to each power level that has
been measured. The result is therefore still a two dimensional diagram.

CALCulate<n>:FEED on page 77

The process to get the spectrogram result display is as follows:

●

capturing the data from the realtime trace

●

coloring the results.

●

processing the data

The stages occur at the same time.

12User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

Capturing the data

The spectrogram uses the realtime spectrum traces as its data basis. The data capture
process is therefore the same as that of the realtime spectrum result display.

For more information, see Chapter 4.1, "Data Acquisition and Processing in a Realtime

Analyzer", on page 33

After the data has been captured, the R&S ESR transforms the data of the realtime
spectrum into the spectrogram result display.

Coloring the results

To get the final looks of the spectrogram, the R&S ESR applies colors to to visualize
the power levels in a two dimensional diagram.

Each color in the spectrogram corresponds to a particular power level that is shown in
the color map in the title bar of the result display. The color the R&S ESR assigns to
each power level depends on:

●

the color scheme you have selected

●

the (customized) color mapping settings

In the default configuration, the R&S ESR displays low power levels in 'cold' colors
(blue, green etc.) and higher power levels in 'warm' colors (red, yellow etc.).

For more information, see Chapter 3.2.3.3, "Customizing the Color Mapping",
on page 20

Displaying the results

Now that the data is available, the R&S ESR processes the data to display it in the
spectrogram result display.

To understand the structure and contents of the spectrogram, it is best to activate the
realtime spectrum result display in combination with the spectrogram, as the data that
is shown in the spectrogram is always based on the data of the trace in the realtime
spectrum result display.

The spectrogram is made up out of a number of horizontal lines, each one pixel high,
that are called (time) frames. Like the trace of the realtime spectrum, a spectrogram
frame contains several FFTs. The exact number of FFTs contained in a frame depends
on the sweep time. As the sweep time also sets the length of a realtime spectrum
trace, by default a frame in the spectrogram always corresponds to exactly one trace in
single sweep mode in the realtime spectrum result display. You can change this ratio
by changing the sweep count.

In the default state, a frame is added to the spectrogram after each sweep. As the
spectrogram in the R&S ESR runs from top to bottom, the outdated frame(s) move
down one position, so that the most recently recorded frame is always on top of the
diagram.

The number of frames the R&S ESR can display simultaneously is only limited by the
vertical screen size. The number of frames the R&S ESR stores in its history memory
is bigger. It depends on the history depth you have set, with the maximum being

100.000. You can then navigate to any of the frames stored in the history buffer.

13User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

3.2.1 Screen Layout

Measurements and Result Displays

The Spectrogram Result Display

Note that the R&S ESR stores just the trace information in its memory, not the I/Q data
itself.

For more information, see Chapter 3.2.3.1, "Working with the Spectrogram History",
on page 15.

By default, the currently shown realtime spectrum trace corresponds to the spectro­gram frame that has been recorded last. In single sweep mode, you can, however,
recall the spectrums up to a maximum of 100.000 frames and evaluate them at a later
time. The number of spectrums available depends on the history depth.

1

= Window number: shows the window of the result display (A through D)
2 = Trace information: includes trace mode and detector
3 = Color Map
4 = Spectrogram
5 = Marker indicator: shows the vertical position of the active marker
6 = Markers and deltamarkers
7 = Center frequency
8 = Span
9 = Time stamp information; if time stamp is inactive this shows the shows the currently active frame instead

3.2.2 Applications of the Spectrogram Result Display

The spectrogram provides an easy way to monitor the changes of a signal's frequency
and amplitude over time. Typically, it is used for measurements in which time is a fac­tor. However, there are a lot of applications you could think of.

A typical applications of a spectrogram is the monitoring of telecommunications sys­tems that are based on frequency hopping techniques, e.g. GSM. Using the spectro­gram, you can see at a glance whether slots are allocated correctly or not. In addition,
the result display also provides information on the time a particular channel is in use.

Again in telecommunications systems that use frequency hopping techniques, you can
use the spectrogram to monitor the settling time to a new frequency after the channel
switching.

14User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

3.2.3 Configuring the Spectrogram

3.2.3.1 Working with the Spectrogram History

Measurements and Result Displays

The Spectrogram Result Display

The spectrogram is also suited for more general measurement tasks like measuring
the settling time of a DUT or the detection of the time and statistical frequency of inter­fering signals.

The spectrogram has two distinctive features: information over a period of time and the
colors. That means that it is important that you can customize various things concern­ing these two features.

TRACe<n>[:DATA] on page 115

MMEMory:STORe:SGRam on page 86

In realtime mode, the spectrogram provides a record of the spectrum without gaps.
Because the R&S ESR stores the history of the spectrum in its memory, you can ana­lyze the data in detail at a later time by recalling one of the spectrums in the spectro­gram history.

Defining the History Depth

The "History Depth" softkey defines the number of frames that the R&S ESR stores in
its memory. The maximum history depth is 100.000 frames.

It is possible to recall the realtime traces to any of the frames that the R&S ESR has in
its memory.

For more information, see

●

Chapter 3.1.2, "Applications of the Realtime Spectrum", on page 11

●

Chapter 3.2.2, "Applications of the Spectrogram Result Display", on page 14

●

CALCulate<n>:SGRam:HDEPth on page 84

Defining a Frame Count

The frame count defines the number of traces the R&S ESR plots in the spectrogram
result display in a single sweep. The maximum number of possible frames depends on
the history depth.

The sweep count, on the other hand, determines how many sweeps are combined in
one frame in the spectrogram, i.e. how many sweeps the R&S ESR performs to plot
one trace in the Spectrogram result display.

You can set the frame count with the "Frame Count" softkey which is available in single
sweep mode.

CALCulate<n>:SGRam:FRAMe:COUNt on page 83

15User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

Selecting a Frame

To get more information, you can select any frame that is stored in the memory of the
R&S ESR with the "Select Frame" softkey. Depending on whether you have activated a
time stamp or not, you select the frame either by time in seconds from the most recent
recorded frame (time stamp On) or by directly entering the frame number you'd like to
see (time stamp Off).

To select a specific frame, the R&S ESR has to be in single sweep mode.

CALCulate<n>:SGRam:FRAMe:SELect on page 83

Using the Time Stamp

The time stamp shows the time information of the selected frame. The length of one
frame corresponds to the sweep time.

If the time stamp is active, the time stamp shows the time and date the selected frame
was recorded. To select a specific frame, you have to enter the time in seconds, rela­tive to the frame that was recorded last. An active time stamp is the default configura­tion.

If you deactivate the time stamp with the "Time Stamp (On Off)" softkey, the time infor­mation is an index. The index is also relative to the frame that was recorded last, which
has the index number 0. The index ends with a negative number that corresponds to
the history depth. To select a specific frame, you have to enter the index number of the
frame you want to analyze.

CALCulate<n>:SGRam:TSTamp[:STATe] on page 85

CALCulate<n>:SGRam:TSTamp:DATA? on page 84

Exporting the Spectrogram Data

The R&S ESR allows you to export the spectrogram data to an ASCII file.

When you export the spectrogram to an ASCII file, the R&S ESR writes the complete
contents in its memory to an ASCII file. The amount of data depends on the history

depth.

To export the spectrogram, the spectrogram window has to be in focus (blue frame). To
perform the export itself, use the "ASCII Trace Export" softkey in the "Trace" menu.

File size

Depending on the contents of the capture buffer, the export may take some time and
the size of the ASCII file may be very large.

Clearing the Spectrogram

If you need to restart the spectrogram, you can clear the memory of the R&S ESR with
the "Clear Spectrogram" softkey at any time.

It is also possible to clear the spectrogram after each sweep automatically if you are in
single sweep mode. You can do so with the "Continue Frame (On Off)" softkey. If it is

16User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

3.2.3.2 Zooming into the Spectrogram

Measurements and Result Displays

The Spectrogram Result Display

active, the spectrogram keeps filling up with data after a single sweep. If inactive, how­ever, the R&S ESR clears the spectrogram after every single sweep.

CALCulate<n>:SGRam:CLEar[:IMMediate] on page 82

CALCulate<n>:SGRam:CONT on page 82

For further and more detailed analysis of the data you have captured, the R&S ESR
provides a zoom.

The zoom is available for the spectrogram result display, but has effects on other result
displays. The spectrogram has to be active and selected (blue border) for the zoom to
work.

You can activate the zoom with the
rectangle on the touchscreen. When you draw the zoom area, its boundaires are
shown as a dashed line. The R&S ESR stops the live measurement and enlargens the
area you have defined. The definition of the color map remains the same.

Inside the zoom area, you can use the spectrogram functionality as usual (like frame
selection or scrolling through the spectrogram).

For quick comparisons of the zoomed spectrogram and the unzoomed one, you can
use the "Replay Zoom (On Off)" softkey in the "Meas" menu.

Zooming into the spectrogram causes the R&S ESR to reprocess and reevaluate the
data that has been measured previously and stored in the R&S ESR memory. The
zoom also reduces the sweep time and/or resolution bandwidth and span. This in turn
improves the resolution of the data (while a graphical zoom merely interpolates the
data and thus reduces the resolution).

icon and define the zoom area by drawing a

17User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

Because the zoom is based on data that has already been captured, the zoom also
allows for faster sweep times (and thus spans) than those possible during live mea­surements (which are limited to 100 µs).

As mentioned above, selecting an area in the spectrogram to zoom into changes the
sweep time and span (and thus the start and stop frequencies of the diagrams). It may
also change the center frequency. The magnitude of the change depends on the size
of the zoom area. If the zoom is already active, this mechanism also works the other
way round. You can change the zoom factor by changing the sweep time or the span.

Zoom restrictions

Principally, the zoom is available for all measurement situations, whether you measure
continuously, in single sweep mode or use a trigger. However, possible zoom areas are
restricted by the size of the memory (4 seconds). If it is not possible to zoom into a
spectrogram area, the R&S ESR colors that area in a darker color when you touch it.

The zoom factor is restricted to 10% of the original span of the frequency axis.

18User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

In addition, the zoom is also restricted by the original bandwidth or span you have set.
Zooming into areas that are outside this bandwidth is not possible.

Note also that zoom availability depends on the trigger mode. Zooming while the mea­surement is running is possible only in Free Run mode. For all other trigger modes,
you have to wait until the measurement is paused.

Effects on other result displays

Zooming has an effect on the realtime spectrum result display. All other result displays
are unaffected.

●

The R&S ESR updates the range of horizontal axis of the realtime spectrum
according to the zoomed (new) spectrogram span. The range has an effect on the
start, stop and center frequency as well as the span.
The realtime spectrum still shows the spectrum of the currently selected spectro­gram frame.

Updates in the result displays only take effect if they have been active while the spec­trogram data has been reevaluated.

DISPlay:WINDow[:SUBWindow]:ZOOM:AREA on page 77

DISPlay:WINDow[:SUBWindow]:ZOOM:STATe on page 78

19User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

3.2.3.3 Customizing the Color Mapping

Measurements and Result Displays

The Spectrogram Result Display

Colors are an important part of the both the persistence spectrum and the spectro­gram. Therefore, the R&S ESR provides various ways to customize the display for best
viewing results.

You can access the Color Mapping dialog via the "Color Mapping" softkey or by tap­ping on the color map. The dialog looks and works similar for the histogram and the
spectrogram, only the the scaling or unit of the color map is different. For the persis­tence spectrum the R&S ESR maps the colors to percentages, for the spectrogram it
maps power levels (dBm). In addition, the dialog box of the persistence spectrum
offers a truncate function.

1

= Color map: shows the current color distribution

2 = Preview pane: shows a preview of the histogram / spectrogram with any changes that you make to the

color scheme
3 = Color curve pane: graphic representation of all settings available to customize the color scheme
4 = Color curve in its linear form
5 = Color range start and stop sliders: define the range of the color map; percentages for the histogram or

amplitudes for the spectrogram
6 = Color curve slider: adjusts the focus of the color curve
7 = Histogram: shows the distribution of measured values
8 = Scale of the horizontal axis (value range): in the spectrogram this is linear, in the histogram it is the

function of the density
9 = Color range start and stop: numerical input to define the range of the color map
10 = Color curve: numerical input to define the shape of the color curve
11 = Color scheme selection
12 = Truncate: if active, only shows the results inside the value range; only available for the persistence

spectrum

20User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

13 = Auto button: automatically sets the value range of the color map
14 = Default button: resets the color settings
15 = Close button: closes the dialog box

Setting the Color Scheme

Before adjusting the details of the color map, you should select the color scheme you
are most comfortable with. You can select from four different color schemes:

●

The "Hot" color scheme shows the results in colors ranging from blue to red. Blue
colors indicate low probabilities or levels respectively. Red colors indicate high
ones.

●

The "Cold" color scheme shows the results in colors ranging from red to blue. Red
colors indicate low probabilities or levels respectively. Blue colors indicate high
ones.
The "Cold" color scheme is the inverse "Hot" color scheme.

●

The "Radar" color scheme shows the colors ranging from black over green to light
turquoise with shades of green in between. Dark colors indicate low probabilities or
levels respectively. Light colors indicate high ones.

●

The "Grayscale" color scheme shows the results in shades of gray. Dark grays indi­cate low probabilities or levels respectively. Light grays indicate high ones.

If a result lies outside the defined range of the color map, it is colored in black at the
lower end of the color range. On the upper end of the color range it is always the light­est color possible, regardless of differences in amplitude (e.g. black and blue in case of
the "Cold" scheme).

DISPlay:WINDow:SGRam:COLor[:STYLe] on page 87

DISPlay:WINDow:SGRam:COLor:DEFault on page 87

Defining the Range of the Color Map

The current configuration could be a color map that you can optimize for better visuali­zation of the measured signal, e.g. if the results cover only a small part of the color
map. In the resulting trace, it would be hard to distinguish between values that are
close together.

There are several ways to optimize the distribution of the colors over the results and
then get the best viewing results.

Note that the following examples are based on the "Hot" color scheme and the spectro­gram. Color settings in the histogram are the same with the exception of the unit of the

21User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

color map that is % in the histogram. If something applies to the spectrogram only,
you'll find a note at that place.

The easiest way to adjust the colors is to use the color range sliders in the "Color Map­ping" dialog.

In the histogram that is in the background of the color curve pane (grey bars), you can
observe the distribution of measurement results. If no significant shifts in result distribu­tion occur after evaluating this for a time, you can adjust the color map to the overall
shape of the measurement results. To do so and still cover the whole signal, move the
sliders in a way that the first and last bar of the histogram are still inside the range. You
can optimize the display further, if you suppress the noise by excluding the lower 10 to
20 dB of the distribution. Note that the color map has to cover at least 10% of the
range of the horizontal axis.

Alternatively, you can set the range in the numeric input field. For the spectral histo­gram, you enter the percentages as they are plotted on the horizontal axis and dis­played in the spectral histogram itself. For the spectrogram however, you have to enter
the distance from the right and left border as a percentage.

Example:

The color map starts at -100 dBm and ends at 0 dBm (i.e. a range of 100 dB). You,
however, want the color map to start at -90 dBm. To do so, you have to enter 10% in
the Start field. The FSVR shifts the start point 10% to the right, to -90 dBm.

In the spectrogram, cutting the range as far as possible is also a good way if you want
to observe and put the focus on signals with a certain amplitude only. Then, only those
signal amplitudes that you really want see are displayed. The rest of the display
remains dark (or light, depending on the color scheme). It is also a good way to elimi­nate noise from the display. In the spectrogram you can do this easily by excluding the
corresponding power levels at the low end of the power level distribution.

In the histogram, cutting down the color range is also a good way to eliminate unwan­ted signal parts. Very frequent level and frequency combinations are most likely noise,
so cutting them away means that the color resolution for all other combinations is
enhanced and makes it more easy to detect, for example, weak and rare signals.

The persistence spectrum provides an additional truncate function. If active, all values
that are outside the color range are no longer displayed in the histogram.

22User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Spectrogram Result Display

Figure 3-2: Spectrogram that shows the peaks of a pulsed signal only

Adjusting the reference level and level range

Changing the reference level and level range also affects the color scheme in the
spectrogram.

Make sure, however, that you never adjust in a way that could overload the R&S ESR.
For more information, see AMPT menu

DISPlay:WINDow:SGRam:COLor:LOWer on page 87

DISPlay:WINDow:SGRam:COLor:UPPer on page 87

Defining the Shape of the Color Curve

Now that the color scheme and range of the color map suit your needs, you can
improve the color map even more by changing the shape of the color curve.

The color curve is a tool to shift the focus of the color distribution on the color map. By
default, the color curve is linear. The color curve is linear, i.e. the colors on the color
map are distributed evenly. If you shift the curve to the left or right, the distribution
becomes non-linear. The slope of the color curve increases or decreases. One end of
the color palette then covers a large amount results while the the other end distributes
a lot of colors on relatively small result range.

You can use this feature to put the focus on a particular region in the diagram and to be
able to detect small variations of the signal.

23User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Persistence Spectrum Result Display

Example:

Figure 3-3: Linear color curve shape = 0

The color map above is based on a linear color curve. Colors are distributed evenly
over the complete result range.

Figure 3-4: Non-linear color curve shape = -0.5

After shifting the color curve to the left (negative value), more colors cover the range
from -105.5 dBm to -60 dBm (blue, green and yellow). In the color map based on the
linear color curve, the same range is covered by blue and a few shades of green only.
The range from -60 dBm to -20 dBm on the other hand is dominated by various shades
of red, but no other colors. In the linear color map, the same range is covered by red,
yellow and a few shades of green.

The result of shifting the color curve is that results in a particular result range (power
levels in case of the spectrogram and densities in the case of the spectral histogram)
become more differentiated.

You can adjust the color curve by moving the middle slider in the color curve pane to a
place you want it to be. Moving the slider to the left shifts the focus in the direction of
low values. Most of the colors in the color map are then concentrated on the low power
levels (spectrogram) or densities (histogram), while only a few colors cover the upper
end of the color map or high power levels or densities. Moving the slider to the right
shifts the focus to the higher amplitudes or densities.

Alternatively, you can enter the shape of the color curve in the corresponding input field
below the color curve pane. A value of 0 corresponds to a linear shape, negative val­ues up to -1 shift the curve to the left, positive values up to 1 shift the curve to the right.

DISPlay:WINDow:SGRam:COLor:SHAPe on page 87

3.3 The Persistence Spectrum Result Display

The persistence spectrum is a two dimensional histogram that shows the statistical fre­quency of any frequency and level combinations for every pixel on the display ('hits'
per pixel). As the number of FFTs used to create the histogram is very large, you can
also look at it as a probability distribution.

Note that the word 'density' in this context means how frequent a certain level and fre­quency combination has occured during the measurement.

In principle, the result display looks just like that of a conventional spectrum analyzer
with the horizontal and vertical axis representing the frequency and level respectively.
Unlike the trace in a conventional spectrum analyzer, the persistence spectrum

24User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

]

FFT

[.]y[GranularitN

sec

000250sec 

Measurements and Result Displays

The Persistence Spectrum Result Display

includes a third type of information (a virtual z-axis). This virtual axis represents the
number of hits that occured during a particular period of time. This would result in a
three dimensional diagram with the height of each bar on the z-axis representing the
number of hits per pixel. This makes the result display a (spectral) histogram.

However, in the final display of the results the R&S ESR still shows the trace in two
dimensions with the number of hits represented by different shades of color. The result
is a trace that covers an area instead of a line trace as you know it from the realtime
spectrum result display, for example.

CALCulate<n>:FEED on page 77

For better orientation, the R&S ESR also always shows the realtime spectrum line
trace in the histogram as a white line superimposed over the histogram.

You can turn off the realtime trace by setting the trace mode for that one to "Blank".

To get the final result display for a single frame, the R&S ESR sequentially runs
through a number of processing steps:

●

collecting the data

●

evaluating the data

●

calculating relative values of the data

●

coloring the results.

The stages occur at the same time.

Collecting the data

The persistence spectrum that the R&S ESR displays at any time always represents
the data it has collected in exactly one frame. That means that in single sweep mode, it
shows the data of one frame after it has finished the sweep. The number of FFTs in
one frame is variable and depends on the sweep time that you have set. You can cal­culate the number of FFTs in each frame for a 40 MHz bandwidth with the following
formula:

Example:

If you have set a granularity of 0.5 seconds, the number of FFTs that a frame (and the
trace) contains is 125.000.

Note that this number refers to the instantenuous histogram. If you work with an active
persistence, you can also see the shadows of past histograms on the display. The per­sistence functionality displays all spectrums that were captured within the persistence
time.

For more information on persistence, refer to

●

Chapter 3.3.3.1, "Using Persistence", on page 30

25User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Persistence Spectrum Result Display

Evaluating the data

After it has collected the data of one frame, the R&S ESR copies all the spectrums
included in that frame into the display. If all spectrums were identical, the resulting per­sistence spectrum would look like a line trace, but in color. However, in reality none of
the spectrums looks alike, therefore the fact that many spectrums are on top of each
other leads to a diagram that covers a two dimensional area on the screen instead of
just a line.

There will be pixels that the spectrum runs through more often than others, whose
spectral density is higher than elsewhere. To represent this fact, the R&S ESR copies
all spectrums into a virtual table whose dimensions correspond to the resolution of the
display with each cell representing one pixel. The horizontal represents the frequency,
the vertical axis the amplitude. In the case of the R&S ESR with a resolution of
600x801 pixels, this means that the table would have 480.600 cells. With a full span of
40 MHz and the default display range of 100 dB, one cell would cover about 50 kHz
and 0.16 dB.

After the R&S ESR has performed the first FFT and has transferred the corresponding
spectrum, the table would, for example, look like this:

Figure 3-5: Virtual table and diagram containing the results after one FFT

Since there is only one spectrum and every number in the table represents the number
of hits in that cell, each column, at this point, has to contain exactly one value. The
sum of each column may not exceed the value '1', as, currently, there is only one spec­trum. Additionaly, every column must include a number (one for each frequency/ level
combination). The display of the trace after this step would look like a line trace.

But as the frame consists of more than one spectrum, the R&S ESR accumulates all
spectrums it has captured. Let's assume a frame consists of 10 spectrums. After a sin­gle sweep, the table would, for example, look like this:

26User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Persistence Spectrum Result Display

Figure 3-6: Virtual table and diagram containing the results after one frame (n FFTs)

As you can see many cells contain a value greater than '1'. A number greater than one
expresses an overlap of several spectrums on this pixel. As the assumed frame con­sists of 10 spectrums, the sum of values in each column must equal '10'.

Calculating percentages

Now that all values have been transferred into the table, the R&S ESR converts the
absolute numbers into relative values or percentages. The percentages are the basis
of the final histogram that the R&S ESR shows on the display.

The percentage of one cell is simply the ratio of the number of hits in that cell over the
number of accumulated spectrums.

Example:

The percentage of, e.g., the value in the highlighted cells would be 0.2 or 20% (2 hits
and a total number of 10 spectrums, n=(2/10)*100%). After the R&S ESR has calcula­ted all percentages, the table would look like this:

Figure 3-7: Virtual table containing the percentages of the results after one frame

The values in the table are the percentages, so that the sum of each column is always
100%.

With a long observation time, the percentage becomes a statistical value that shows
the probability of the occurence of a particular frequency/ level combination.

Coloring

To visualize the percentages in the persistence spectrum, the R&S ESR uses different
colors for different values. That means the final step of creating the persistence spec-

27User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Persistence Spectrum Result Display

trum is the mapping of colors to every pixel with each color representing a particular
percentage or probability that is shown in the color map in the title bar of the result dis­play.

The color the R&S ESR assigns to the percentage depends on:

●

the color scheme you have selected

●

the color mapping settings you have set

In the default configuration (color scheme "Hot"), the R&S ESR shows low percentages
with 'cold' colors (blue, green etc.) and high percentages in 'warm' colors (red, yellow
etc.).

Applying colors to 3-7 would result in a picture like this:

Figure 3-8: Virtual table and result display containing the colored results

As you can see in

3-8, the most frequent spectral parts appear in red, while all others

appear in colder colors.

Up until now, the process was for one frame only and no active persistence and no
maxhold function. If you activate those, the process of drawing the persistence spec­trum gets more complex.

For more information, see

●

Chapter 3.3.3.1, "Using Persistence", on page 30

●

Chapter 3.3.3.2, "Activating Maxhold", on page 31

28User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

3.3.1 Screen Layout of the Persistence Spectrum

Measurements and Result Displays

The Persistence Spectrum Result Display

1 = Screen number
2 = Trace information for the realtime spectrum trace (trace mode and detector)
3 = Color map
4 = Trace window (or diagram area)
5 = Marker
6 = Marker information
7 = Realtime spectrum trace (white line)
8 = Persistence spectrum (colored trace)
9 = maxhold trace (weak color intensity)

The persistence spectrum has three 'layers':

●

the realtime spectrum trace. This trace is always white so that you can recognize it
inside the histogram. It is updated continuously.

●

the histogram. The histogram is the main feature of the result display. The colors
the histogram show the number of hits of level/frequency combinations. The num­ber of FFTs each pixel in the measurement diagram contains depends on the gran­ularity. The histogram is multicolored.

●

the maxhold trace. The maxhold trace is a transparent trace in the background of
the histogram that shows the maximum percentages that have been measured up
to the present. The maxhold trace is in the 'background' of the result display with a
lower intensity than the histogram. By default, the maxhold trace is inactive, i.e. it
has an intensity of 0. You can, however, adjust the color intensity to the point where
the maxhold trace has the same intensity as the regular histogram. The maxhold
trace is also multicolored.

3.3.2 Applications of the Persistence Spectrum

The persistence spectrum is useful for any measurement task that requires information
about the statistical frequency of a spectral event. When you know the relative fre­quency of an event, you can also deduce the probability with which that event will
occur.

A typical application for the persistence spectrum is the detection of weak or hidden
signals that occur infrequent. Weak signals may be hidden in the noise or occur in
between strong pulses and therefore cannot be detected with standard result displays.

29User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Persistence Spectrum Result Display

The persistence spectrum on the other hand shows those signals because they have a
different probability than other signals. With a different probability, the color mapping
also is different and it is easy for you to identify those signals.

You can also identify spurs more easily with the persistence spectrum because their
probability differs. With an active persistence, you can also see them or their shadows
for a longer time on the result display which makes it easier not to miss them.

This fact also makes it easier to monitor the spectrum and, e.g. observe interfering sig­nals in a frequency band reserved for a particular application. When monitoring the
spectrum with the persistence spectrum, you can not only see interfering signals but
also observe the frequency with which they occur and therefore derive from the density
if it was a one time occurence only or if the interfering signal is transmitted regularily.

There are however limits to the information the persistence spectrum is capable to pro­vide. If you need to know, for example, how long a particular frequency/level combina­tion is present, you have to use another result display, because the persistence spec­trum doesn't tell whether there is a single very long pulse (e.g. one 5 ms pulse) or sev­eral short ones (e.g. ten 50 µs pulses).

3.3.3 Configuring the Persistence Spectrum

You can customize the persistence spectrum in several ways. You can change the col­ors with which the densities are visualized, you can change the persistence of the data
and change the style of the displayed results.

TRACe<n>[:DATA] on page 115

3.3.3.1 Using Persistence

Persistence is a term to describe the time period shadows of past histogram traces
remain visible in the display before fading away.

The term persistence has its origins in cathode ray tube devices (CRTs). It describes
the time period one point on the display stays illuminated after it has been lit by the
cathode ray. The higher the persistence, the longer you could observe the illuminated
point on the display.

In the persistence spectrum, the persistence results from the moving 'density' (like a
moving average) over a certain number of traces. The number of traces that are con­sidered for calculating the density depend on the persistence length that you can
define with the "Persistence" softkey. The longer the persistence, the more traces are
part of the calculation and the deeper the history of displayed information gets. A spec­tral event that has occured a single time is visible for up to 8 seconds. That means that
colors will change as densities get smaller at coordinates with signal parts that are not
constantly there, but still have the same intensity as the original signal. The rate of the
color change is high with a low persistence and small with a high persistence.

Note that a signal with constant frequency and level characteristics does not show the
effects of persistence on the trace. As soon as the power or frequency of a signal
change slightly, however, the effect of persistence gets visible through color changes or
changes in the shape of the trace.

30User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

3.3.3.2 Activating Maxhold

Measurements and Result Displays

The Persistence Spectrum Result Display

You can turn off persistence if you set it to 0 seconds.

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:PERSistence:DURation

on page 79

Defining the granularity

The amount of data that the R&S ESR uses to draw a single frame in the persistence
spectrum is variable. By default it uses the data that was captured in a 100 ms in the
moving 'density'. With the "Persistence Granularity" softkey, you can set the amount of
data that the R&S ESR uses to build the persistence spectrum by increasing or
decreasing the persistence granularity.

DISPlay:WINDow[:SUBWindow]:TRACe:PERSistence:GRANularity

on page 79

The maxhold function remembers and shows the maximum densities that have been
measured at each point in the diagram. The maxhold trace is visible as soon as you
increase the color intensity and will remain visible until you reset the maxhold, turn it off
or preset the R&S ESR.

Changing the color intensity

In its default state, the R&S ESR does not display the maxhold trace. You can turn it on
by increasing the color intensity. With the "Maxhold Intensity" softkey, you can regulate
the brightness of the trace up to the point where it is as intense as the current trace.

Note that the color intensity of the maxhold trace is lower than that of the trace itself.
The color distribution, however, is the same for both traces.

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:MAXHold[:INTensity]

on page 78

Resetting the maxhold trace

You can reset the maxhold trace with the "Maxhold Reset" softkey. The R&S ESR then
starts to build the maxhold trace again.

DISPlay:WINDow[:SUBWindow]:TRACe:MAXHold:RESet on page 78

Turning off the maxhold trace

To turn off the maxhold trace, set the maxhold intensity to zero.

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:MAXHold[:INTensity]

on page 78

3.3.3.3 Selecting the Style of the Trace

The R&S ESR offers two styles that you can apply to the persistence spectrum, vecto­rial or dotted display. Select the style of the trace with the "Style (Vec Dots)" softkey.

31User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurements and Result Displays

The Persistence Spectrum Result Display

The vectorial display of the measurement results is an interpolation of all the individual
points and therefore an interpolation of densities. The result is a persistence spectrum
that contains no gaps between coordinates. Each point of the histogram is connected
to the neighboring ones.

The dotted display on the other hand plots and colors only those coordinates where
data has been actually measured. The result is a histogram made up out of literally
thousands of individual points.

Figure 3-9: Dotted trace style vs Vector trace style

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:SYMBol on page 80

3.3.3.4 Customizing the Color Mapping

For more information, see Chapter 3.2.3.3, "Customizing the Color Mapping",
on page 20

32User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4 Measurement Basics

4.1 Data Acquisition and Processing in a Realtime Ana-

Measurement Basics

Data Acquisition and Processing in a Realtime Analyzer

● Data Acquisition and Processing in a Realtime Analyzer....................................... 33

● Configuring Realtime Measurements......................................................................35

● Triggering Measurements....................................................................................... 38

● Using Markers.........................................................................................................44

● Detector Overview...................................................................................................46

● ASCII File Export Format........................................................................................ 47

lyzer

This chapter shows the way the R&S ESR acquires and processes the data compared
to a conventional spectrum analyzer.

A conventional spectrum analyzer typically loses information after it has captured the
signal ('blind time'). This is because the LO has to return to the start frequency after a
sweep of the selected frequency range (LO flyback). Blind time therefore occurs after
the data capture and signal processing and before the next data capture can begin.

Figure 4-1: Conventional spectrum analyzer measurement principle

= Note that the time axis is not true to scale. Blind time is a lot shorter in reality.
1 = Signals are captured by the sweep.
2 = Signal is missed by the sweep because of LO flyback (blind time).

Because of a number of reasons, a realtime analyzer does not lose any information.

First, there is no LO flyback because the LO of the realtime analyzer is set to a fixed
frequency. Second, it performs overlapping Fast Fourier Transformations (FFT) instead
of sweeping the spectrum or performing one FFT after another. The overlap of FFTs
also ensures that the R&S ESR can process pulses with a length of at least one FFT
with correct levels. Third, the R&S ESR captures data and performs FFTs at the same
time instead of sequentially capturing data and performing FFT.

To get the results, the R&S ESR simultaneously performs several processing stages:

●

Acquiring the data

33User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Data Acquisition and Processing in a Realtime Analyzer

●

Processing the data

●

Displaying the data

Figure 4-2: Block diagram of the R&S ESR

Measurement Basics

Acquiring the data

The data acquisition process is the same as in a conventional spectrum analyzer. First,
the R&S ESR either attenuates the signal that you have applied to the RF input to get
a signal level that the R&S ESR can handle or, if you have a weak signal, preamplifies
the signal and then down-converts the RF signal to an intermediary frequency (IF),
usually in several stages.

After the down-conversion, the R&S ESR samples the signal into a digital data stream
that is the basis for the Fast Fourier Transformation (FFT). The sampling rate the
R&S ESR uses for sampling is variable, but depends on the span you have set. The
maximum span is 40 MHz.

Figure 4-3: Continuous data stream

At the same time, the A/D data is captured in the I/Q memory.

Processing the data

The R&S ESR then splits the data stream stored in the I/Q memory into data blocks
whose length is 1024 samples each to prepare it for the FFT.

Then the R&S ESR performs the FFT on all data blocks it has acquired. The FFT pro­cessing rate of the R&S ESR is 250.000 FFTs per second.

The distinctive feature of a realtime analyzer is that it uses a particular amount of data
more than once to get the measurement results. It takes the first data block of 1024
samples and performs the FFT on it. The second and all subsequent data blocks, how­ever, do not start at the next sample (in the case of the second block, the 1025th), but

34User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurement Basics

Configuring Realtime Measurements

at an earlier one. In fact, all data, except the first few samples, is processed more than
once and overlapped to get the results.

At full span (40 MHz) this overlap of the FFTs is 80%. That means the second data
block the R&S ESR performs the FFT on covers the last 80% of the data of the first
FFT with onl 20% new data. The third data block still covers 60% of the first data block
and 80% of the second data block and so on.

Figure 4-4: Overlapping FFTs

The percentage of the overlap depends on the sampling rate and therefore on the span
that you have set. With a span of 40 MHz, the overlap is 80%. If you reduce the span,
the FFT machine tries to keep the FFT processing rate and increases teh overlap
accordingly. In that way, the overlap can increase up to a value of 1023 overlapping
samples out of 1024 samples.

After the FFT is done and the spectrums have been calculated, the result is a stream
of spectrums without information loss. For every spectrum, the R&S ESR gets 1024
measurement points. However, because of data reduction and the filter slope of the
DDC, it only uses 801 points to get the displayed results.

Displaying the data

From here on, the data processing depends on the result display that you have
selected. The details for every available result displays are discussed below.

4.2 Configuring Realtime Measurements

Three distinctive parameters for realtime analysis are the span, the sweep time and the
resolution bandwidth.

The span and resolution bandwidth are directly coupled to each other.

4.2.1 Configuring the Sweep

The R&S ESR provides various functions to configure the way it performs measure­ments.

35User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurement Basics

Configuring Realtime Measurements

In its default state, the R&S ESR continuously measures the signal that you have
applied in the way described in Chapter 4.1, "Data Acquisition and Processing in a

Realtime Analyzer", on page 33 and according to the trigger settings.

You can interrupt the continuous measurement with the "Continuous Sweep Stop" soft­key if you want to examine a signal further. To resume the continuous measurement,
use the "Continuous Sweep Start" softkey.

In single sweep mode, on the other hand, the R&S ESR performs a finite number of
sweeps. The number of sweeps that the R&S ESR performs depends on the sweep
count, defined with the "Sweep Count" softkey in the sweep menu. If you set the
sweep count to 0 or 1, the R&S ESR performs one sweep. One sweep corresponds to
the sweep time. You can activate the single sweep mode with the "Single Sweep" soft­key.

After the single sweep has ended, you can repeat the single sweep measurement with
either the "Single Sweep" softkey or the "Continue Single Sweep" softkey. The differ­ence is that when continuing the single sweep, the R&S ESR does not delete the trace
data of the last measurement for averaging purposes. When you instead repeat the
single sweep with the "Single Sweep" softkey, the R&S ESR completely rebuilds the
trace from new data.

INITiate<n>:CONTinuous on page 100

INITiate<n>:CONMeas on page 99

[SENSe:]SWEep:COUNt on page 101

CALCulate<n>:SGRam:FRAMe:COUNt on page 83

4.2.2 Setting the Sweep Time

In the frequency domain of the realtime analyzer, the sweep time defines the number
of FFTs that the R&S ESR combines in one frame or single sweep.

In realtime mode, the R&S ESR has a sweep time range from 52 µs to 1 s, with 1 s
processing 250.000 FFTs. The step size of the sweep time is 4 µs.

The advantage of a small sweep time therefore is a very detailed evaluation and dis­play of the signal that you are measuring. On the other hand, a high sweep time dis­plays more time in a single frame. That means that you can observe a longer time
span in the spectrogram the higher the sweep time is.

Manual setting of the sweep time

You can set the sweep time as you need with the "Sweeptime Manual". This softkey is
available in the span, bandwidth and sweep menus.

[SENSe:]SWEep:TIME on page 101

36User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4.2.3 Setting the Span

Measurement Basics

Configuring Realtime Measurements

Automatic setting of the sweep time

If you activate the automatic sweep time with the "Sweeptime Auto" softkey, the
R&S ESR sets the sweep time to 30 ms. The "Sweeptime Auto" softkey is available in
the bandwidth and sweep menus.

[SENSe:]SWEep:TIME:AUTO on page 101

The span (or realtime bandwidth) defines the frequency range that the R&S ESR
shows in result displays with a horizontal axis showing the frequency.

The span you should use depends on the signal that you are measuring. It should,
however, be about twice as large as the bandwidth of the signal.

In realtime mode, the R&S ESR has a minimum span of 100 Hz and a maximum span
of 40 MHz.

You can set the span in several ways.

Setting the span

You can set the directly with the "Span Manual" softkey or the [SPAN] key.

If you change the span in this way, the center frequency always corresponds to the
center of the span and remains the same, no matter how you change the span.

[SENSe:]FREQuency:SPAN on page 90

Defining a start and stop frequency

Another way to set the span is to define a start and stop frequency with the "Start" and
"Stop" softkeys in the frequency menu.

Changing the start and stop frequencies invalidates the center frequency and span set­tings that you have previously made.

Note that if you enter a start and stop frequency that would result in a span larger than
40 MHz, the R&S ESR always narrows the span down to 40 MHz.

Example:

If you first enter a start frequency of 100 MHz and then a stop frequency of 150 MHz,
the R&S ESR adjusts the start frequency to 110 MHz.

If you first enter a stop frequency of 150 MHz and then a start frequency of 100 MHz,
the R&S ESR adjusts the stop frequency to 140 MHz.

[SENSe:]FREQuency:STARt on page 90

[SENSe:]FREQuency:STOP on page 90

Restoring the full span

You can always restore the full span (40 MHz) with the "Full Span" softkey.

37User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4.2.4 Setting the Resolution Bandwidth

Measurement Basics

Triggering Measurements

[SENSe:]FREQuency:SPAN:FULL on page 90

The aspect of the signal as appears on the display of the R&S ESR depends on the
resolution filter bandwidth that you have set. The resolution bandwidth determines the
frequency resolution of a measurements.

The resolution bandwidth is directly coupled to the span of the R&S ESR. If you
increase or decrease the span, the resolution bandwidth also goes up or down.

If neccessary, you can apply a fix coupling ratio between the resolution bandwith and
the span in the "Coupling Ratio" menu. The R&S ESR provides several coupling ratios
from which you can select.

A small resolution bandwidth has several advantages. The smaller the resolution band­width, the better you can observe signals whose frequencies are close together and
the less noise is displayed. However, a small resolution bandwidth also leads to a
slower measurement as it takes the filter more time to settle. That means that if you
increase or decrease the resolution bandwidth, the R&S ESR adjusts the sweep time
accordingly.

The R&S ESR has resolution bandwidths from 500 mHz to 200 kHz in 1-2-5 steps
(1 Hz - 2 Hz - 5 Hz - 10 Hz etc.).

You can set the resolution bandwidth with the "Manual Res BW" softkey.

In addition, you can select several 6 dB resolution bandwidths. You can turn the func­tionality on with the "Res BW 6 dB (On Off)" softkey and then select the available
bandwidths with the "Res BW Manual" softkey. For more information on these EMI
bandwidths see the manual of the R&S ESR.

[SENSe:]BANDwidth|BWIDth[:RESolution] on page 91

[SENSe:]BANDwidth|BWIDth[:RESolution]:AUTO on page 91

4.3 Triggering Measurements

To respond to certain events and trigger a measurement when that event happens, the
R&S ESR offers several trigger functions. You can access these via the [TRIG] key and
the corresponding softkey menu.

This chapter describes trigger functions available for the measurements in realtime
spectrum analyzer mode.

4.3.1 Working with the Frequency Mask Trigger

The Frequency Mask Trigger (FMT) is a trigger designed to trigger measurements if
the signal violates certain conditions with respect to a frequency mask that you can
define prior to the measurement.

38User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurement Basics

Triggering Measurements

To create and edit a frequency mask, you can access the corresponding dialog box via
the "Frequency Mask" softkey in the trigger menu.

Opening the dialog box also opens a softkey submenu that contains various functional­ity to work with frequency masks.

1 = Name and description of the frequency mask
2 = Mask point table: table containing all mask points
3 = Preview pane
4 = Frequency mask preview: the area the frequency mask currently covers is red
5 = Frequency mask data points: define the shape of the frequency mask
6 = Preview of the current measurement trace; type and shape depend on currently selected measurement
7 = Insert button: insert a new data points
8 = Shift X button: shifts the complete frequency mask horizontally
9 = Delete button: deletes an existing data points
10 = Shift Y button: shifts the complete frequency mask vertically
11 = Y-Axis Rel/Abs button: switches between relative (dB) and absolute (dBm) amplitude values
12 = Adapt Mask button: creates a frequency mask automatically
13 = Trigger Condition menu: sets the trigger condition
14 = Activate Line buttons: select the upper and lower frequency mask; check marks next to the buttons acti-

vate and deactivate a line

4.3.1.1 Creating a Frequency Mask

Upon opening the "Edit Frequency Mask" dialog box, the R&S ESR already provides a
basic structure of an upper frequency mask in the live preview window.

It is also possible to create a new mask by pressing the "New Mask" softkey. The "New
Mask" softkey resets the current shape of the mask to its default state.

39User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurement Basics

Triggering Measurements

Labelling a frequency mask

Assign a name to the frequency mask in the "Name" field. Activate the input in the
"Name" field either by touching it or via the "Edit Name" softkey. This is also the save
name of the frequency mask.

In addition to naming the mask, you can also comment on the frequency mask you are
working on in the "Comment" field. Again, activate the input either by touching it or with
the "Edit Comment" softkey.

Remote command:

CALCulate<n>:MASK:COMMent on page 106
CALCulate<n>:MASK:NAME on page 109

Defining the frequency mask span

Define the span of the frequency mask.
The span defines the range that the frequency mask covers on the frequency axis.
Remote command:

CALCulate<n>:MASK:SPAN on page 109

Working with upper and lower lines

A frequency mask may have an upper and a lower threshold, with the signal in
between. The checkboxes next to the "Upper Line" and "Lower Line" buttons activate
or deactivate the corresponding line. Note that it is not possible to deactivate both
lines.

You can select the line you want to edit with the "Upper Line" / "Lower Line" buttons or
by touching the corresponding area in the preview to apply any changes. The buttons
turn blue if a line is selected and the R&S ESR shows the data points in the area cov­ered by the mask in the preview pane.

Remote command:

CALCulate<n>:MASK:LOWer[:STATe] on page 108
CALCulate<n>:MASK:UPPer[:STATe] on page 110

Setting the trigger condition

To make the trigger work, you need to set a trigger condition with the "Trigger Condi­tion" button. The R&S ESR supports four conditions.

"Entering"

"Leaving"

Remote command:

TRIGger<n>[:SEQuence]:MASK:CONDition on page 111

Activates the trigger as soon as the signal enters the frequency mask.
To arm the trigger, the signal initially has to be outside the frequency
mask.

Activates the trigger as soon as the signal leaves the frequency
mask.
To arm the trigger, the signal initially has to be inside the frequency
mask.

40User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4.3.1.2 Editing Mask Points

Measurement Basics

Triggering Measurements

You can adjust the frequency mask any way you want by adding, removing and reposi­tioning frequency mask data points.

Data points define the shape of the frequency mask. In the preview pane, the
R&S ESR visualizes data points as blue circles. In addition, all data point positions are
listed in the data point table. The number of data points is limited to 801.

Data points are defined by two values. The first value defines the position of the data
point on the horizontal (frequency) axis. Frequency information is relative to the center
frequency.

Note that in realtime mode, the span depends on the realtime bandwidth. That also
means that the distance of a data point to the center frequency can never exceed
20 MHz as the maximum realtime bandwidth is 40 MHz.

The second value defines the position of the data point on the vertical (level) axis. By
default, level information is relative to the reference level. You can, however, turn the
level axis to absolute scaling with the "Y-Axis Abs/Rel" button. This also changes the
unit of the vertical axis (dB for relative data points, dBm for absolute data points).

Adding data points

To add a new data point, press the "Insert" button or the "Insert Value Above" softkey.
The R&S ESR always adds the data point to the left (or in case of the table, above) of
the currently selected data point. The currently selected data point is highlighted gray
in the table. If no data point was selected previously, the buttons add a new point next
to the very first one.

Deleting data points

The "Delete" button or the "Delete Value" softkey remove a data point from the mask.
The R&S ESR deletes the currently selected data point. If no data point is selected, it
deletes the first one. The "Delete" button is inactive in that case.

Positioning data points

There are two ways to move a single data point.
In the preview pane, you can drag around the data points on the touchscreen or with a

mouse and position it roughly in the place you want it to be. A more exact method is to
edit the data point table itself end enter the frequencies and levels as you need.

Remote command:

CALCulate<n>:MASK:LOWer[:DATA] on page 108
CALCulate<n>:MASK:UPPer[:DATA] on page 110

Shifting mask points as a whole

With the "Shift X" and "Shift Y" buttons you are able to move all mask points of a fre­quency mask as one. The "Shift X" button moves the mask point set horizontally, while
the "Shift Y" button moves them vertically. This is an easy method to move mask points
if the relative position of mask points to each other is alright already without adjusting
each one by itself.

41User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4.3.1.3 Managing Frequency Masks

Measurement Basics

Triggering Measurements

Remote command:

CALCulate<n>:MASK:LOWer:SHIFt:X on page 107
CALCulate<n>:MASK:LOWer:SHIFt:Y on page 107
CALCulate<n>:MASK:UPPer:SHIFt:X on page 109
CALCulate<n>:MASK:UPPer:SHIFt:Y on page 110

Automatic alignment of the frequency mask

Instead of defining the position of every data point by hand, the R&S ESR is able to
shape the frequency mask according to the shape of the current signal. On pressing
the "Auto Set Mask" button, the R&S ESR forms the frequency mask around the cur­rent spectrum.

Note the the automatic alignment of the frequency mask works only for the upper fre­quency mask.

Remote command:

CALCulate<n>:MASK:UPPer[:DATA] on page 110

To be able to reuse or edit a frequency mask that you have defined later, you can save
and restore particular frequency mask configurations.

The R&S ESR stores files that contain such configurations on its internal hard disk.

Save Mask

The "Save" softkey opens a dialog box to save the current frequency mask configura­tion in a file.

If you do not name the file in the dialog box, the R&S ESR names the file like the name
of the frequency mask itself.

Load Mask

The "Load" softkey opens a dialog box to restore a frequency mask.
The dialog box contains all frequency masks already on the hard disk of the R&S ESR.

Select the mask you need and confirm the selection with the "Load" button.
Remote command:

Path selection:

CALCulate<n>:MASK:CDIRectory on page 106

Load mask:

CALCulate<n>:MASK:NAME on page 109

Delete Mask

The Delete softkey opens a dialog box to delete a previously saved frequency mask.
The "Delete" button deletes the file. Note that you have to confirm the deletion process.
Remote command:

CALCulate<n>:MASK:DELete on page 107

42User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4.3.2 Using the Time Domain Trigger

4.3.3 Using Other Triggers

Measurement Basics

Triggering Measurements

The time domain trigger is a trigger designed to trigger measurements if the signal
exceeds a particular power level. Activate and define a power level for the time domain
trigger by pressing the "Time Domain Trigger" softkey in the trigger menu.

The time domain trigger is available for measurements in the time domain. You can
turn it off by selecting the free run mode.

TRIGger<n>[:SEQuence]:TDTRigger:LEVel on page 104

Besides the frequency mask trigger and the time domain trigger, the R&S ESR fea­tures various other trigger modes.

Available trigger sources

●

External
Activate and define a power level for the external trigger by pressing the "Time
Domain Trigger" softkey in the trigger menu.

●

Free Run
Turns off all trigger sources.

For more information see

●

"Free Run" on page 63

●

"External" on page 63

4.3.4 Using Pre- and Posttrigger

When using a trigger, you can set a "Pretrigger" and a "Posttrigger" period with the cor­responding softkeys. Each can last up to three seconds. Both combined, however can­not be longer than four seconds.

Example:

If the pretrigger has a length of 3 seconds, the posttrigger can last a maximum of
1 second.

4.3.5 Rearming the Trigger and Stopping on Trigger

Auto Rearm

By default, a trigger event causes the R&S ESR to start a measurement and to imme­diately rearm the trigger. In that case, measurements are continuously triggered and
measurement results may become obsolete in a very short time. The pre- and posttrig­ger periods are completely displayed.

43User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4.4 Using Markers

Measurement Basics

Using Markers

Stop on Trigger

However, you may be interested in the results after the first trigger event only. To do
so, you can activate the "Stop on Trigger" feature. If active, this feature does not rearm
the trigger after the first trigger event has occured and stop the measurement after one
sweep. The measurement results will remain on the display. If a posttrigger is active,
the R&S ESR includes this period in the result display. The pretrigger period may not
be displayed.

You can return to the default state (continuous triggering) with the "Auto Rearm" soft­key.

TRIGger:MODE on page 102

All of the result displays available in realtime spectrum mode support marker function­ality.

Markers are a means to mark points of interest in the diagram, to read out measure­ment results or to quickly get hold of measurement results that are currently not visible.
In most result displays, you can either use markers or deltamarkers with deltamarkers
always having a relative position to a normal marker.

The marker that you can control is the active marker.

The R&S ESR displays all necessary information about the active marker inside the
diagram area in the marker information field. The information that is displayed depends
on the result display.

This chapter describes distinctive features of the marker functionality for the result dis­plays in realtime spectrum mode.

For general information about markers and the contents of the marker, marker to and
marker function softkey menus, see

●

Chapter 6.2, "Using Markers", on page 68

4.4.1 Markers in a Spectrogram

Upon pressing the [MKR] key, the R&S ESR opens an input field to define the position
of the first marker.

Figure 4-5: Marker input field

Every marker in the spectrogram has two coordinates. If the realtime spectrum is
active at the same time the spectrogram is active, the realtime spectrum markers also
have two coordinates.

The first coordinate defines the frequency of the marker.

44User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurement Basics

Using Markers

The second coordinate defines the position of the marker in time. The unit depends on
whether the time stamp is active or not. If it is inactive, you have to define a particular
frame number relative to the current frame. If not, you have to set the distance to the
current frame in seconds. The R&S ESR then evaluates the corresponding frame num­ber automatically. The time value for normal markers is always negative, because the
temporal marker position is always relative to the current frame. Deltamarkers can also
have positive values, if you set them on a frame recorded after the frame the marker is
on.

The recording date and time of the frame (displayed in the spectrogram footer) is
adjusted accordingly.

The available history depth defines the maximum time range.

As soon as the first marker is active, the R&S ESR also shows the marker information
in the diagram area

Figure 4-6: Marker information

1 = Marker (Mx) and deltamarker (Dx) information including the trace number [x] the marker is on
2 = Position of the marker in time (relative to the marker in case of the deltamarker)
3 = Frequency position of the marker (relative to the marker in case of the deltamarker)
4 = Level of the marker position (relative to the marker in case of the deltamarker)

If necessary (for example to get a better view of the diagram contents), you can turn
the marker information on or off with the "Marker info (On Off)" softkey.

All results concerning normal markers are absolute values (frequency, level and time
information) while results of the deltamarker are relative to the normal marker.

Markers and deltamarkers in the realtime spectrum result display are always coupled
to the spectrogram and vice versa, no matter if you are viewing both at the same time
or not.

In the realtime spectrum, markers have the form of a triangle ( ). As long as the spec­trogram is running, markers are not available in the realtime spectrum. If you stop the
spectrogram by switching to single sweep mode or by interrupting the continuous
sweep mode, markers become available for the realtime spectrum. You can then select
a particular frame in the spectrogram to recall the corresponding realtime spectrum,
and place the markers there. The markers of spectrogram and realtime spectrum are
always synchronized in time.

Markers in the spectrogram look like diamonds ( ). You can set them on any frame
stored in the spectrogram history and on any frequency you want. No matter the sweep
mode, they will be visible and stay where you have put them. If you place them too far
in the past or too far from each other vertically or horizontally, however, it may be that
one or more markers are no longer visible in the result display. To see the marker in
that case, you have to select it first.

For more information, see

●

Chapter 3.2.3.1, "Working with the Spectrogram History", on page 15

45User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

4.4.2 Markers in the Persistence Spectrum

Measurement Basics

Detector Overview

Setting a marker on a trigger event

In the spectrogram, you can set the marker directly on the most recent trigger event
with the "Marker to Trigger" softkey available in the marker to menu. The functionality
is available only if there was a trigger event already.

For a list of remote commands to control markers and deltamarkers see

●

Chapter 7.4.2.3, "Positioning Markers in the Spectrogram", on page 131

●

Chapter 7.4.2.5, "Positioning Delta Markers in the Spectrogram", on page 140

If you press the [MKR] key in the persistence spectrum, the R&S ESR activates a
marker and opens a dialog box to define the position of the marker. In the persistence
spectrum the marker looks like cross hairs with the center focusing on the pixel that
you want to analyze.

A Marker in the persistence spectrum has two coordinates. The first coordinate defines
the frequency position of the marker. The second coordinate defines the position on
the amplitude axis.

In addition to those two values, the marker provides the number of times the pixel it is
on has been hit by the signal. The result is the statistical frequency in %.

As soon as the first marker is active, the R&S ESR also shows the marker information
in the diagram area.

All results concerning normal markers are absolute values (frequency and level) while
results of the frequency and amplitude information of a deltamarker are relative to the
normal marker. The statistical frequency distribution that the marker also shows is
always absolute.

Defining the trace to put the marker on

In the persistence spectrum result display, you can place each marker either on the
persistence trace or the maxhold trace, if it is active. The R&S ESR then returns the
data of the marker position for the corresponding trace. You can select the trace with
the "(Current Maxhold)" softkey.

CALCulate<n>:MARKer<m>:TRACe on page 118

4.5 Detector Overview

The measurement detector for the individual display modes can be selected directly by
the user or set automatically by the R&S ESR. The detector activated for the specific
trace is indicated in the corresponding trace display field by an abbreviation.

For more information on available detectors see the documentation of the base unit.

All detectors work in parallel in the background, which means that the measurement
speed is independent of the detector combination used for different traces.

46User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Measurement Basics

ASCII File Export Format

Number of measured values

During a frequency sweep, the R&S ESR increments the first local oscillator in steps
that are smaller than approximately 1/10 of the bandwidth. This ensures that the oscil­lator step speed is conform to the hardware settling times and does not affect the pre­cision of the measured power.

The number of measured values taken during a sweep is independent of the number of
oscillator steps. It is always selected as a multiple or a fraction of 691 (= default num­ber of trace points displayed on the screen). Choosing less then 691 measured values
(e.g. 125 or 251) will lead to an interpolated measurement curve, choosing more than
691 points (e.g. 1001, 2001 …) will result in several measured values being overlaid at
the same frequency position.

RMS detector and VBW

If the RMS detector is selected, the video bandwidth in the hardware is bypassed.
Thus, duplicate trace averaging with small VBWs and RMS detector no longer occurs.
However, the VBW is still considered when calculating the sweep time. This leads to a
longer sweep time for small VBW values. Thus, you can reduce the VBW value to ach­ieve more stable trace curves even when using an RMS detector. Normally, if the RMS
detector is used the sweep time should be increased to get more stable trace curves.

4.6 ASCII File Export Format

The data of the file header consist of three columns, each separated by a semicolon:
parameter name; numeric value; basic unit. The data section starts with the keyword
"Trace <n>" (<n> = number of stored trace), followed by the measured data in one or
several columns (depending on measurement) which are also separated by a semico­lon.

Exporting a single trace vs exporting all traces

Note that the file containing the trace data has a slightly different structure when you
export all traces compared to exporting a single trace only. The differences are indica­ted in the tables below.

47User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Blue font: Information provided when you export a single trace

Green font: Information provided when you export all traces

Black font: Information provided regardless of the export mode

Header

Type; <instrument_model>; Instrument model
Version;1.00; Firmware version
Date;01. Jan 3000; Date of data set storage
Mode;Receiver; Application
Start;150000.000000;Hz Start frequency of the scan
Stop;100000000.000000;Hz; Stop frequency of the scan
X-Axis;LIN;

Detector;Average; Detector type

X-Unit;Hz;
Y-Unit;dBµV;

Scan Count;1;
Transducer;;;;;;;;

Scale of the x-axis

Unit of the x-axis
Unit of the y-axis

Scan count
Transducer information

Measurement Basics

ASCII File Export Format

Data section (scan ranges)

Scan 1:
Start;150000.000000;Hz; Start frequency of the scan range
Stop;29998500.000000;Hz; Stop frequency of the scan range
Step;4500.000000;Hz; Frequency stepsize applied in the scan range
RBW;9000.000000;Hz; Measurement bandwidth applied in the scan range
Meas Time;0.001000;s; Measurement time in the scan range
Auto Ranging;OFF; State of the auto ranging feature
RF Att;10.000000;dB; Attenuation applied in the scan range

Auto Preamp;OFF;
Preamp;0.000000;dB;

RF Input;1; RF input used in the scan range
Scan 2:
(…)

Data section (traces)

Trace 1:
Trace Mode;CLR/WRITE; Trace mode

Detector;MAX PEAK; Detector type

X-Unit;Hz; Unit of the x-axis
Y-Unit;Hz; Unit of the y-axis

Values;1343; Number of measurement points

150000.000000;3.541122;

154500.000000;5.776306;[...]

Trace 2:
(…)

Preamplifier information for the scan range

String of results

48User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Blue font: Information provided when you export a single trace

Green font: Information provided when you export all traces

Black font: Information provided regardless of the export mode

Header

Type; <instrument_model>; Instrument model
Version;1.00; Firmware version
Date;01. Jan 3000; Date of data set storage
Mode;Analyzer; Application
Center Freq;100000000.000000; Center frequency
Freq Offset;0.000000;Hz; Frequency offset
Span;10000000000.000000;Hz;
X-Axis;LIN; Scale of the x-axis
Start;150000.000000:Hz;
Stop;2500000.000000;Hz;
Ref Level;97.000000;dBµV;
Level Offset;0.000000;Hz;
Ref Position;100.000000;%; Reference position
Y-Axis;LOG; Scale of the y-axis
Level Range;100.000000;dB; Range of the y-axis
Rf Att;10.000000;dB; RF attenuation
RBW;3000000.000000;Hz; Resolution bandwidth
VBW;300000.000000;Hz; Video bandwidth
SWT;0.002000;s; Sweep time

Trace mode;CLR/WRITE; Trace mode
Detector;AUTOPEAK; Detector type

X-Unit;Hz; Unit of the x-axis
Y-Unit;Hz; Unit of the y-axis
Preamplifier;OFF; State of the preamplifier
Transducer;OFF; Transducer information

Sweep Count;0; Sweep / average count

Frequency span

Start frequency
Stop frequency
Reference level
Reference level offset

Measurement Basics

ASCII File Export Format

Data section (traces)

Trace 1:

Trace Mode;CLR/WRITE; Trace mode
Detector;MAX PEAK; Detector type

X-Unit;Hz; Unit of the x-axis
Y-Unit;Hz; Unit of the y-axis
Preamplifier;OFF; State of the preamplifier
Transducer;OFF; Transducer information

Values;691; Number of measurement points

150000.000000;3.541122;

154500.000000;5.776306;[...]

Trace 2:
(…)

String of results

49User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

5 Configuration

Configuration

Result Display Selection

Realtime measurements require a special operating mode on the R&S ESR, which you
activate using the [MODE] key on the front panel.

When you activate a measurement channel in realtime mode, a measurement for the
input signal is started automatically with the default configuration. The "Measurement"
menu is displayed and provides access to the most important configuration functions.

The application provides two main ways to configure a measurement: softkey menus
and dialog boxes.

Softkey menus are located on the right side of the display. They open when you press
one of the keys on the R&S ESR front panel or as a submenu when you press one of
the softkeys.

Dialog boxes usually open when you press a particular softkey.

Note that for easy access, some functions may be available in more than one softkey
menu or dialog box.

5.1 Result Display Selection

For more information on the result displays available for realtime measurements see

Chapter 3, "Measurements and Result Displays", on page 10.

Persistence Spectrum

Starts the Persistence Spectrum result display.

Real-Time Spectrum

Starts the Realtime Spectrum result display.

Spectrogram

Starts the Spectrogram result display.

Display Config

Opens a dialog box to configure the screen layout.
For more information see Chapter 3, "Measurements and Result Displays",

on page 10.
Remote command:

CALCulate<n>:FEED on page 77

Replay Zoom (On Off)

Turns the spectrogram zoom on and off.
For more information see Chapter 3.2.3.2, "Zooming into the Spectrogram",

on page 17.

50User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

5.2 Result Display Configuration

Configuration

Result Display Configuration

Remote command:
Turn zoom on and off:

DISPlay:WINDow[:SUBWindow]:ZOOM:STATe on page 78

Define the zoom area:

DISPlay:WINDow[:SUBWindow]:ZOOM:AREA on page 77

Each result display available with the realtime application features some settings that
have an effect on that result display only. The following paragraphs give a short over­view of the functions available for the result displays of the realtime application.

For a more comprehensive description see Chapter 3.2.3, "Configuring the Spectro-

gram", on page 15 and Chapter 3.3.3, "Configuring the Persistence Spectrum",

on page 30.

● Persistence Spectrum.............................................................................................51

● Spectrogram............................................................................................................52

5.2.1 Persistence Spectrum

Color Mapping...............................................................................................................51

Persistence................................................................................................................... 51

Maxhold Intensity.......................................................................................................... 52

Maxhold Reset.............................................................................................................. 52

Style.............................................................................................................................. 52

Color Mapping

Opens a dialog box to configure the persistence spectrum color map.
For more information see Chapter 3.2.3.3, "Customizing the Color Mapping",

on page 20.
Remote command:

See Chapter 7.2.2.2, "Working with the Color Map", on page 80.

Persistence

Defines the persistence of the displayed data.
For more information see Chapter 3.3.3.1, "Using Persistence", on page 30.
Remote command:

Turn persistence on and off:

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:PERSistence[:STATe]

on page 80
Defin the persistence:

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:PERSistence:DURation

on page 79

51User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Result Display Configuration

Maxhold Intensity

Defines the intensity of the maxhold trace.
For more information see Chapter 3.3.3.2, "Activating Maxhold", on page 31.
Remote command:

Turn the maxhold trace on and off:

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe:MAXHold:[:STATe]

on page 79
Define the intensity of the maxhold trace.

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:MAXHold[:INTensity]

on page 78

Maxhold Reset

Resets the maxhold trace.
For more information see Chapter 3.3.3.2, "Activating Maxhold", on page 31.
Remote command:

DISPlay:WINDow[:SUBWindow]:TRACe:MAXHold:RESet on page 78

Style

Selects the way the persistence spectrum data is displayed.
For more information see Chapter 3.3.3.3, "Selecting the Style of the Trace",

on page 31.
Remote command:

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:SYMBol on page 80

5.2.2 Spectrogram

Color Mapping

Opens a dialog box to configure the spectrogram color map.
For more information see Chapter 3.2.3.3, "Customizing the Color Mapping",

on page 20.
Remote command:

See Chapter 7.2.3.2, "Working with the Color Map", on page 86.

History Depth

Defines the number of spectrogram frames that the R&S ESR saves.
For more information see "Defining the History Depth" on page 15.
Remote command:

CALCulate<n>:SGRam:HDEPth on page 84

Frame Count

Defines the number of frames contained in a single sweep.
For more information see "Defining a Frame Count" on page 15.
Remote command:

CALCulate<n>:SGRam:FRAMe:COUNt on page 83

52User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

5.3 Common Measurement Settings

Configuration

Common Measurement Settings

Clear Spectrogram

Deletes the contents of the spectrogram.
For more information see "Clearing the Spectrogram" on page 16.
Remote command:

CALCulate<n>:SGRam:CLEar[:IMMediate] on page 82

Time Stamp (On Off)

Turns the display of the time information for a particular frame on and off.
For more information see "Using the Time Stamp" on page 16.
Remote command:

CALCulate<n>:SGRam:TSTamp[:STATe] on page 85

Common measurement settings are settings that have an effect on the measurement,
regardless of the result display you are currently using (except where noted).

● Configuring the Sweep............................................................................................53

● Defining the Horizontal Diagram Axis..................................................................... 55

● Defining Level Characteristics.................................................................................57

● Selecting the Measurement Bandwidth...................................................................62

● Triggering Measurements....................................................................................... 63

5.3.1 Configuring the Sweep

The "Sweep" menu contains all functionality to define characteristics of the measure­ment process.

► To access the "Sweep" menu, press the [SWEEP] key on the R&S ESR front

panel.

Continuous Sweep Stop / Start.....................................................................................53

Single Sweep................................................................................................................ 54

Continue Single Sweep.................................................................................................54

Select Frame.................................................................................................................54

Sweeptime Manual (F) / (T) / Auto................................................................................54

Sweep Count.................................................................................................................54

Continue Frame (On Off)...............................................................................................54

Frame Count................................................................................................................. 55

Clear Spectrogram........................................................................................................55

Continuous Sweep Stop / Start

Interrupts, starts or resumes a continuous sweep.
For more information see Chapter 4.2.1, "Configuring the Sweep", on page 35.

53User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

Remote command:

INITiate<n>:CONTinuous on page 100

Single Sweep

Initiates a single sweep.
For more information see Chapter 4.2.1, "Configuring the Sweep", on page 35.
Remote command:

INITiate<n>[:IMMediate] on page 100

Continue Single Sweep

Initiates a single sweep that includes the data of previous measurements in the trace
averaging process.

For more information see Chapter 4.2.1, "Configuring the Sweep", on page 35.
Persistence spectrum only.
Remote command:

INITiate<n>:CONMeas on page 99

Select Frame

Selects a particular frame number of the spectrogram.
For more information see Chapter 3.2.3.1, "Working with the Spectrogram History",

on page 15.
Spectrogram measurements only.
Remote command:

CALCulate<n>:SGRam:FRAMe:SELect on page 83

Sweeptime Manual (F) / (T) / Auto

Defines the sweep time for measurements in the frequency domain "(F)" or time
domain "(T)".

You can define the sweep time manually or automatically.
For more information see Chapter 4.2.2, "Setting the Sweep Time", on page 36.
Remote command:

Manual sweeptime:

[SENSe:]SWEep:TIME on page 101

Automatic sweeptime:

[SENSe:]SWEep:TIME:AUTO on page 101

Sweep Count

Defines the number of sweeps performed during a single sweep sequence.
For more information see Chapter 4.2.1, "Configuring the Sweep", on page 35.
Remote command:

[SENSe:]SWEep:COUNt on page 101

Continue Frame (On Off)

Turns automatic clearing of the spectrogram contents after each sweep on and off.

54User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

For more information see Chapter 3.2.3.1, "Working with the Spectrogram History",
on page 15.

Spectrogram measurements only.
Remote command:

CALCulate<n>:SGRam:CONT on page 82

Frame Count

Defines the number of traces the R&S ESR plots in the spectrogram result display in a
single sweep.

For more information see Chapter 3.2.3.1, "Working with the Spectrogram History",
on page 15.

Spectrogram measurements only.
Remote command:

CALCulate<n>:SGRam:FRAMe:COUNt on page 83

Clear Spectrogram

Clears the contents of the spectrogram.
For more information see Chapter 3.2.3.1, "Working with the Spectrogram History",

on page 15.
Spectrogram measurements only.
Remote command:

CALCulate<n>:SGRam:CLEar[:IMMediate] on page 82

5.3.2 Defining the Horizontal Diagram Axis

The "Span" and "Frequency" menus contain all functions necessary to configure the
horizontal axis.

► To access the "Frequency" menu, press the [FREQ] key on the R&S ESR front

panel.

► To access the "Span" menu, press the [SPAN] key on the R&S ESR front panel.

Center........................................................................................................................... 55

Center Frequency Stepsize...........................................................................................56

Start / Stop.................................................................................................................... 56

Frequency Offset...........................................................................................................56

Span Manual.................................................................................................................56

Sweeptime Manual (F) / (T).......................................................................................... 57

Full Span.......................................................................................................................57

Center

Defines the center or measurement frequency.
The available frequency range depends on the instrument model. For more information

see the data sheet.

55User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

Remote command:

[SENSe:]FREQuency:CENTer on page 88

Center Frequency Stepsize

Defines the step size by which the center frequency is increased or decreased when
the arrow keys are pressed. When you use the rotary knob the center frequency
changes in steps of only 1/10 of the "Center Frequency Stepsize".

"0.1*Span"

The stepsize is 10 % of the current span.
"0.5*Span"
"x*Span"

"= Center"
"= Marker"

"Manual"
Remote command:

Stepsize coupling:

[SENSe:]FREQuency:CENTer:STEP:LINK on page 89

Manual stepsize as a function of the span:

[SENSe:]FREQuency:CENTer:STEP:LINK:FACTor on page 89

Manual stepsize in Hz:

[SENSe:]FREQuency:CENTer:STEP on page 89

Start / Stop

Defines the start and stop frequency.
For more information see Chapter 4.2.3, "Setting the Span", on page 37.
Remote command:

Start frequency:

[SENSe:]FREQuency:STARt on page 90

Stop frequency:

[SENSe:]FREQuency:STOP on page 90

The stepsize is 50 % of the current span.

The stepsize is a percentage of the current span that you can define

manually.

The stepsize is matched to the current center frequency.

The stepsize is matched to the current marker frequency.

Available only if a marker is active.

The stepsize is a fixed frequency that you define manually.

Frequency Offset

Defines a frequency offset in the range from -100 GHz to 100 GHz.
The offset shifts the displayed frequency range along the x-axis by a certain amount.
Remote command:

[SENSe:]FREQuency:OFFSet on page 90

Span Manual

Defines the frequency span.
The frequency span has a range from 100 Hz to 40 MHz. If you set a span of 0 Hz, the

R&S ESR enters the time domain.
Remote command:

[SENSe:]FREQuency:SPAN on page 90

56User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

5.3.3 Defining Level Characteristics

Configuration

Common Measurement Settings

Sweeptime Manual (F) / (T)

Defines the sweep time for measurements in the frequency domain "(F)" or time
domain "(T)".

For more information see Chapter 4.2.2, "Setting the Sweep Time", on page 36.
Remote command:

[SENSe:]SWEep:TIME on page 101

Full Span

Restore the full span of 40 MHz.
Remote command:

[SENSe:]FREQuency:SPAN:FULL on page 90

The Amplitude menu contains all functions necessary to define level characteristics
and to configure the vertical diagram axis.

For more comprehensive information on selected topics see the operating manual of
the R&S ESR.

► To access the "Amplitude" menu, press the [AMPT] key on the R&S ESR front

panel.

Ref Level.......................................................................................................................57

Range............................................................................................................................58

└ Range Log 100 dB..........................................................................................58

└ Range Log 50 dB............................................................................................58

└ Range Log 10 dB............................................................................................58

└ Range Log 5 dB..............................................................................................59

└ Range Log 1 dB..............................................................................................59

└ Range Log Manual..........................................................................................59

└ Range Linear %.............................................................................................. 59

└ Range Lin. Unit............................................................................................... 59

Unit................................................................................................................................60

Preamp On/Off..............................................................................................................60

RF Atten Manual/Mech Att Manual............................................................................... 60

RF Atten Auto/Mech Att Auto........................................................................................61

Ref Level Offset.............................................................................................................61

Ref Level Position......................................................................................................... 61

Grid Abs/Rel .................................................................................................................61

Noise Correction........................................................................................................... 61

Input (AC/DC)................................................................................................................62

Input 50 Ω/75 Ω ............................................................................................................62

Ref Level

Opens an edit dialog box to enter the reference level in the current unit (dBm, dBµV,
etc).

57User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

The reference level is the maximum value the AD converter can handle without distor­tion of the measured value. Signal levels above this value will not be measured cor­rectly, which is indicated by the "IFOVL" status display.

Remote command:

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel on page 93

Range

Opens a submenu to define the display range of the level axis.

●

Range Log 100 dB

●

Range Log 50 dB

●

Range Log 10 dB

●

Range Log 5 dB

●

Range Log 1 dB

●

Range Log Manual

●

Range Linear %

●

Range Lin. Unit

Range Log 100 dB ← Range

Sets the level display range to 100 dB.
Remote command:

Logarithmic scaling:

DISP:WIND:TRAC:Y:SPAC LOG, see DISPlay[:WINDow<n>]:TRACe<t>:Y:

SPACing on page 95

Display range:
DISP:WIND:TRAC:Y 100DB, see DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]
on page 93

Range Log 50 dB ← Range

Sets the level display range to 50 dB.
Remote command:

Logarithmic scaling:

DISP:WIND:TRAC:Y:SPAC LOG, see DISPlay[:WINDow<n>]:TRACe<t>:Y:

SPACing on page 95

Display range:
DISP:WIND:TRAC:Y 50DB, see DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]
on page 93

Range Log 10 dB ← Range

Sets the level display range to 10 dB.
Remote command:

Logarithmic scaling:

DISP:WIND:TRAC:Y:SPAC LOG, see DISPlay[:WINDow<n>]:TRACe<t>:Y:

SPACing on page 95

Display range:
DISP:WIND:TRAC:Y 10DB, see DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]
on page 93

58User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

Range Log 5 dB ← Range

Sets the level display range to 5 dB.
Remote command:

Logarithmic scaling:

DISP:WIND:TRAC:Y:SPAC LOG, see DISPlay[:WINDow<n>]:TRACe<t>:Y:

SPACing on page 95

Display range:
DISP:WIND:TRAC:Y 5DB, see DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]
on page 93

Range Log 1 dB ← Range

Sets the level display range to 1 dB.
Remote command:

Logarithmic scaling:

DISP:WIND:TRAC:Y:SPAC LOG, see DISPlay[:WINDow<n>]:TRACe<t>:Y:

SPACing on page 95

Display range:
DISP:WIND:TRAC:Y 1DB, see DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]
on page 93

Range Log Manual ← Range

Opens an edit dialog box to define the display range of a logarithmic level axis man­ually.

Remote command:
Logarithmic scaling:

DISP:WIND:TRAC:Y:SPAC LOG, see DISPlay[:WINDow<n>]:TRACe<t>:Y:

SPACing on page 95

Display range:

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe] on page 93

Range Linear % ← Range

Selects linear scaling for the level axis in %.
The grid is divided into decadal sections.
Markers are displayed in the selected unit ("Unit" softkey). Delta markers are displayed

in % referenced to the voltage value at the position of marker 1. This is the default set­ting for linear scaling.

Remote command:
DISP:TRAC:Y:SPAC LIN, see DISPlay[:WINDow<n>]:TRACe<t>:Y:SPACing
on page 95

Range Lin. Unit ← Range

Selects linear scaling in dB for the level display range, i.e. the horizontal lines are
labeled in dB.

Markers are displayed in the selected unit ("Unit" softkey). Delta markers are displayed
in dB referenced to the power value at the position of marker 1.

59User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

Remote command:
DISP:TRAC:Y:SPAC LDB, see DISPlay[:WINDow<n>]:TRACe<t>:Y:SPACing
on page 95

Unit

Opens the "Unit" submenu to select the unit for the level axis.
The default setting in spectrum mode is dBm.
If a transducer is switched on, the softkey is not available.
In general, the signal analyzer measures the signal voltage at the RF input. The level

display is calibrated in RMS values of an unmodulated sine wave signal. In the default
state, the level is displayed at a power of 1 mW (= dBm). Via the known input impe­dance (50 Ω or 75 Ω), conversion to other units is possible. The following units are
available and directly convertible:

●

dBm

●

dBmV

●

dBμV

●

dBμA

●

dBpW

●

Volt

●

Ampere

●

Watt

Remote command:

CALCulate<n>:UNIT:POWer on page 92

Preamp On/Off

Switches the preamplifier on and off.
Remote command:

INPut:GAIN:STATe on page 96

RF Atten Manual/Mech Att Manual

Opens an edit dialog box to enter the attenuation, irrespective of the reference level. If
electronic attenuation is activated (option R&S FSV-B25 only; "El Atten Mode Auto"
softkey), this setting defines the mechanical attenuation.

The mechanical attenuation can be set in 10 dB steps.
The RFattenuation can be set in 5 dB steps (with option R&S FSV-B25: 1 dB steps). If

the defined reference level cannot be set for the set RF attenuation, the reference level
is adjusted accordingly.

The RF attenuation defines the level at the input mixer according to the formula:
level

mixer

= level

– RF attenuation

input

Note: The maximum mixer level allowed is 0 dBm. Mixer levels above this value may
lead to incorrect measurement results, which are indicated by the "OVLD" status dis­play. The increased mixer level allows for an improved signal, but also increases the
risk of overloading the instrument!

Remote command:

INPut:ATTenuation on page 95

60User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

RF Atten Auto/Mech Att Auto

Sets the RF attenuation automatically as a function of the selected reference level.
This ensures that the optimum RF attenuation is always used. It is the default setting.

Remote command:

INPut:ATTenuation:AUTO on page 96

Ref Level Offset

Opens an edit dialog box to enter the arithmetic level offset. This offset is added to the
measured level irrespective of the selected unit. The scaling of the y-axis is changed
accordingly. The setting range is ±200 dB in 0.1 dB steps.

Remote command:

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel:OFFSet on page 94

Ref Level Position

Opens an edit dialog box to enter the reference level position, i.e. the position of the
maximum AD converter value on the level axis. The setting range is from -200 to
+200 %, 0 % corresponding to the lower and 100 % to the upper limit of the diagram.

Remote command:

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RPOSition on page 94

Grid Abs/Rel

Switches between absolute and relative scaling of the level axis (not available with
"Linear" range).

"Abs"

"Rel"

Remote command:

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:MODE on page 93

Noise Correction

If activated, the results are corrected by the instrument's inherent noise, which increa­ses the dynamic range.

"ON"

"OFF"
"AUTO"

Absolute scaling: The labeling of the level lines refers to the absolute
value of the reference level. Absolute scaling is the default setting.

Relative scaling: The upper line of the grid is always at 0 dB. The
scaling is in dB whereas the reference level is always in the set unit
(for details on unit settings see the "Unit" softkey).

A reference measurement of the instrument's inherent noise is carried
out. The noise power measured is then subtracted from the power in
the channel that is being examined.
The inherent noise of the instrument depends on the selected center
frequency, resolution bandwidth and level setting. Therefore, the cor­rection function is disabled whenever one of these parameters is
changed. A disable message is displayed on the screen. Noise cor­rection must be switched on again manually after the change.

No noise correction is performed.
Noise correction is performed. After a parameter change, noise cor-

rection is restarted automatically and a new correction measurement
is performed.

61User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

Remote command:

[SENSe:]POWer:NCORrection on page 97

Input (AC/DC)

Toggles the RF input of the R&S ESR between AC and DC coupling.
Remote command:

INPut:COUPling on page 96

Input 50 Ω/75 Ω

Uses 50 Ω or 75 Ω as reference impedance for the measured levels. Default setting is
50 Ω.

The setting 75 Ω should be selected if the 50 Ω input impedance is transformed to a
higher impedance using a 75 Ω adapter of the RAZ type (= 25 Ω in series to the input
impedance of the instrument). The correction value in this case is 1.76 dB = 10 log (75
Ω/50 Ω).

All levels specified in this Operating Manual refer to the default setting of the instru­ment (50 Ω).

Remote command:

INPut:IMPedance on page 96

5.3.4 Selecting the Measurement Bandwidth

The "Bandwidth" menu contains all functions necessary to configure the measurement
bandwidth.

► To access the "Bandwidth" menu, press the [BW] key on the R&S ESR front panel.

Res BW Manual............................................................................................................ 62

Sweeptime Manual (F) / (T) / Auto................................................................................62

Coupling Ratio...............................................................................................................63

Res BW Manual

Defines the resolution bandwidth.
For more information see Chapter 4.2, "Configuring Realtime Measurements",

on page 35.
Remote command:

[SENSe:]BANDwidth|BWIDth[:RESolution] on page 91
[SENSe:]BANDwidth|BWIDth[:RESolution]:AUTO on page 91

Sweeptime Manual (F) / (T) / Auto

Defines the sweep time for measurements in the frequency domain "(F)" or time
domain "(T)".

You can define the sweep time manually or automatically.
For more information see Chapter 4.2.2, "Setting the Sweep Time", on page 36.

62User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

5.3.5 Triggering Measurements

Configuration

Common Measurement Settings

Remote command:

[SENSe:]SWEep:TIME on page 101
[SENSe:]SWEep:TIME:AUTO on page 101

Coupling Ratio

Opens a submenu to define a fix coupling ratio between resolution bandwidth and
span.

The following coupling ratios are available.

●

Span / RBW 3333

●

Span / RBW 1666

●

Span / RBW 833

●

Span / RBW 416

●

Span / RBW 208

Remote command:

[SENSe:]BANDwidth|BWIDth[:RESolution]:RATio on page 92

► To access the "Trigger" menu, press the [TRIG] key on the R&S ESR front panel.

Free Run....................................................................................................................... 63

External.........................................................................................................................63

Frequency Mask............................................................................................................63

Time Domain.................................................................................................................64

Pretrigger / Posttrigger..................................................................................................64

Auto Rearm...................................................................................................................64

Stop On Trigger.............................................................................................................64

Free Run

The start of a sweep is not triggered. Once a measurement is completed, another is
started immediately.

Remote command:
TRIG:SOUR IMM, see TRIGger<n>[:SEQuence]:SOURce on page 103

External

Defines triggering via a TTL signal at the "EXT TRIG/GATE IN" input connector on the
rear panel.

Remote command:
TRIG:SOUR EXT, see TRIGger<n>[:SEQuence]:SOURce on page 103

Frequency Mask

Opens a submenu to configure the frequency mask trigger.
For more information see Chapter 4.3.1, "Working with the Frequency Mask Trigger",

on page 38.

63User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Configuration

Common Measurement Settings

Remote command:
see Chapter 7.3.5.2, "Using the Frequency Mask Trigger", on page 105

Time Domain

Selects the time domain trigger.
For more information see Chapter 4.3.2, "Using the Time Domain Trigger", on page 43.
Remote command:

TRIGger<n>[:SEQuence]:TDTRigger:LEVel on page 104

Pretrigger / Posttrigger

Defines a pre- and posttrigger period that is included in the data analysis.
For more information see Chapter 4.3.4, "Using Pre- and Posttrigger", on page 43.

Auto Rearm

Immediately rearms the trigger after a measurement has been triggered.
Any further trigger events trigger a new measurement. Displayed data will be overwrit-

ten.
Remote command:

TRIGger:MODE on page 102

Stop On Trigger

Stops the measurement after a measurements has been triggered.
Any further trigger events are ignored. Displayed data remains.
Remote command:

TRIGger:MODE on page 102

64User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

6 Analysis

6.1 Working with Traces

Analysis

Working with Traces

Trace 1 to 4...................................................................................................................65

└ Clear Write......................................................................................................65

└ Max Hold.........................................................................................................65

└ Min Hold..........................................................................................................66

└ View................................................................................................................ 66

└ Blank...............................................................................................................66

└ Detector.......................................................................................................... 66

└ Positive Peak........................................................................................66

└ Negative Peak...................................................................................... 66

└ Average................................................................................................ 67

Copy Trace....................................................................................................................67

Trace Wizard.................................................................................................................67

ASCII Trace Export....................................................................................................... 67

Decim Sep.....................................................................................................................67

Trace 1 to 4

Selects the active trace (1, 2, 3 or 4) and opens the "Trace Mode" submenu for the
selected trace.

Note that in Spectrum mode, 6 traces are available.
The default setting is trace 1 in the overwrite mode (see "Clear Write" on page 65),

the other traces are switched off (see "Blank" on page 66).
Tip: To configure several traces in one step, use the functionality of the Trace Configu-

ration dialog box. To access the dialog box, press the Trace Wizard softkey.
Note that in the Spectrogram and Persistence Spectrum result displays only one trace

is available. In the Persistence Spectrum, this is the Realtime trace.
Remote command:

Selected via numeric suffix of:TRACe<n> commands

Clear Write ← Trace 1 to 4

Overwrite mode: the trace is overwritten by each sweep. This is the default setting.
Remote command:

DISP:TRAC:MODE WRIT, see DISPlay[:WINDow<n>]:TRACe<t>:MODE
on page 112

Max Hold ← Trace 1 to 4

The maximum value is determined over several sweeps and displayed. The R&S ESR
saves the sweep result in the trace memory only if the new value is greater than the
previous one.

This mode is especially useful with modulated or pulsed signals. The signal spectrum
is filled up upon each sweep until all signal components are detected in a kind of enve­lope.

65User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Analysis

Working with Traces

Remote command:
DISP:TRAC:MODE MAXH, see DISPlay[:WINDow<n>]:TRACe<t>:MODE
on page 112

Min Hold ← Trace 1 to 4

The minimum value is determined from several measurements and displayed. The
R&S ESR saves the smallest of the previously stored/currently measured values in the
trace memory.

This mode is useful e.g. for making an unmodulated carrier in a composite signal visi­ble. Noise, interference signals or modulated signals are suppressed whereas a CW
signal is recognized by its constant level.

Remote command:
DISP:TRAC:MODE MINH, see DISPlay[:WINDow<n>]:TRACe<t>:MODE
on page 112

View ← Trace 1 to 4

The current contents of the trace memory are frozen and displayed.
Note: If a trace is frozen, the instrument settings, apart from level range and reference

level (see below), can be changed without impact on the displayed trace. The fact that
the displayed trace no longer matches the current instrument setting is indicated by the

icon on the tab label.

If the level range or reference level is changed, the R&S ESR automatically adapts the
measured data to the changed display range. This allows an amplitude zoom to be
made after the measurement in order to show details of the trace.

Remote command:
DISP:TRAC:MODE VIEW, see DISPlay[:WINDow<n>]:TRACe<t>:MODE
on page 112

Blank ← Trace 1 to 4

Hides the selected trace.
Remote command:

DISP:TRAC OFF, see DISPlay[:WINDow<n>]:TRACe<t>[:STATe] on page 113

Detector ← Trace 1 to 4

Opens a submenu to select the detector.

Positive Peak ← Detector ← Trace 1 to 4

Selects the "Positive Peak" detector.
Remote command:

DET POS, see [SENSe:][WINDow:]DETector<trace>[:FUNCtion] on page 115

Negative Peak ← Detector ← Trace 1 to 4

Selects the "Negative Peak" detector.
Remote command:

DET NEG, see [SENSe:][WINDow:]DETector<trace>[:FUNCtion] on page 115

66User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Analysis

Working with Traces

Average ← Detector ← Trace 1 to 4

Selects the "Average" detector.
Remote command:

DET AVER, see [SENSe:][WINDow:]DETector<trace>[:FUNCtion]
on page 115

Copy Trace

Opens an edit dialog box to enter the number of the trace memory in which the cur­rently selected trace will be copied.

Remote command:

TRACe<n>:COPY on page 115

Trace Wizard

Opens the Trace Wizard dialog. For more information see the manual of the R&S ESR.

ASCII Trace Export

Opens the "ASCII Trace Export Name" dialog box and saves the active trace in ASCII
format to the specified file and directory.

Tip: You can export a single trace ("ASCII Trace Export Trace (x)" softkey) or all traces
at the same time ("ASCII Trace Export All Traces"). When you use single trace export,
the R&S ESR exports the currently selected trace (indicated by the softkey label). Note
that the exported ASCII file has a slightly different structure compared to a single trace
export.

The file consists of the header containing important scaling parameters and a data sec­tion containing the trace data. For details on an ASCII file see Chapter 4.6, "ASCII File

Export Format", on page 47.

This format can be processed by spreadsheet calculation programs, e.g. MS-Excel. It
is necessary to define ';' as a separator for the data import. Different language versions
of evaluation programs may require a different handling of the decimal point. It is there­fore possible to select between separators '.' (decimal point) and ',' (comma) using the
"Decim Sep" softkey (see "Decim Sep" on page 67).

Remote command:

FORMat:DEXPort:TRACes on page 114
FORMat:DEXPort:DSEParator on page 114
MMEMory:STORe<n>:TRACe on page 114

Decim Sep

Selects the decimal separator with floating-point numerals for the ASCII Trace export
to support evaluation programs (e.g. MS-Excel) in different languages. The values '.'
(decimal point) and ',' (comma) can be set.

Remote command:

FORMat:DEXPort:DSEParator on page 114

67User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

6.2 Using Markers

6.2.1 Configuring Markers

Analysis

Using Markers

Marker 1 / Marker 2 / Marker 3 / … Marker 16,/ Marker Norm/Delta............................ 68

More Markers................................................................................................................68

(Current Maxhold)......................................................................................................... 68

Marker to Trace.............................................................................................................69

Marker Wizard...............................................................................................................69

└ All Marker Off..................................................................................................70

All Marker Off................................................................................................................ 70

Marker Table................................................................................................................. 70

Marker Stepsize............................................................................................................ 70

└ Stepsize Standard...........................................................................................70

└ Stepsize Sweep Points................................................................................... 71

Marker Info (On Off)......................................................................................................71

Marker 1 / Marker 2 / Marker 3 / … Marker 16,/ Marker Norm/Delta

The "Marker X" softkey activates the corresponding marker and opens an edit dialog
box to enter a value for the marker to be set to. Pressing the softkey again deactivates
the selected marker.

If a marker value is changed using the rotary knob, the step size is defined via the

Stepsize Standard or Stepsize Sweep Points softkeys.

Marker 1 is always the reference marker for relative measurements. If activated, mark­ers 2 to 16 are delta markers that refer to marker 1. These markers can be converted
into markers with absolute value display using the "Marker Norm/Delta" softkey. If
marker 1 is the active marker, pressing the "Marker Norm/Delta" softkey switches on
an additional delta marker.

Remote command:

CALCulate<n>:MARKer<m>[:STATe] on page 118
CALCulate<n>:MARKer<m>:X on page 119
CALCulate<n>:MARKer<m>:Y on page 120
CALCulate<n>:DELTamarker<m>[:STATe] on page 122
CALCulate<n>:DELTamarker<m>:X on page 123
CALCulate<n>:DELTamarker<m>:X:RELative? on page 123
CALCulate<n>:DELTamarker<m>:Y on page 124

More Markers

Opens a sub-menu to select one of up to 16 available markers. See "Marker 1 / Marker

2 / Marker 3 / … Marker 16,/ Marker Norm/Delta" on page 68.

(Current Maxhold)

Selects the trace (current ot maxhold) the marker is positioned on.
Available for the persistence spectrum.

68User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Analysis

Using Markers

Remote command:

CALCulate<n>:MARKer<m>:TRACe on page 118

Marker to Trace

Opens an edit dialog box to enter the number of the trace on which the marker is to be
placed.

Remote command:

CALCulate<n>:MARKer<m>:TRACe on page 118
CALCulate<n>:DELTamarker<m>:TRACe on page 122

Marker Wizard

Opens a configuration dialog for markers. The marker wizard allows you to configure
and activate up to 16 different markers in one dialog. The first 8 markers are displayed
on one tab, the last 8 markers on a second tab. For each marker, the following settings
are available:

"Selected/
State"

"Normal/Delta"

"Ref. Marker"

"Trace"
Remote command:

CALCulate<n>:MARKer<m>[:STATe] on page 118
CALCulate<n>:DELTamarker<m>[:STATe] on page 122

When you press the "Selected" or "State" field the corresponding
marker is activated and the marker row is highlighted.

Defines whether it is a normal marker or delta marker. For delta mark­ers you can define a reference marker.

Reference marker for delta markers. The marker values for the delta
marker are indicated relative to the specified reference marker.

Trace for which the marker is to be set.

69User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Analysis

Using Markers

CALCulate<n>:MARKer<m>:TRACe on page 118
CALCulate<n>:DELTamarker<m>:TRACe on page 122
CALCulate<n>:DELTamarker<m>:MREF on page 122

All Marker Off ← Marker Wizard

Switches all markers off. It also switches off all functions and displays that are associ­ated with the markers/delta markers.

Remote command:

CALCulate<n>:MARKer<m>:AOFF on page 117

All Marker Off

Switches all markers off. It also switches off all functions and displays that are associ­ated with the markers/delta markers.

Remote command:

CALCulate<n>:MARKer<m>:AOFF on page 117

Marker Table

Defines how the marker information is displayed.
"On"

"Off"
"Aut"

Remote command:

DISPlay:MTABle on page 125

Displays the marker information in a table in a separate area beneath
the diagram.

Displays the marker information within the diagram area.
(Default) The marker table is displayed automatically if more than 2

markers are active, and removed if only 1 or 2 markers are active.
This helps keep the information in the display clear.

Marker Stepsize

Opens a submenu to set the step size of all markers and delta markers.
Default value for the marker step size is Stepsize Sweep Points.

Stepsize Standard ← Marker Stepsize

Moves the marker or delta marker from one measurement point to the next, if the
marker or delta marker value is changed via the rotary knob ( "Marker 1 / Marker 2 /
Marker 3 / … Marker 16,/ Marker Norm/Delta" softkeys, see "Marker 1 / Marker 2 /

Marker 3 / … Marker 16,/ Marker Norm/Delta" on page 68). If more measured values

than measurement points exist, it is not possible to read out all measured values. In
this case, use the Stepsize Sweep Points softkey.

Remote command:
CALC:MARK:X:SSIZ STAN (see CALCulate<n>:MARKer<m>:X:SSIZe
on page 119)

70User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

6.2.2 Positioning Markers

Analysis

Using Markers

Stepsize Sweep Points ← Marker Stepsize

Moves the marker or delta marker from one measured value to the next, if the marker
or delta marker value is changed via the rotary knob ( "Marker 1 / Marker 2 / Marker 3 /
… Marker 16,/ Marker Norm/Delta" softkeys, see "Marker 1 / Marker 2 / Marker 3 / …

Marker 16,/ Marker Norm/Delta" on page 68). If more measured values than measure-

ment points exist, every single measured value is accessible and its value is displayed
in the marker field.

The number of measured values is defined by the measurement bandwidth.
Remote command:

CALC:MARK:X:SSIZ POIN (see CALCulate<n>:MARKer<m>:X:SSIZe
on page 119)

Marker Info (On Off)

Turns the display of the marker information in the diagram area on and off.

Peak..............................................................................................................................71

Next Peak......................................................................................................................71

Center =Mkr Freq (span > 0).........................................................................................72

Ref Lvl =Mkr Lvl............................................................................................................ 72

Marker to Trace.............................................................................................................72

Min................................................................................................................................ 72

Next Min........................................................................................................................72

Auto Max Peak/Auto Min Peak..................................................................................... 72

Search Limits................................................................................................................ 72

└ Left Limit......................................................................................................... 73

└ Right Limit.......................................................................................................73

└ Threshold........................................................................................................73

└ Use Zoom Limits.............................................................................................73

└ Search Lim Off................................................................................................73

Next Mode.....................................................................................................................73

Exclude LO....................................................................................................................74

Peak

Sets the active marker/delta marker to the highest maximum of the trace.
Remote command:

CALCulate<n>:MARKer<m>:MAXimum[:PEAK] on page 127

Next Peak

Sets the active marker/delta marker to the next maximum of the selected trace.
Remote command:

CALCulate<n>:MARKer<m>:MAXimum:NEXT on page 127
CALCulate<n>:DELTamarker<m>:MAXimum:NEXT on page 137

71User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Analysis

Using Markers

Center =Mkr Freq (span > 0)

Sets the center frequency to the current marker or delta marker frequency. A signal
can thus be set to as center frequency, for example to examine it in detail with a
smaller span.

Remote command:

CALCulate<n>:MARKer<m>:FUNCtion:CENTer on page 125

Ref Lvl =Mkr Lvl

Sets the reference level to the current marker level.
Remote command:

CALCulate<n>:MARKer<m>:FUNCtion:REFerence on page 126

Marker to Trace

Opens an edit dialog box to enter the number of the trace on which the marker is to be
placed.

Remote command:

CALCulate<n>:MARKer<m>:TRACe on page 118
CALCulate<n>:DELTamarker<m>:TRACe on page 122

Min

Sets the active marker/delta marker to the minimum of the selected trace.
Remote command:

CALCulate<n>:MARKer<m>:MINimum[:PEAK] on page 130

Next Min

Sets the active marker/delta marker to the next minimum of the selected trace.
Remote command:

CALCulate<n>:MARKer<m>:MINimum:NEXT on page 129
CALCulate<n>:DELTamarker<m>:MINimum:NEXT on page 139

Auto Max Peak/Auto Min Peak

Adds an automatic peak search action for marker 1 at the end of each particular
sweep. This function may be used during adjustments of a device under test to keep
track of the current peak marker position and level.

The current marker search limit settings (Left Limit, Right Limit, Threshold softkeys) are
taken into account.

Remote command:

CALCulate<n>:MARKer<m>:MAXimum:AUTO on page 126
CALCulate<n>:MARKer<m>:MINimum:AUTO on page 128

Search Limits

Opens a submenu to set the limits for maximum or minimum search in the x and y
direction.

Remote command:

CALCulate<n>:MARKer<m>:X:SLIMits[:STATe] on page 148

72User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Analysis

Using Markers

Left Limit ← Search Limits

Opens an edit dialog box to enter a value for the lower limit (left vertical line: S1 for
span > 0; T1 for zero span). The search is performed between the lines of the left and
right limit (see also Right Limit softkey).

Remote command:

CALCulate<n>:MARKer<m>:X:SLIMits:LEFT on page 147

Right Limit ← Search Limits

Opens an edit dialog box to enter a value for the upper limit (left vertical line: S2 for
span > 0; T2 for zero span). The search is performed between the lines of the left and
right limit (see also Left Limit softkey). If no value is set, the upper limit corresponds to
the stop frequency.

Remote command:

CALCulate<n>:MARKer<m>:X:SLIMits:RIGHT on page 147

Threshold ← Search Limits

Opens an edit dialog box to define the threshold line. The threshold line represents the
lower level limit for a "Peak" search and the upper level limit for a "Min" search.

Remote command:

CALCulate<n>:THReshold:STATe on page 149
CALCulate<n>:THReshold on page 149

Use Zoom Limits ← Search Limits

Restricts the marker search to the zoomed area.
Note that the marker zoom is only available in Spectrum mode.
Remote command:

CALCulate<n>:MARKer<m>:X:SLIMits:ZOOM on page 148

Search Lim Off ← Search Limits

Deactivates all limits of the search range.
Remote command:

CALCulate<n>:MARKer<m>:X:SLIMits[:STATe] on page 148
CALCulate<n>:THReshold:STATe on page 149

Next Mode

Selects the mode of the Next Peak or Next Min softkey.
Three settings are available:
"<"

"abs"

">"

Sets the active marker/delta marker to the next maximum/minimum
left to the marker of the selected trace.

Sets the active marker/delta marker to the next lower maximum/
higher minimum of the selected trace.

Sets the active marker/delta marker to the next maximum/minimum
right to the marker of the selected trace.

73User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Analysis

Using Markers

Remote command:

Next Peak:

CALC:MARK:MAX:LEFT (<): CALCulate<n>:MARKer<m>:MAXimum:LEFT
on page 127

CALCulate<n>:DELTamarker<m>:MAXimum:LEFT on page 137

CALC:MARK:MAX:RIGH (>): CALCulate<n>:MARKer<m>:MAXimum:RIGHt

on page 128

CALCulate<n>:DELTamarker<m>:MAXimum:RIGHt on page 138

CALC:DELT:MAX:NEXT (abs): CALCulate<n>:MARKer<m>:MAXimum:NEXT

on page 127

CALCulate<n>:DELTamarker<m>:MAXimum:NEXT on page 137

Next Min:

CALC:MARK:MIN:LEFT (>): CALCulate<n>:MARKer<m>:MINimum:LEFT
on page 129

CALCulate<n>:DELTamarker<m>:MINimum:LEFT on page 139

CALC:MARK:MIN:RIGH (>): CALCulate<n>:MARKer<m>:MINimum:RIGHt

on page 130

CALCulate<n>:DELTamarker<m>:MINimum:RIGHt on page 140

CALC:MARK:MIN:NEXT (abs): CALCulate<n>:MARKer<m>:MINimum:NEXT

on page 129

CALCulate<n>:DELTamarker<m>:MINimum:NEXT on page 139

Exclude LO

Switches the frequency range limit for the marker search functions on or off.
"ON"

"OFF"

Remote command:

CALCulate<n>:MARKer<m>:LOEXclude on page 117

The minimum frequency included in the peak search range is ≥ 5 ×
resolution bandwidth (RBW).
Due to the interference by the first local oscillator to the first inter­mediate frequency at the input mixer, the LO is represented as a sig­nal at 0 Hz. To avoid the peak marker jumping to the LO signal at 0
Hz, this frequency is excluded from the peak search.

No restriction to the search range. The frequency 0 Hz is included in
the marker search functions.

74User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

7 Remote Control Commands

7.1 Selecting the Operating Mode

Remote Control Commands

Selecting the Operating Mode

● Selecting the Operating Mode.................................................................................75

● Measurements and Result Displays........................................................................76

● Configuration...........................................................................................................88

● Analysis................................................................................................................. 111

● Status Registers....................................................................................................149

INSTrument:CREate[:NEW].............................................................................................. 75

INSTrument:DELete......................................................................................................... 75

INSTrument[:SELect]........................................................................................................76

INSTrument:CREate[:NEW] <ChannelType>, <ChannelName>

This command adds an additional spectrum display. You can add up to three additional
spectrum displays.

Also see

●

INSTrument[:SELect] on page 76

●

INSTrument:DELete on page 75

Parameters:

<ChannelType> SANalyzer

The channel type is always SANalyzer to add a new spectrum
display.

<ChannelName> String containing the name of the channel you want to create.

Example:

INSTrument:DELete <ChannelName>

This command deletes a spectrum display.

Also see

●

INSTrument:CREate[:NEW] on page 75

INST:CRE SAN, 'Spectrum 2'

Adds a second spectrum display.

Parameters:

<ChannelName> String containing the name of the channel you want to delete.

A channel must exist in order to be able delete it.

Example:

INST:DEL 'Spectrum 4'

Deletes the fourth spectrum display.

75User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

INSTrument[:SELect] <Mode> | <ChannelName>

This command activates a new measurement channel with the defined channel type,
or selects an existing measurement channel with the specified name.

●

INSTrument:CREate[:NEW] on page 75

Parameters:

<Mode> RECeiver

Receiver mode

RTIMe

Realtime mode

SANalyzer

Spectrum mode

Spectrum 2 | Spectrum 3 | Spectrum 4

Selects one of the additional spectrum displays. The first spec­trum display is always active. You can select it with SANalyzer.
A spectrum display must exist in order to be able to select it.

*RST: RECeiver

7.2 Measurements and Result Displays

7.2.1 Configuring Real-Time Measurements

[SENSe<n>]:SWEep:FFT:WINDow:TYPE...........................................................................76

CALCulate<n>:FEED....................................................................................................... 77

DISPlay:WINDow[:SUBWindow]:ZOOM:AREA....................................................................77

DISPlay:WINDow[:SUBWindow]:ZOOM:STATe................................................................... 78

[SENSe<n>]:SWEep:FFT:WINDow:TYPE <FFTWindow>

This command selects the type of FFT window that you want to use in realtime mode.

Parameters:
<FFTWindow> BLACkharris

FLATtop

GAUSsian

HANNing

KAISerbessel

RECTangular

*RST: BLACkharris

Example:

Mode: RT

SWE:FFT:WIND:TYPE HANN

Selects the Hanning FFT window.

76User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

CALCulate<n>:FEED <ResultDisplay>

This command selects the result display in realtime mode.

Parameters:
<ResultDisplay> 'XFRequency:RFPower[:SPECtrum]'

'XFRequency[:SPECtrum]'

Selects the realtime spectrum result display.

'XFRequency:RFPower:SGRam'

'XFRequency:SGRam'

Selects the spectrogram result display.

'XFRequency:RFPower:PSPectrum'

'XFRequency:PSPectrum'

Selects the persistence spectrum result display.
*RST: SPECtrum

Example:

CALC:FEED 'XFR:PSP'

Starts the persistence spectrum result display.

Manual operation: See "Display Config" on page 50

DISPlay:WINDow[:SUBWindow]:ZOOM:AREA <StartFrequency>, <StartTime>,

<StopFrequency>, <StopTime>

This command defines the zoom area.

Before you can use this command, you have to turn the zoom on with DISPlay:

WINDow[:SUBWindow]:ZOOM:STATe on page 78.

= Start frequency and time

1
2 = Stop frequency and time
3 = Zoom area

Parameters:

<StartFrequency> Defines the start frequency of the zoom area.

The range depends on the span of the unzoomed spectrogram.

<StartTime> Defines the start time of the zoom area.

Time information in seconds is relative to the present frame.
The range corresponds to the visible spectrogram.

<StopFrequency> Defines the stop frequency of the zoom area.

The range depends on the span of the unzoomed spectrogram.

<StopTime> Defines the stop time of the zoom area.

Time information in seconds is relative to the present frame.
The range corresponds to the visible spectrogram.

77User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

Example:

DISP:WIND:ZOOM:AREA 95MHZ,-2s,105MHZ,-1s

Defines a zoom area between 95 and 105 MHz and between -1
and -2 seconds ago.

Mode: RT

Manual operation: See "Replay Zoom (On Off)" on page 50

DISPlay:WINDow[:SUBWindow]:ZOOM:STATe <State>

This command turns the spectrogram zoom on and off.

The spectrogram has to be active for the command to work.

Parameters:

<State> ON | OFF

Example:

DISP:WIND:ZOOM:STAT ON

Turns the zoom on.

Manual operation: See "Replay Zoom (On Off)" on page 50

7.2.2 Using the Persistence Spectrum Result Display

7.2.2.1 Configuring the Persistence Spectrum

DISPlay:WINDow[:SUBWindow]:TRACe:MAXHold:RESet....................................................78

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:MAXHold[:INTensity]............................. 78

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe:MAXHold:[:STATe].....................................79

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:PERSistence:DURation.........................79

DISPlay:WINDow[:SUBWindow]:TRACe:PERSistence:GRANularity......................................79

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:PERSistence[:STATe]............................80

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:SYMBol............................................... 80

DISPlay:WINDow[:SUBWindow]:TRACe:MAXHold:RESet

This command resets the maxhold trace in the persistence spectrum result display.

Usage:

Event

Mode: RT

Manual operation: See "Maxhold Reset" on page 52

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:MAXHold[:INTensity]

<intensity> | RESet

This command defines the color intensity of the maxhold persistence spectrum.

78User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

Parameters:

<intensity> Sets the color intensity of the maxhold trace.

Setting an intensity of 0 turns the maxhold off.
Range: 0 to 254

Increment: 1
*RST: 100

RESet Resets the maxhold trace.

Example:

Mode: RT

Manual operation: See "Maxhold Intensity" on page 52

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe:MAXHold:[:STATe] <boolean>

This command switches the maxhold trace in the persistence spectrum on and off.

Parameters:
<boolean> ON | OFF

Mode: RT

Manual operation: See "Maxhold Intensity" on page 52

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:PERSistence:DURation

<persistence>

DISP:WIND:TRAC:MAXH 120

Sets the color intensity of the maxhold trace to 120.

DISP:WIND:TRAC:MAXH RES

Resets the maxhold trace.

*RST: On

This command sets the duration of the persistence.

Setting the persistence to 0 turns it off.

Parameters:

<persistence> Persistance in seconds.

Range: 0 to 8
Increment: 0.001
*RST: 1 seconds
Default unit: seconds

Example:

Mode: RT

Manual operation: See "Persistence" on page 51

DISPlay:WINDow[:SUBWindow]:TRACe:PERSistence:GRANularity <Granularity>

This command sets the persistence granularity

DISP:WIND:TRAC:PERS:DUR 4.3

Sets the persistence to 4.3 seconds.

79User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

Parameters:

<Granularity> Amount of data the R&S ESR uses to build the persitence spec-

trum in seconds.
*RST: RST value

Mode: RT

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:PERSistence[:STATe]

<boolean>

This command switches persistence in the persistence spectrum on and off.

Parameters:

<boolean> ON | OFF

*RST: On

Mode: RT

Manual operation: See "Persistence" on page 51

DISPlay:WINDow<n>[:SUBWindow<m>]:TRACe<t>:SYMBol <style>

This command sets the display style of the persistence spectrum.

Parameters:

<style> DOTS

Displays the data as dots. The result is a persistence spectrum
made up out of dots.

VECTor

Interpolates the measurement points. The result is an uninter­rupted persistence spectrum.

*RST: VECTor

Example:

CALC3:FEED 'XFR:HIST'

Activates the persistence spectrum in screen 3 with a vectorial
display of the results.

DISP:WIND3:TRAC:SYMB DOTS

Displays the persistence spectrum in the third measurement
screen as dots.

Mode: RT

Manual operation: See "Style" on page 52

7.2.2.2 Working with the Color Map

DISPlay:WINDow:PSPectrum:COLor:DEFault.....................................................................81

DISPlay:WINDow:PSPectrum:COLor:LOWer......................................................................81

DISPlay:WINDow:PSPectrum:COLor:SHAPe......................................................................81

80User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

DISPlay:WINDow:PSPectrum:COLor:TRUNcate................................................................. 81

DISPlay:WINDow:PSPectrum:COLor:UPPer.......................................................................81

DISPlay:WINDow:PSPectrum:COLor[:STYLe].....................................................................82

DISPlay:WINDow:PSPectrum:COLor:DEFault

This command sets the color settings for the persistence spectrum result display to its
default state.

Usage: Event

DISPlay:WINDow:PSPectrum:COLor:LOWer <Percentage>

This command sets the lower percentage boundary of the persistence spectrum.

Parameters:

<Percentage> Statistical frequency percentage.

Range: 0 to 65,6
*RST: 0
Default unit: %

Example:

DISP:WIND:HIST:COL:LOW 10

Sets the start of the color map to 10%.

DISPlay:WINDow:PSPectrum:COLor:SHAPe <Shape>

This command defines the shape and focus of the color curve for the persistence spec­trum result display.

Parameters:

<Shape> Shape of the color curve.

Range: -1 to 1
*RST: 0

DISPlay:WINDow:PSPectrum:COLor:TRUNcate <State>

This command reduces the range of the color map of the persistence spectrum if there
are no hits at the start or end of the value range.

Parameters:
<State> ON

OFF

*RST: OFF

Example:

DISP:WIND:PSP:COL:TRUN ON

Activates truncation of the color map.

DISPlay:WINDow:PSPectrum:COLor:UPPer <Percentage>

This command sets the upper percentage boundary of the persistence spectrum.

81User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

Parameters:

<Percentage> Statistical frequency percentage.

Range: 0 to 66
*RST: 0
Default unit: %

Example:

DISPlay:WINDow:PSPectrum:COLor[:STYLe] <ColorScheme>

This command sets the color scheme for the persistance spectrum.

Parameters:
<ColorScheme> HOT

Example:

DISP:WIND:HIST:COL:UPP 95

Sets the start of the color map to 95%.

COLD

RADar

GREYscale

*RST: HOT

DISP:WIND:HIST:COL GREY

Changes the color scheme of the persistance spectrum to black
and white.

7.2.3 Using the Spectrogram Result Display

7.2.3.1 Configuring the Spectrogram

CALCulate<n>:SGRam:CLEar[:IMMediate]

This command resets the Spectrogram result display and clears the history buffer.

Suffix:

<n>

Example:

Usage: Event

Manual operation: See "Clear Spectrogram" on page 53

CALCulate<n>:SGRam:CONT <State>

This command determines whether the results of the last measurement are deleted
before starting a new measurement in single sweep mode.

.

1...4
Selects the measurement window.

CALC:SGR:CLE

Resets the result display and clears the memory.

See "Clear Spectrogram" on page 55

82User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

Suffix:

<n>

Parameters:
<State> ON | OFF

Example:

Manual operation: See "Continue Frame (On Off)" on page 54

CALCulate<n>:SGRam:FRAMe:COUNt <Frames>

This command sets the number of frames to be recorded in a single sweep.

Suffix:

<n>

.

1...4
Selects the measurement window.

*RST: OFF

INIT:CONT OFF

Selects single sweep mode.

INIT;*WAI

Starts the sweep and waits for the end of the sweep.

CALC:SGR:CONT ON

Repeats the single sweep measurement without deleting the
results of the last measurement.

.

1...4
Selects the measurement window.

Parameters:

<Frames> The maximum number of frames depends on

the .CALCulate<n>:SGRam:HDEPth on page 84
Range: 1 to depends on history depth

Increment: 1
*RST: 1

Example:

Manual operation: See "Frame Count" on page 52

CALCulate<n>:SGRam:FRAMe:SELect <Frame>

This command selects a specific frame for further analysis. The command is available
only if no measurement is running or after a single sweep has ended.

INIT:CONT OFF

Selects single sweep mode.

CALC:SGR:FRAM:COUN 200

Sets the number of frames to 200.

See "Frame Count" on page 55

83User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

Suffix:

<n>

Parameters:
<Frame> <frame_number> (if time stamp is off)

Example:

Manual operation: See "Select Frame" on page 54

CALCulate<n>:SGRam:HDEPth <HistoryDepth>

This command sets the number of frames to be stored in the R&S ESR's memory.

Suffix:

<n>

.

1...4
Selects the measurement window.

Selects the frame. The range is {0...number of recorded
frames-1}

<time> (if time stamp is on)

Time distance in seconds. It selects the frame that is x seconds
away from frame 0.

INIT:CONT OFF

Stop the continuous sweep.

CALC:SGR:FRAM:SEL -25

Selects frame number -25.

.

1...4
Selects the measurement window.

Parameters:

<HistoryDepth> The maximum number of frames depends on the number of

sweep points.
Range: 781 to 20000

Increment: 1
*RST: 3000

Example:

Manual operation: See "History Depth" on page 52

CALCulate<n>:SGRam:TSTamp:DATA? <Mode>

This command queries the time stamp of the frames.

All available frame results are returned by TRACe<n>[:DATA] on page 115.

Suffix:

<n>

Query parameters:
<Mode> CURRent

CALC:SGR:HDEP 1500

Sets the history depth to 1500.

.

1...4
Selects the measurement window.

Returns the time stamp of the current frame.

84User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

ALL

Returns the time stamps of all frames. The result are sorted in
descending order, beginning with the current frame.

Return values:

<TimeStamp> The return values consist of four values for each frame.

The first value is the date of the measurement in seconds that
have passed since 01.01.1970 in seconds. For a better resolu­tion the second value shows the additional milliseconds. This
value is also displayed on screen.
These numbers are appropiate for relative uses, but you can
also calculate the absolute date and time as displayed on the
screen.
The third and fourth value are reserved for future uses.
If the Spectrogram is empty, the command returns '0,0,0,0'

Example:

Usage: Query only

CALCulate<n>:SGRam:TSTamp[:STATe] <State>

This command activates and deactivates the time stamp.

If the time stamp is active, some commands do not address frames as numbers, but as
(relative) time values:

●

CALCulate<n>:DELTamarker<m>:SGRam:FRAMe on page 141

●

CALCulate<n>:MARKer<m>:SGRam:FRAMe on page 131

●

CALCulate<n>:SGRam:FRAMe:SELect on page 83

Suffix:

<n>

Parameters:
<State> ON | OFF

CALC:SGR:TST ON

Activates the time stamp.

CALC:SGR:TST:DATA? ALL

Returns the time stamp of all frames sorted in a descending
order.

.

1...4
Selects the measurement window.

*RST: OFF

Example:

Manual operation: See "Time Stamp (On Off)" on page 53

CALC:SGR:TST ON

Activates the time stamp.

85User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

CALCulate<n>:SGRam:X:DATA? <Data>

This command queries the scaling of the x-axis in the spectrogram.

Parameters:

<Data> CURRent

Scaling of the current spectrogram frame.

ALL

Scaling of all frames in the history of the spectrogram.

Usage: Query only

CALCulate<n>:SGRam[:STATe]

<State>

This command turns the spectrogram result display on and off.

Alternatively, you can turn on the spectrogram with CALCulate<n>:FEED on page 77.

Suffix:

<n>

.

1...4
Selects the measurement window.

Parameters:

<State> ON | OFF

*RST: OFF

Example:

CALC:SGR ON

Activates the Spectrogram result display.

MMEMory:STORe:SGRam <File>

This command exports the spectrogram data to a ASCII file.

The file contains the data for every frame in the history buffer. The data corresponding
to a particular frame begins with information about the frame number and the time that
frame was recorded.

Note that, depending on the size of the history buffer, the process of exporting the data
can take a while.

Parameters:

<File> string containing the file name of the destination file

Example:

MMEM:STOR:SGR

Copies the spectrogram data to a file.

7.2.3.2 Working with the Color Map

DISPlay:WINDow:SGRam:COLor:DEFault......................................................................... 87

DISPlay:WINDow:SGRam:COLor:LOWer...........................................................................87

DISPlay:WINDow:SGRam:COLor:SHAPe.......................................................................... 87

DISPlay:WINDow:SGRam:COLor:UPPer............................................................................87

DISPlay:WINDow:SGRam:COLor[:STYLe]......................................................................... 87

86User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Measurements and Result Displays

DISPlay:WINDow:SGRam:COLor:DEFault

This command sets the color settings for the spectrogram result display to its default
state.

Usage: Event

DISPlay:WINDow:SGRam:COLor:LOWer <Percentage>

This command sets the lower percentage boundary of the spectrogram.

Parameters:

<Percentage> Statistical frequency percentage.

Range: 0 to 66
*RST: 0
Default unit: %

Example:

DISPlay:WINDow:SGRam:COLor:SHAPe <Shape>

This command defines the shape and focus of the color curve for the spectrogram
result display.

Parameters:

<Shape> Shape of the color curve.

DISPlay:WINDow:SGRam:COLor:UPPer <Percentage>

This command sets the upper percentage boundary of the spectrogram.

Parameters:

<Percentage> Statistical frequency percentage.

DISP:WIND:SGR:COL:LOW 10

Sets the start of the color map to 10%.

Range: -1 to 1
*RST: 0

Range: 0 to 66
*RST: 0
Default unit: %

Example:

DISPlay:WINDow:SGRam:COLor[:STYLe] <ColorScheme>

This command sets the color scheme for the spectrogram.

Parameters:
<ColorScheme> HOT

DISP:WIND:SGR:COL:UPP 95

Sets the start of the color map to 95%.

Uses a color range from blue to red. Blue colors indicate low lev­els, red colors indicate high ones.

87User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

COLD

Uses a color range from red to blue. Red colors indicate low lev­els, blue colors indicate high ones.

RADar

Uses a color range from black over green to light turquoise with
shades of green in between. Dark colors indicate low levels, light
colors indicate high ones.

GRAYscale

Shows the results in shades of gray. Dark gray indicates low lev­els, light gray indicates high ones.

*RST: HOT

Example:

DISP:WIND:SGR:COL GRAY

Changes the color scheme of the spectrogram to black and
white.

7.3 Configuration

● Defining the Horizontal Diagram Axis..................................................................... 88

● Selecting the Measurement Bandwidth...................................................................91

● Defining Level Characteristics.................................................................................92

● Configuring the Sweep............................................................................................97

● Triggering Measurements..................................................................................... 102

7.3.1 Defining the Horizontal Diagram Axis

Commands related to the horizontal axis described elsewhere

[SENSe:]SWEep:TIME

●

[SENSe:]FREQuency:CENTer........................................................................................... 88

[SENSe:]FREQuency:CENTer:STEP..................................................................................89

[SENSe:]FREQuency:CENTer:STEP:LINK..........................................................................89

[SENSe:]FREQuency:CENTer:STEP:LINK:FACTor..............................................................89

[SENSe:]FREQuency:OFFSet...........................................................................................90

[SENSe:]FREQuency:SPAN..............................................................................................90

[SENSe:]FREQuency:SPAN:FULL.....................................................................................90

[SENSe:]FREQuency:STARt............................................................................................. 90

[SENSe:]FREQuency:STOP..............................................................................................90

[SENSe:]FREQuency:CENTer <Frequency>

This command defines the center frequency (frequency domain) or measuring fre­quency (time domain).

88User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Parameters:

<Frequency> Range: 0 to fmax

*RST: fmax/2
Default unit: Hz
f

is specified in the data sheet. min span is 10 Hz

max

Remote Control Commands

Configuration

Example:

FREQ:CENT 100 MHz

Manual operation: See "Center" on page 55

[SENSe:]FREQuency:CENTer:STEP

<StepSize>

This command defines the center frequency step size.

Parameters:

<StepSize> Range: 1 to fmax

*RST: 0.1 x <span value>
Default unit: Hz

Example:

FREQ:CENT:STEP 120 MHz

Manual operation: See "Center Frequency Stepsize" on page 56

[SENSe:]FREQuency:CENTer:STEP:LINK <CouplingType>

This command couples and decouples the center frequency step size to the span or
the resolution bandwidth.

Parameters:

<CouplingType> SPAN

Couples the step size to the span. Available for measurements
in the frequency domain.

RBW

Couples the step size to the resolution bandwidth. Available for
measurements in the time domain.

OFF

Decouples the step size (manual input).
*RST: SPAN

Example:

FREQ:CENT:STEP:LINK SPAN

Manual operation: See "Center Frequency Stepsize" on page 56

[SENSe:]FREQuency:CENTer:STEP:LINK:FACTor <Factor>

This command defines a step size factor if the center frequency step size is coupled to
the span or the resolution bandwidth.

Parameters:

<Factor> Range: 1 to 100

*RST: 10
Default unit: PCT

89User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

Example:

Manual operation: See "Center Frequency Stepsize" on page 56

[SENSe:]FREQuency:OFFSet <Offset>

This command defines the frequency offset.

Parameters:

<Offset> Range: -100 GHz to 100 GHz

Example:

Manual operation: See "Frequency Offset" on page 56

[SENSe:]FREQuency:SPAN

This command defines the frequency span.

Parameters:

<Span>

Example:

FREQ:CENT:STEP:LINK:FACT 20PCT

*RST: 0 Hz
Default unit: Hz

FREQ:OFFS 1GHZ

<Span>

*RST: fmax

FREQ:SPAN 10MHz

Manual operation: See "Span Manual" on page 56

[SENSe:]FREQuency:SPAN:FULL

This command sets the frequency span to its maximum.

Example:

Manual operation: See "Full Span" on page 57

[SENSe:]FREQuency:STARt <Frequency>

This command defines the start frequency for measurements in the frequency domain.

Parameters:

<Frequency> 0 to (fmax - min span)

Example:

Manual operation: See "Start / Stop" on page 56

[SENSe:]FREQuency:STOP <Frequency>

FREQ:SPAN:FULL

*RST: 0

FREQ:STAR 20MHz

This command defines the stop frequency for measurements in the frequency domain.

90User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

Parameters:

<Frequency> min span to fmax

*RST: fmax

Example:

FREQ:STOP 2000 MHz

Manual operation: See "Start / Stop" on page 56

7.3.2 Selecting the Measurement Bandwidth

Commands related to the bandwidth described elsewhere

[SENSe:]SWEep:TIME

●

[SENSe:]SWEep:TIME:AUTO

●

[SENSe:]BANDwidth|BWIDth[:RESolution]......................................................................... 91

[SENSe:]BANDwidth|BWIDth[:RESolution]:AUTO................................................................91

[SENSe:]BANDwidth|BWIDth[:RESolution]:RATio................................................................92

[SENSe:]BANDwidth|BWIDth[:RESolution] <Bandwidth>

This command defines the resolution bandwidth.

In realtime mode, the resolution bandwidth is always coupled to the span.

Parameters:

<Bandwidth> refer to data sheet

*RST: (AUTO is set to ON)

Example:

BAND 1 MHz

Sets the resolution bandwidth to 1 MHz

Manual operation: See "Res BW Manual" on page 62

[SENSe:]BANDwidth|BWIDth[:RESolution]:AUTO <State>

This command couples and decouples the resolution bandwidth to the span.

The automatic coupling adapts the resolution bandwidth to the current frequency span
according to the relationship between frequency span and resolution bandwidth.

Use [SENSe:]BANDwidth|BWIDth[:RESolution]:RATio to define the ratio
RBW/span.

Parameters:

<State> ON | OFF

*RST: ON

Example:

BAND:AUTO OFF

Switches off the coupling of the resolution bandwidth to the
span.

Manual operation: See "Res BW Manual" on page 62

91User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

[SENSe:]BANDwidth|BWIDth[:RESolution]:RATio <Ratio>

This command defines the ratio between the resolution bandwidth (Hz) and the span
(Hz).

Note that the ratio defined with the remote command (RBW/span) is reciprocal to that
of the manual operation (span/RBW).

Parameters:

<Ratio> Range: 0.0048 to 0.01

*RST: 0.0002

7.3.3

Example:

BAND:RAT 0.01

Manual operation: See "Coupling Ratio" on page 63

Defining Level Characteristics

CALCulate<n>:UNIT:POWer............................................................................................. 92

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]..................................................................... 93

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:MODE...........................................................93

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel..........................................................93

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel:OFFSet............................................. 94

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RPOSition..................................................... 94

DISPlay[:WINDow<n>]:TRACe<t>:Y:SPACing.....................................................................95

INPut:ATTenuation........................................................................................................... 95

INPut:ATTenuation:AUTO................................................................................................. 96

INPut:COUPling...............................................................................................................96

INPut:GAIN:STATe........................................................................................................... 96

INPut:IMPedance.............................................................................................................96

[SENSe:]POWer:NCORrection.......................................................................................... 97

CALCulate<n>:UNIT:POWer <Unit>

This command selects the unit of the y-axis.

The unit applies to all measurement windows.

Suffix:

<n>

.

irrelevant

Parameters:

<Unit> DBM | V | A | W | DBPW | WATT | DBUV | DBMV | VOLT |

DBUA | AMPere
*RST: dBm

Example:

CALC:UNIT:POW DBM

Sets the power unit to dBm.

Manual operation: See "Unit" on page 60

92User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe] <Range>

This command defines the display range of the y-axis with logarithmic scaling.

The command works only for a logarithmic scaling. You can select the scaling with

DISPlay[:WINDow<n>]:TRACe<t>:Y:SPACing on page 95.

Suffix:

<n>

<t> irrelevant

Parameters:

<Range> Range: 10 to 200

Example:

Manual operation: See "Range Log 100 dB" on page 58

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:MODE <Mode>

This command selects the type of scaling of the y-axis.

When SYSTem:DISPlay:UPDate is turned off, this command has no immediate
effect on the screen.

.

window; For applications that do not have more than 1 measure­ment window, the suffix <n> is irrelevant.

*RST: 100
Default unit: dB

DISP:TRAC:Y 110dB

See "Range Log 50 dB" on page 58
See "Range Log 10 dB" on page 58
See "Range Log 5 dB" on page 59
See "Range Log 1 dB" on page 59
See "Range Log Manual" on page 59

Suffix:

<n>

<t> irrelevant

Parameters:
<Mode> ABSolute

Example:

Manual operation: See "Grid Abs/Rel " on page 61

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel <ReferenceLevel>

This command defines the reference level.

.

window; For applications that do not have more than 1 measure­ment window, the suffix <n> is irrelevant.

absolute scaling of the y-axis

RELative

relative scaling of the y-axis
*RST: ABS

DISP:TRAC:Y:MODE REL

93User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

With the reference level offset ≠ 0, the value range of the reference level is modified by
the offset.

Suffix:

<n>

<t> irrelevant

Parameters:

<ReferenceLevel> The unit is variable.

Example:

Manual operation: See "Ref Level" on page 57

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel:OFFSet

This command defines a reference level offset.

Suffix:

<n>

<t> irrelevant

Parameters:

<Value> Range: -200 to 200

.

irrelevant.

Range: see datasheet
*RST: -10dBm

DISP:TRAC:Y:RLEV -60dBm

.

irrelevant.

*RST: 0
Default unit: dB

<Value>

Example:

Manual operation: See "Ref Level Offset" on page 61

DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RPOSition <Position>

This command defines the position of the reference level on the display grid..

Suffix:

<n>

<t> irrelevant

Parameters:

<Position> 0 PCT corresponds to the lower display border, 100% corre-

Example:

Manual operation: See "Ref Level Position" on page 61

DISP:TRAC:Y:RLEV:OFFS -10dB

.

Selects the measurement window.

sponds to the upper display border.
Range: 0 to 100

*RST: 100 PCT = frequency domain, 50 PCT = time

domain

Default unit: PCT

DISP:TRAC:Y:RPOS 50PCT

94User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

DISPlay[:WINDow<n>]:TRACe<t>:Y:SPACing <ScalingType>

This command selects the scaling of the y-axis.

Suffix:

<n>

<t> irrelevant

Parameters:
<ScalingType> LOGarithmic

Example:

Manual operation: See "Range Log 100 dB" on page 58

.

Selects the measurement window.

Logarithmic scaling.

LINear

Linear scaling in %.

LDB

Linear scaling in dB.
*RST: LOGarithmic

DISP:TRAC:Y:SPAC LIN

Select a linear scale.

See "Range Log 50 dB" on page 58
See "Range Log 10 dB" on page 58
See "Range Log 5 dB" on page 59
See "Range Log 1 dB" on page 59
See "Range Log Manual" on page 59
See "Range Linear %" on page 59
See "Range Lin. Unit" on page 59

INPut:ATTenuation <Value>

This command programs the input attenuator. To protect the input mixer against dam­age from overloads, the setting 0 dB can be obtained by entering numerals, not by
using the DOWN command.

The RFattenuation can be set in 5 dB steps (with option R&S FSV-B25: 1 dB steps). If
the defined reference level cannot be set for the set RF attenuation, the reference level
is adjusted accordingly.

In the default state with "Spectrum" mode, the attenuation set on the step attenuator is
coupled to the reference level of the instrument. If the attenuation is programmed
directly, the coupling to the reference level is switched off.

Parameters:

<Value> *RST: 10 dB (AUTO is set to ON)

Example:

Mode: all

Manual operation: See "RF Atten Manual/Mech Att Manual" on page 60

INP:ATT 30dB

Sets the attenuation on the attenuator to 30 dB and switches off
the coupling to the reference level.

95User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

INPut:ATTenuation:AUTO <State>

This command automatically couples the input attenuation to the reference level (state
ON) or switches the input attenuation to manual entry (state OFF).

Parameters:

<State> ON | OFF

*RST: ON

Example:

Manual operation: See "RF Atten Auto/Mech Att Auto" on page 61

INPut:COUPling <CouplingType>

Toggles the RF input of the R&S ESR between AC and DC coupling.

Parameters:

<CouplingType> AC | DC

Example:

Manual operation: See "Input (AC/DC)" on page 62

INPut:GAIN:STATe <State>

This command turns the preamplifier on and off. (For the exact amplification value, see
the data sheet).

Parameters:

<State> ON | OFF

INP:ATT:AUTO ON

Couples the attenuation set on the attenuator to the reference
level.

*RST: AC

INP:COUP DC

*RST: OFF

Example:

Manual operation: See "Preamp On/Off" on page 60

INPut:IMPedance <Impedance>

This command selects the nominal input impedance.

75 Ω should be selected if the 50 Ω input impedance is transformed to a higher impe­dance using a 75 Ω adapter of the RAZ type (= 25 Ω in series to the input impedance
of the instrument). The correction value in this case is 1.76 dB = 10 log (75Ω/50Ω).

Parameters:

<Impedance> 50 | 75

INP:GAIN:STAT ON

Turns the preamplifier on.

*RST: 50 Ω

96User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

Example:

INP:IMP 75

Manual operation: See "Input 50 Ω/75 Ω " on page 62

[SENSe:]POWer:NCORrection <Mode>

This command turns noise cancellation on and off.

If noise cancellation is on, the R&S ESR performs a reference measurement to deter­mine its inherent noise and subtracts the result from the channel power measurement
result (first active trace only).

The inherent noise of the instrument depends on the selected center frequency, resolu­tion bandwidth and level setting. Therefore, the correction function is disabled when­ever one of these parameters is changed. A corresponding message is displayed on
the screen. Noise correction must be turned on again manually after the change.

Parameters:

<Mode> ON

Performs noise correction.

OFF

Performs no noise correction.

AUTO

Performs noise correction.
After a parameter change, noise correction is restarted automati­cally and a new correction measurement is performed.

*RST: OFF

Example:

POW:NCOR ON

Manual operation: See "Noise Correction" on page 61

7.3.4 Configuring the Sweep

CALCulate<n>:SGRam:CLEar[:IMMediate].........................................................................97

CALCulate<n>:SGRam:CONT...........................................................................................98

CALCulate<n>:SGRam:FRAMe:COUNt............................................................................. 98

CALCulate<n>:SGRam:FRAMe:SELect............................................................................. 99

INITiate<n>:CONMeas..................................................................................................... 99

INITiate<n>:CONTinuous................................................................................................ 100

INITiate<n>[:IMMediate]..................................................................................................100

[SENSe:]SWEep:COUNt.................................................................................................101

[SENSe:]SWEep:TIME................................................................................................... 101

[SENSe:]SWEep:TIME:AUTO......................................................................................... 101

CALCulate<n>:SGRam:CLEar[:IMMediate]

This command resets the Spectrogram result display and clears the history buffer.

97User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

Suffix:

<n>

Example:

Usage: Event

Manual operation: See "Clear Spectrogram" on page 53

CALCulate<n>:SGRam:CONT

This command determines whether the results of the last measurement are deleted
before starting a new measurement in single sweep mode.

Suffix:

<n>

Parameters:
<State> ON | OFF

Example:

.

1...4
Selects the measurement window.

CALC:SGR:CLE

Resets the result display and clears the memory.

See "Clear Spectrogram" on page 55

<State>

.

1...4
Selects the measurement window.

*RST: OFF

INIT:CONT OFF

Selects single sweep mode.

INIT;*WAI

Starts the sweep and waits for the end of the sweep.

CALC:SGR:CONT ON

Repeats the single sweep measurement without deleting the
results of the last measurement.

Manual operation: See "Continue Frame (On Off)" on page 54

CALCulate<n>:SGRam:FRAMe:COUNt <Frames>

This command sets the number of frames to be recorded in a single sweep.

Suffix:

<n>

Parameters:

<Frames> The maximum number of frames depends on

.

1...4
Selects the measurement window.

the .CALCulate<n>:SGRam:HDEPth on page 84
Range: 1 to depends on history depth

Increment: 1
*RST: 1

98User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

Example:

Manual operation: See "Frame Count" on page 52

CALCulate<n>:SGRam:FRAMe:SELect <Frame>

This command selects a specific frame for further analysis. The command is available
only if no measurement is running or after a single sweep has ended.

Suffix:

<n>

Parameters:
<Frame> <frame_number> (if time stamp is off)

INIT:CONT OFF

Selects single sweep mode.

CALC:SGR:FRAM:COUN 200

Sets the number of frames to 200.

See "Frame Count" on page 55

.

1...4
Selects the measurement window.

Selects the frame. The range is {0...number of recorded
frames-1}

<time> (if time stamp is on)

Time distance in seconds. It selects the frame that is x seconds
away from frame 0.

Example:

Manual operation: See "Select Frame" on page 54

INITiate<n>:CONMeas

This command restarts a measurement that has been stopped in single sweep mode.

The measurement is restarted at the first sweep point.

As opposed to INITiate<n>[:IMMediate], this command does not reset traces in
maxhold, minhold or average mode. Therefore it can be used to continue measure­ments using max hold or averaging functions.

In single sweep mode, you can synchronize to the end of the measurement with *OPC,
*OPC? or *WAI. In continuous sweep mode, synchronization to the end of the mea­surement is not possible. Thus, it is not recommended that you use continuous sweep
mode in remote control, as results like trace data or markers are only valid after a sin­gle sweep end synchronization.

Suffix:

<n>

INIT:CONT OFF

Stop the continuous sweep.

CALC:SGR:FRAM:SEL -25

Selects frame number -25.

.

irrelevant

99User Manual 1175.7074.02 ─ 06

R&S®ESR-K55

Remote Control Commands

Configuration

Example:

Manual operation: See "Continue Single Sweep" on page 54

INITiate<n>:CONTinuous <State>

This command determines whether the trigger system is continuously initiated (contin­uous) or performs single measurements (single).

Suffix:

<n>

Parameters:

<State> ON | OFF

INIT:CONT OFF

Switches to single sweep mode.

DISP:WIND:TRAC:MODE AVER

Switches on trace averaging.

SWE:COUN 20

Setting the sweep counter to 20 sweeps.

INIT;*WAI

Starts the measurement and waits for the end of the 20 sweeps.

INIT:CONM;*WAI

Continues the measurement (next 20 sequences) and waits for
the end.

.

irrelevant

*RST: ON

Mode: all

Manual operation: See "Continuous Sweep Stop / Start" on page 53

INITiate<n>[:IMMediate]

The command initiates a new measurement.

In case of a single measurement, the R&S ESR stops measuring when it has reached
the end frequency. When you start a continuous measurement, it stops only if you
abort it deliberately.

If you are using trace modes MAXHold, MINHold and AVERage, previous results are
reset when you restart the measurement.

In single sweep mode, you can synchronize to the end of the measurement with *OPC,
*OPC? or *WAI. In continuous sweep mode, synchronization to the end of the mea­surement is not possible. Thus, it is not recommended that you use continuous sweep
mode in remote control, as results like trace data or markers are only valid after a sin­gle sweep end synchronization.

100User Manual 1175.7074.02 ─ 06