Rohde & Schwarz CMW-KM645 User manual

R&S®CMW-KM645
FM Stereo Radio
Firmware Applications
User Manual
User Manual
1173.9740.02 ─ 04
(;×ïX2)
Test & Measurement
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This user manual describes the following R&S®CMW options:
●R&S®CMW-KM645 (FM Stereo Radio, TX measurement)
© 2015 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: [phone] - 0
Fax: [phone]
E-mail: [email protected]
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.
The following abbreviations are used throughout this manual: R&S®CMW is abbreviated as R&S CMW.
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Contents
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Contents
1 Preface.................................................................................................... 5
1.1 How to Read Firmware Application Chapters............................................................ 5
1.1.1 General Description........................................................................................................ 5
1.1.2 Application Sheets.......................................................................................................... 6
1.1.3 GUI Reference................................................................................................................ 6
1.1.4 Programming Examples..................................................................................................6
1.1.5 Command Reference...................................................................................................... 6
2 What's New in this Revision..................................................................7
3 General Description...............................................................................8
3.1 Test Setup......................................................................................................................8
3.2 Measuring an FM Signal............................................................................................... 9
3.3 AF Filter Settings.......................................................................................................... 9
3.4 Limit Settings and Conformance Requirements......................................................10
3.4.1 RF Carrier Requirements.............................................................................................. 11
3.4.2 RF Modulation Requirements....................................................................................... 11
3.5 Measurement Results................................................................................................. 11
3.5.1 RF Carrier Results........................................................................................................ 11
3.5.2 RF Modulation Results..................................................................................................13
3.5.3 AF Measurement Results..............................................................................................15
3.5.4 Selecting and Modifying Views..................................................................................... 17
3.5.5 Common View Elements...............................................................................................17
4 GUI Reference...................................................................................... 19
4.1 Measurement Control................................................................................................. 19
4.2 Parameters and Settings............................................................................................ 19
4.2.1 Signal Routing and Analyzer Settings...........................................................................20
4.2.2 Measurement Control Settings......................................................................................22
4.2.3 Limit Settings.................................................................................................................24
4.2.4 Display Settings............................................................................................................ 25
4.3 Measurement Results................................................................................................. 26
5 Programming........................................................................................28
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Contents
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5.1 Key Features................................................................................................................28
5.2 Specifying General Measurement Settings.............................................................. 28
5.3 Specifying Measurement Control Settings...............................................................29
5.4 Specifying Limits........................................................................................................ 29
5.5 Performing Single Shot RF Measurements.............................................................. 29
5.6 Continuous and AF Measurements...........................................................................30
6 Command Reference........................................................................... 32
6.1 Conventions and General Information......................................................................32
6.1.1 MEAS<i>....................................................................................................................... 32
6.1.2 FETCh, READ and CALCulate Commands.................................................................. 32
6.1.3 Current and Statistical Results......................................................................................33
6.1.4 Values for RF Path Selection........................................................................................ 33
6.1.5 Keywords...................................................................................................................... 34
6.1.6 Reliability Indicator........................................................................................................ 34
6.2 Signal Routing and Analyzer Settings...................................................................... 37
6.3 Measurement Control and States.............................................................................. 40
6.4 Measurement Control Commands.............................................................................42
6.5 Limits............................................................................................................................48
6.6 Measurement Results................................................................................................. 51
6.6.1 RF Carrier Results........................................................................................................ 51
6.6.2 RF Modulation Results..................................................................................................54
6.6.3 AF Modulation Results.................................................................................................. 56
List of Commands................................................................................63
Index......................................................................................................65
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Preface
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1 Preface
The operation of the R&S CMW is described in several user manuals:
●The R&S CMW user manual describes the base software, common features of the
firmware applications and basic principles for manual operation and remote control.
There is a separate manual version for each R&S CMW model.
●Additional user manuals, like this document, describe the firmware applications.
There is only one version of these manuals for all R&S CMW models.
Rohde & Schwarz provides registered users a "CMW Customer Web" section on
GLORIS, the Global Rohde & Schwarz Information System: https://extranet.rohde-
schwarz.com. From this resource, you can download software updates, waveform
library updates and documentation updates, for example updates of this document.
1.1 How to Read Firmware Application Chapters
Each firmware application is described in a separate chapter. These chapters can be
read independently of each other. However, they are all organized as follows:
1. General Description
2. Application Sheets (optional)
3. GUI Reference
4. Programming Examples
5. Command Reference
The chapters "System Overview" and "Remote Control" in the R&S CMW user manual
provide additional important information independent of the individual firmware applica-
tions. The most important parts are referenced by the firmware application descrip-
tions.
1.1.1 General Description
This section provides a general description of the firmware application, independent of
a specific operation mode (manual or remote control). It gives a high-level introduction
to the capabilities of the firmware application. Background information related to the
network standard is given as far as it is directly related to administrable parameters.
For measurement applications a detailed description of measurement results and a
description of configurable limits is given, including the relation to conformance require-
ments defined in network standard specifications.
How to Read Firmware Application Chapters
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Preface
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1.1.2 Application Sheets
This optional section provides short application examples for select issues and related
background information.
1.1.3 GUI Reference
The GUI reference describes the manual operation of the firmware application via the
Graphical User Interface (GUI).
The description of a configuration dialog usually starts with a screenshot presenting the
preset values of the parameters (sometimes preset values are modified to enable hid-
den parts of a dialog). Below the screenshot all shown parameters are described. For
each single parameter a link to the corresponding command description in the "Com-
mand Reference" is provided. Ranges for numeric parameters and reset values are
given there.
For measurement results links to the corresponding command descriptions are provi-
ded (commands to retrieve the results). The measurement results are described in
detail in the "General Description".
1.1.4 Programming Examples
The programming examples show how to control and configure the firmware applica-
tion via a remote-control program and how to retrieve measurement results. The exam-
ples consist of comprehensive command sequences. You can check just a single com-
mand of a sequence to get an example for the syntax of this single command. But you
can also consider an entire sequence showing the commands in the context of a com-
mand script, under consideration of dependencies and required orders of the com-
mands.
The command sequences are written with the intention to list most commands of the
firmware application. They do not show the fastest way for a given configuration task.
The fastest way would use many reset values and omit the corresponding commands.
The examples are referenced by the command descriptions of the "Command Refer-
ence".
1.1.5 Command Reference
The command reference provides information on the remote commands of the firm-
ware application. The commands are grouped according to their function.
Each command description indicates the syntax of the command header and of the
parameters. For input parameters the allowed ranges, reset values and default units
are listed, for returned values the expected ranges and default units. Most commands
have a command form and a query form. Exceptions are marked by "Setting only",
"Query only" or "Event". Furthermore a link to the "Programming Examples" is provided
and the first software version supporting the command is indicated.
How to Read Firmware Application Chapters
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What's New in this Revision
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2 What's New in this Revision
This revision describes version 3.5.10 and later of the "FM Stereo Radio Measure-
ment" firmware application. Compared to version 3.2.10, there are only editorial
changes.
Software Version
To check your R&S CMW software version, open the "Setup" dialog and click "HW/SW
Equipment". The initial software version for each remote control command is quoted in
the reference description.
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General Description
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3 General Description
The "FM Stereo Radio Measurement" application (option R&S CMW-KM645) provides
transmitter (TX) tests on FM-modulated RF signals (called "FM signals" in the follow-
ing).
The tests cover the following FM signal properties:
●RF carrier characteristics including the carrier power, frequency error, and the fre-
quency deviation due to a composite modulating signal ("multiplex deviation")
●RF modulation characteristics including the frequency deviation due to the 19-kHz
pilot, the left and the right audio channels, and the pilot frequency error
●Characteristics of the demodulated AF baseband signal including a Total Harmonic
Distortion (THD), Signal to Noise and Distortion ratio (SINAD), and Signal to Noise
Ratio (SNR) measurement
For background information on FM signals and conformance requirements refer to the
relevant standards, e.g.:
●IEC 60315-4 (1997), Methods of measurement on radio receivers for various
classes of emission
●ITU-R Recommendation BS.450-3, Transmission standards for FM sound broad-
casting at VHF
All "FM Stereo Radio" measurements are combined in a single, multi evaluation mea-
surement group.
The following sections describe how to configure and perform the "FM Stereo Radio
Measurement".
●Test Setup.................................................................................................................8
●Measuring an FM Signal........................................................................................... 9
●AF Filter Settings.......................................................................................................9
●Limit Settings and Conformance Requirements......................................................10
●Measurement Results............................................................................................. 11
3.1 Test Setup
Connect the external RF signal source (mobile station, signal generator etc.) to one of
the bidirectional RF connectors on the front panel of the R&S CMW.
See also: "RF Connectors" in the R&S CMW user manual, chapter "Getting Started"
Test Setup
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General Description
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Fig. 3-1: Connecting an RF transmitter to the instrument
The measurement is performed in free run mode; no trigger signal is needed.
3.2 Measuring an FM Signal
After connecting your FM signal source to the R&S CMW as shown in section Test
Setup, you have to adjust the following analyzer settings to the properties of the ana-
lyzed signal:
●The analyzer "Frequency" (RF carrier frequency)
●The "Expected Nominal Power" and (optional) a "User Margin" and "External
Attenuation". Recommended values: "Expected Nominal Power" = nominal power
of the RF carrier. FM signals are transmitted at constant power (constant-envelope
signals), so the default "User Margin" of 0 dB should be sufficient.
With the settings described above, the R&S CMW is able to receive and demodulate
the FM stereo signal and obtain the essential measurement results.
The following measurements require additional settings:
●The demodulated left and right AF channel signals can be measured with different
filter settings in the AF analyzer path ("Deemphasis Filter", "Lowpass Filter", "High-
pass Filter", "Weighting Filter", "Bandpass Variable"). See section AF Filter Set-
tings.
●To determine the Total Harmonic Distortion (THD), the Signal to Noise and Distor-
tion Ratio (THD + N / SINAD), and the Signal to Noise Ratio (SNR), two fixed, sine
wave audio tones are transmitted over the left and right audio channels ("THD (N)
Freq. Left" and "THD (N) Freq. Right"). See description of "THD / SINAD / SNR
measurements" in chapter 3.5.3, "AF Measurement Results", on page 15.
3.3 AF Filter Settings
The audio receive path of the R&S CMW provides optional filter stages which affect the
AF results:
●A deemphasis filter with a time constant of either 50 μs or 75 μs. A deemphasis is
designed to decrease the magnitude of the higher frequencies with respect to the
magnitude of the lower frequencies in order to improve the overall signal-to-noise
ratio.
Measuring an FM Signal
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General Description
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A 50 μs time constant is used for FM broadcasting in Europe, North American FM
stations use a 75 μs time constant.
●An A-weighting filter defined in IEC 60651. The A-weighting filter deemphasizes
the very low and very high frequency components of the sound in a manner similar
to the frequency response of the human ear and correlates well with subjective
reactions to noise. Thus, noise levels stated in terms of dBA reflect the response of
the human ear by filtering out some of the noise in the low- and high-frequency
ranges that the ear does not detect well. The A-weighted scale commonly is used
in local ordinances and standards.
●A lowpass filter and a highpass filter with selectable cutoff frequencies. You can
use the highpass filter to eliminate a possible DC component in the audio signal
that may cause measurement inaccuracies.
●A variable bandpass filter with configurable center frequency and bandwidth.
Each of the left and right channels from the FM stereo decoder (see figure 3-7) is mea-
sured as shown below.
Fig. 3-2: Filters in the audio receive path
3.4 Limit Settings and Conformance Requirements
Conformance requirements for tests on FM signals are specified in the various stand-
ards; the following sections give an overview.
●RF Carrier Requirements........................................................................................11
●RF Modulation Requirements................................................................................. 11
Limit Settings and Conformance Requirements
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General Description
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3.4.1 RF Carrier Requirements
The RF signal consists of a carrier frequency-modulated by the composite audio sig-
nal. According to standard IEC 62106, the modulated carrier is transmitted with a maxi-
mum frequency deviation of ±75 kHz ("Multiplex Deviation, ± Peak / 2").
See also chapter 3.5.1, "RF Carrier Results", on page 11.
3.4.2 RF Modulation Requirements
During stereo broadcasts, the RF signal carries the left and right audio channels, used
to form the signals M and S, and the 19 kHz pilot tone. The RDS subcarrier frequency
is locked to the third harmonic of the pilot tone (57 kHz).
According to ITU-R Recommendation BS.450-3 and standard IEC 62106 (for RDS),
the following limits apply:
●The maximum "Pilot Deviation" is 8 % to 10 % of the maximum frequency deviation
of ±75 kHz.
●The RDS subcarrier deviation is from ±1.0 kHz to ±7.5 kHz. The recommended
best compromise is ±2.0 kHz
●The maximum deviation due to the M and S signals (Audio Deviation) is 90 % of
the maximum frequency deviation of ±75 kHz.
●The maximum frequency error of the pilot tone ("Pilot Frequency Error") is ±2 Hz.
See also chapter 3.5.2, "RF Modulation Results", on page 13.
3.5 Measurement Results
The results of the "FM Stereo Radio Measurement" are arranged in several groups.
Use the "Display" parameters to select the different views and to change their appear-
ance and contents.
●RF Carrier Results.................................................................................................. 11
●RF Modulation Results............................................................................................13
●AF Measurement Results........................................................................................15
●Selecting and Modifying Views............................................................................... 17
●Common View Elements.........................................................................................17
3.5.1 RF Carrier Results
The "RF Carrier Results" characterize the properties of the modulated RF signal.
Measurement Results
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General Description
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Fig. 3-3: FM Stereo Radio: RF Carrier Results
The table contains the following results:
●Carrier Power: Absolute power of the RF signal in dBm. The carrier power is mea-
sured in a 500 kHz IF bandwidth.
●Carrier Freq. Error: Difference between the measured RF frequency and the
selected center frequency of the analyzer ("RF Settings > Frequency"), which is
assumed to be the rated frequency of the RF channel.
●Multiplex Deviation, ± Peak / 2: Frequency deviation of the RF signal due to the
composite multiplex signal (baseband signal, including the mono and stereo sig-
nals and the pilot; see figure 3-8), half of the peak-to-peak value of the frequency
deviation.
The multiplex deviation is measured directly after the FM demodulator, before sep-
aration of the different baseband signal contributions; see figure 3-7.
●Multiplex Deviation, + Peak: Maximum frequency deviation due to the baseband
signal relative to the rated RF frequency.
●Multiplex Deviation, – Peak: Minimum frequency deviation due to the baseband
signal relative to the rated RF frequency.
●Multiplex Deviation, RMS: RMS average of the multiplex deviation over an appro-
priate time interval (moving average). If the baseband signal consists of a single
sine wave (e.g., the pilot tone with no mono and stereo signal contributions added),
the RMS multiplex deviation corresponds to the "Multiplex Deviation, ± Peak / 2"
divided by the square root of 2.
For an unmodulated carrier, the multiplex deviation is close to zero.
As shown below the peak-to-peak frequency deviation is independent of a possible
carrier frequency error.
Fig. 3-4: Definition of peak-to peak frequency error
Measurement Results
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General Description
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3.5.2 RF Modulation Results
The "RF Modulation Results" characterize the properties of the audio signal which
modulates the RF carrier (baseband signal).
Fig. 3-5: FM Stereo Radio: RF Modulation Results
The table contains the following results:
●Pilot Deviation, RMS * SQRT2: Frequency deviation of the RF signal due to the
19 kHz pilot tone in the baseband signal. The pilot tone causes a harmonic fre-
quency deviation; therefore the RMS average times the square root of 2 provides a
very accurate estimate of the peak deviation.
●RDS Deviation: Frequency deviation of the RF signal due to the signal in the
Radio Data System (RDS) band around 57 kHz.
●Audio Left Deviation, ± Peak / 2: Frequency deviation due to the left audio chan-
nel, half of the peak-to-peak value. See also figure 3-4.
●Audio Right Deviation, ± Peak / 2: Frequency deviation due to the right audio
channel, half of the peak-to-peak value.
●Pilot Frequency Error: Frequency error of the pilot signal relative to the rated fre-
quency of 19 kHz.
FM baseband spectrum
The FM stereo baseband signal is built from two audio channels L (left) and R (right)
and a pilot tone with constant frequency.
●The "mono" audio signal is the sum of the left and right channels: M = (L + R) / 2. It
occupies the frequency range between 30 Hz and 15 kHz. In a stereo transmitter
this signal is directly fed to the FM modulator.
●The "stereo" difference signal S = (L – R) / 2 modulates a 38 kHz subcarrier using
the Double Sideband Suppressed Carrier (DSSC) AM modulation scheme. The
subcarrier is suppressed in the transmitted FM signal.
●A 19 kHz "pilot tone" provides the frequency and phase reference for the 38 kHz
subcarrier in the transmitter. It is also used to recover the suppressed subcarrier in
the FM stereo decoder.
Measurement Results
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General Description
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Fig. 3-6: Principle of an FM stereo coder
A stereo decoder can separate the three signal contributions using appropriate filter
stages, add the (L + R) / 2 and (L – R) / 2 signals for the left channel ((L + R) / 2 + (L –
R) / 2 = L) and subtract them for the right channel ((L + R) / 2 – (L – R) / 2 = R). The
(simplified) principle of an FM stereo decoder is shown below. The diagram also shows
the different measuring points for the "RF Carrier", "RF Modulation", and "AF" mea-
surement results. To obtain the "Audio left / right deviation" results the left and right
channel signals are filtered as described in chapter 3.3, "AF Filter Settings", on page 9.
Fig. 3-7: FM stereo decoder with measuring points
Stereo signals are used for the transmission of audio programs over an FM channel.
The FM baseband spectrum also contains the Radio Data System (RDS) band around
the 57 kHz RDS subcarrier and the DARC (Data Radio Channel) band around the 76
kHz DARC subcarrier. RDS and DARC are used for data transmission. The RDS devi-
ation is measured and displayed together with the other frequency deviation results.
Apart from that, the RDS and DARC signals will not affect any of the "RF Carrier", "RF
Modulation", and "AF" measurement results of the R&S CMW.
Measurement Results
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The complete spectrum is shown below.
Fig. 3-8: FM baseband spectrum
3.5.3 AF Measurement Results
The "AF Results" characterize the properties of the demodulated audio signal. The
results for the left (L) and right (R) audio channels are analogous; refer to the descrip-
tion of the FM baseband spectrum in section RF Modulation Results.
Fig. 3-9: FM Stereo Radio: AF Results
The "SNR Statistics" table contains the following results:
●Weighted, RMS: Frequency deviation due to the left / right audio channel mea-
sured in the weighting filter path, RMS average over an appropriate time interval
(moving average).
●Bandpass, RMS: Frequency deviation due to the left / right audio channel mea-
sured in the bandpass path, RMS average.
●THD: Total Harmonic Distortion; see description below. The percentage and dB
results are equivalent.
●THD + N: Total harmonic distortion and noise; see description below.
Measurement Results
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●SINAD: Signal to Noise and Distortion ratio; the inverse of the THD + N, converted
to a dB value; see description below.
●SNR: Signal to Noise Ratio, see description below.
The filter settings for the audio measurements are described in chapter 3.3, "AF Filter
Settings", on page 9.
Max/Ext results
The results in the Max/Ext column correspond to the largest measured frequency devi-
ation and the largest distortions, e.g. the maximum THD but the smallest SINAD and
SNR.
THD / SINAD / SNR measurements
Harmonics are signals at an integer multiple of the fundamental frequency. The funda-
mental wave is the first harmonic, the n"th" harmonic is n times the frequency of the
fundamental wave. The production of harmonic frequencies by an electronic system
when a signal is applied at the input is known as harmonic distortion. The following fig-
ure shows the fundamental wave (labeled M1) and the 2nd to 5th harmonics measured
with a spectrum analyzer.
Fig. 3-10: Harmonics spectrum
To perform a harmonics measurement, one or two fixed, sine wave audio test tones
are transmitted over the left and right audio channels. The frequency of the test tone(s)
is specified in the "Measurement Control > AF" section of the configuration dialog
("THD (N) Freq. Left" and "THD (N) Freq. Right").
The demodulated audio signal in each of the two audio channels is the sum of three
contributions:
●Signal S: S corresponds to the power P1 of the demodulated audio signal at the
reference frequency "THD (N) Freq. Left" or "THD (N) Freq. Right".
●Distortion D: The distortion is calculated from the sum of the signal powers of the
2nd, 3rd, 4th ... harmonics:
Measurement Results
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D = P2 + P3 + P4 + ...
The R&S CMW measures up to 10 harmonics at frequencies up to 21 kHz. (Exam-
ple: with a reference frequency of 3 kHz, the distortion measurement is based on
the 2nd to 7th harmonics.)
●Noise N: The noise N is the power of the noise floor.
The sum of all three contributions S + N + D is the total received audio power. S and D
can be obtained in frequency-selective measurements. To obtain the sum N + D, the
R&S CMW uses a notch filter to eliminate the fundamental wave. To avoid suppression
of the higher harmonics, the bandwidth of the notch filter is automatically adjusted to
be smaller than the reference frequency. The final results are calculated as follows:
THD [%] = sqrt (D / S) = sqrt (V22 + V32 + V42...) / V1
THD [dB] = 20 * log(THD [%]/100)
THD + N [%] = sqrt(N + D) / sqrt(S + N + D)
SINAD [dB] = 20 * log(100/(THD + N [%]))
SNR [dB] = 10 * log(S / N) = 10 * log(V12 / N)
The R&S CMW displays THD [%] values up to 100 %. A results close to 100% may
indicate incorrect settings, e.g. a specified reference frequency which if off the actual
frequency of the transmitted test tone.
3.5.4 Selecting and Modifying Views
Use the "Display" parameters to select the views and to change the appearance and
contents of the views. The following "Display" hotkeys are available:
Hotkey Description
"Select View ..." Switch to a certain detailed view or overview.
Alternatively select a diagram in the overview and press ENTER or the
rotary knob.
Use "FM > Assign Views" to disable either the RF or AF measurements.
3.5.5 Common View Elements
Below the title bar, the view shows the most important signal routing, analyzer, and
input signal settings; see chapter 4.2.1, "Signal Routing and Analyzer Settings",
on page 20.
Statistics in the result tables
Most detailed views show tables providing a statistical evaluation of results.
Measurement Results
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The statistical values in the tables are calculated as follows:
●Current: Value of the result obtained in the last measurement interval.
●Average: Average of all "Current" values referenced to the last statistics cycle.
●Max: Largest "Current" value that the R&S CMW obtained since the start of the
measurement.
●Min: Smallest "Current" value that the R&S CMW obtained since the start of the
measurement.
●StdDev: Standard deviation of all "Current" values since the start of the measure-
ment.
All statistical results (statistical tables and "Average" or "Max" traces) are calculated
according to the general rules for statistical results.
See also: "Statistical Results" in the R&S CMW user manual, chapter "System Over-
view"
Statistic Count
Progress bar for the measurement, displayed in all detailed views. During the first sin-
gle shot after the start of the measurement, the bar shows the number of elapsed mea-
surement intervals relative to the "Statistic Count". A filled progress bar indicates that
the first shot is complete and the statistical depth has been reached.
See also: "Statistical Settings" in the R&S CMW user manual, chapter "System Over-
view"
Out of Tolerance
Percentage of measurements that were failed because they exceeded the specified
limits.
Measurement Results
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GUI Reference
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4 GUI Reference
The following sections provide detailed reference information on the Graphical User
Interface (GUI) and the parameters of the "FM Stereo Radio Measurements" firmware
application.
●Measurement Control..............................................................................................19
●Parameters and Settings.........................................................................................19
●Measurement Results............................................................................................. 26
4.1 Measurement Control
The measurement is turned on or off using the ON | OFF or RESTART | STOP keys.
See also: "Measurement Control" in the R&S CMW user manual, chapter "System
Overview"
FM (Softkey)
The softkey shows the current measurement state. Additional measurement substates
can be retrieved via remote control.
Remote command:
INITiate:FMSTereo:MEAS<i>:MEValuation
STOP:FMSTereo:MEAS<i>:MEValuation
ABORt:FMSTereo:MEAS<i>:MEValuation
FETCh:FMSTereo:MEAS<i>:MEValuation:STATe?
FETCh:FMSTereo:MEAS<i>:MEValuation:STATe:ALL?
4.2 Parameters and Settings
The most important settings of the "FM Stereo Radio Multi Evaluation" measurement
are displayed in the measurement dialog.
All settings are defined via softkeys and hotkeys or using the "FM Stereo Radio Multi
Evaluation Configuration" dialog. The configuration dialog provides parameters for the
following tasks:
●Signal Routing and Analyzer Settings.....................................................................20
●Measurement Control Settings................................................................................22
●Limit Settings...........................................................................................................24
●Display Settings...................................................................................................... 25
Measurement Control
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GUI Reference
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4.2.1 Signal Routing and Analyzer Settings
The measurement is configured using the parameters in the "FM Stereo Radio Config-
uration" dialog. The following parameters configure the RF input path.
See also: "Connection Control (Measurements)" in the R&S CMW user manual, chap-
ter "System Overview"
Fig. 4-1: FM Stereo Radio Configuration: Signal routing and analyzer settings
Scenario
Selects the measurement scenario. The measurement can be used in "Standalone"
mode, using all "FM Stereo Radio" measurement settings.
Remote command:
ROUTe:FMSTereo:MEAS<i>:SCENario?
ROUTe:FMSTereo:MEAS<i>?
RF Routing
Selects the input path for the measured RF signal, i.e. the input connector and the RX
module to be used.
Depending on your hardware configuration there may be dependencies between both
parameters. Select the RF connector first. The "Converter" parameter offers only val-
ues compatible with the selected RF connector.
Remote command:
ROUTe:FMSTereo:MEAS<i>:SCENario:SALone
External Attenuation (Input)
Defines the value of an external attenuation (or gain, if the value is negative) in the
input path. The power readings of the R&S CMW are corrected by the external attenu-
ation value.
The external attenuation value is also used in the calculation of the maximum input
power that the R&S CMW can measure.
If a correction table for frequency-dependent attenuation is active for the chosen con-
nector, then the table name and a button are displayed. Press the button to display the
table entries.
Remote command:
CONFigure:FMSTereo:MEAS<i>:RFSettings:EATTenuation
Parameters and Settings
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