® Preface R&S CMW-KM645 How to Read Firmware Application Chapters 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.
® Preface R&S CMW-KM645 How to Read Firmware Application Chapters 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).
® What's New in this Revision R&S CMW-KM645 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"...
R&S CMW-KM645 Test Setup 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: ●...
® General Description R&S CMW-KM645 Measuring an FM Signal 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...
® General Description R&S CMW-KM645 Limit Settings and Conformance Requirements 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...
® General Description R&S CMW-KM645 Measurement Results 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").
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® General Description R&S CMW-KM645 Measurement Results 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.
® General Description R&S CMW-KM645 Measurement Results 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: ●...
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® General Description R&S CMW-KM645 Measurement Results 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 –...
® General Description R&S CMW-KM645 Measurement Results 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-...
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® General Description R&S CMW-KM645 Measurement Results ● 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...
® General Description R&S CMW-KM645 Measurement Results D = P + ... 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...
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® General Description R&S CMW-KM645 Measurement Results 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.
® GUI Reference R&S CMW-KM645 Measurement Control 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...
® GUI Reference R&S CMW-KM645 Parameters and Settings 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"...
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® GUI Reference R&S CMW-KM645 Parameters and Settings Frequency Center frequency of the RF analyzer. Set this frequency to the RF carrier frequency to obtain a meaningful measurement result. Remote command: CONFigure:FMSTereo:MEAS<i>:RFSettings:FREQuency Expected Nominal Power Sets the analyzer in accordance with the nominal power of the RF signal to be mea- sured.
® GUI Reference R&S CMW-KM645 Parameters and Settings Frequency Offset Positive or negative frequency offset to be added to the specified center frequency of the RF analyzer. Remote command: CONFigure:FMSTereo:MEAS<i>:RFSettings:FOFFset 4.2.2 Measurement Control Settings The "Measurement Control" parameters configure the scope of the measurement.
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® GUI Reference R&S CMW-KM645 Parameters and Settings Single-shot is preferable if only a single measurement result is required under fixed conditions, which is typical for remote-controlled measurements. Continuous mode is suitable for monitoring the evolution of the measurement results in time and observe how they depend on the measurement configuration, which is typically done in manual control.
® GUI Reference R&S CMW-KM645 Parameters and Settings AF > AF Filter Configures the different filter stages for the AF analyzer; see chapter 3.3, "AF Filter Settings", on page 9. The AF filters (deemphasis, lowpass, highpass, weighting filter) affect all "AF Modulation" results.
® GUI Reference R&S CMW-KM645 Parameters and Settings Fig. 4-3: FM Stereo Radio limits Limits > RF Carrier Upper limits for the measurement results which characterize the RF carrier properties. An additional lower limit is specified for the RF carrier power: the carrier power must be in the range between the lower and the upper limit.
® GUI Reference R&S CMW-KM645 Measurement Results Fig. 4-4: FM Stereo Radio display settings You can also use the hotkeys associated with the "Display" softkey to select views. All display settings are self-explanatory. No remote control is provided. 4.3 Measurement Results The "FM Stereo Measurement"...
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® GUI Reference R&S CMW-KM645 Measurement Results AF Results To retrieve the AF results, use the following commands. Remote command: etc. FETCh:FMSTereo:MEAS<i>:MEValuation:AFLeft:CURRent? FETCh:FMSTereo:MEAS<i>:MEValuation:AFRight:CURRent? User Manual 1173.9740.02 ─ 04...
® Programming R&S CMW-KM645 Key Features 5 Programming The following sections provide programming examples for the "FM Stereo Radio Mea- surement" application. The examples have been tested with the aid of a simple software tool. See also: "Remote Control" in the R&S CMW user manual ●...
® Command Reference R&S CMW-KM645 Conventions and General Information 6 Command Reference The following sections provide detailed reference information on the remote con- trol commands of the "FM Stereo Radio Measurement" application. ● Conventions and General Information..............32 ● Signal Routing and Analyzer Settings..............37...
® Command Reference R&S CMW-KM645 Conventions and General Information See also: "Retrieving Measurement Results" in the R&S CMW user manual, chapter "Remote Control" 6.1.3 Current and Statistical Results The R&S CMW repeats measurements according to the selected statistic count and repetition mode.
® Command Reference R&S CMW-KM645 Conventions and General Information RB1 | RB2 | RB3 | RB4 R<m><n>: R&S CMWS connector <m>.<n> RA<n>: virtual name for R1<n> / R3<n> RB<n>: virtual name for R2<n> / R2<n+4> 6.1.5 Keywords Selected keywords used in the command description are described in the following.
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® Command Reference R&S CMW-KM645 Conventions and General Information ● 6 (Trigger Timeout): The measurement could not be started or continued because no trigger event was detected. ● 7 (Acquisition Error): The R&S CMW could not properly decode the RF input signal.
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® Command Reference R&S CMW-KM645 Conventions and General Information ● 40 (ARB File CRC Error): The ARB file CRC check failed. The ARB file is corrupt and not reliable. ● 42 (ARB Header Tag Invalid): The ARB file selected in the GPRF generator contains an invalid header tag.
® Command Reference R&S CMW-KM645 Signal Routing and Analyzer Settings ● 104 (Not Functional): The application could not be started with the configured parameter set. 6.2 Signal Routing and Analyzer Settings The following commands select the connector and configure the RF input path.
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® Command Reference R&S CMW-KM645 Signal Routing and Analyzer Settings Firmware/Software: V2.0.10 Manual operation: "Scenario" on page 20 ROUTe:FMSTereo:MEAS<i>:SCENario? Returns the active scenario. Return values: <Scenario> SALone SALone: Standalone (Non Signaling) Usage: Query only Firmware/Software: V2.0.10 Manual operation: "Scenario" on page 20 CONFigure:FMSTereo:MEAS<i>:RFSettings:EATTenuation <RFInputExtAtt>...
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® Command Reference R&S CMW-KM645 Signal Routing and Analyzer Settings Parameters: <ExpNomPwr> The range of the expected nominal power can be calculated as follows: Range (Expected Nominal Power) = Range (Input Power) + External Attenuation - User Margin Range: –55 dBm to +55 dBm for the input power at RF 1 COM and RF 2 COM (please notice also the range quoted in the data sheet).
® Command Reference R&S CMW-KM645 Measurement Control and States Parameters: <FreqOffset> Range: -100E+3 Hz to 100E+3 Hz *RST: 0 Hz Default unit: Hz Example: Specifying General Measurement Settings Firmware/Software: V3.2.10 Manual operation: "Frequency Offset" on page 22 6.3 Measurement Control and States The following commands control the measurement and return the current measure- ment state.
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® Command Reference R&S CMW-KM645 Measurement Control and States See also: "Measurement Control" in the R&S CMW user manual, chapter "Remote Control" Return values: <MeasState> OFF | RUN | RDY OFF: measurement switched off, no resources allocated, no results available (when entered after ABORt...) RUN: measurement running (after INITiate..., READ...),...
® Command Reference R&S CMW-KM645 Measurement Control Commands <ResourceState> QUE | ACT | INV QUE: measurement without resources, no results available ("queued") ACT: resources allocated, acquisition of results in progress but not complete ("active") INV: not applicable because <main_state>: OFF or RDY ("inva- lid")
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® Command Reference R&S CMW-KM645 Measurement Control Commands Example: Continuous and AF Measurements Firmware/Software: V1.0.15.20 Manual operation: "Repetition" on page 22 CONFigure:FMSTereo:MEAS<i>:SCONdition <StopCondition> Qualifies whether the measurement is stopped after a failed limit check or continued. SLFail means that the measurement is stopped and reaches the RDY state as soon as one of the results exceeds the limits.
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® Command Reference R&S CMW-KM645 Measurement Control Commands Parameters: <StatisticCount> Number of measurement intervals for the "RF Carrier" measure- ment Range: 1 to 1000 *RST: Example: Specifying Measurement Control Settings Firmware/Software: V1.0.15.20 Manual operation: "RF Carrier / RF Modulation / AF > Statistic Count"...
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® Command Reference R&S CMW-KM645 Measurement Control Commands Firmware/Software: V1.0.15.20 Manual operation: "RF Carrier / RF Modulation / AF > Statistic Count" on page 23 CONFigure:FMSTereo:MEAS<i>:MEValuation:AF:FILTer:DEEMphasis <Filter> Selects the deemphasis filter for the AF analyzer input path. Parameters: <Filter> OFF | US50 | US75 OFF: Bypass deemphasis filter stage (filter off).
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® Command Reference R&S CMW-KM645 Measurement Control Commands Manual operation: "AF > AF Filter" on page 24 CONFigure:FMSTereo:MEAS<i>:MEValuation:AF:FILTer:WEIGhting <Filter> Selects the weighting filter for the AF analyzer input path. Parameters: <Filter> OFF | AWEight OFF: Bypass weighting filter stage (filter off)
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® Command Reference R&S CMW-KM645 Measurement Control Commands Example: Continuous and AF Measurements Firmware/Software: V1.0.15.20 Manual operation: "AF > Bandpass Variable" on page 24 CONFigure:FMSTereo:MEAS<i>:MEValuation:RESult:RFSCalars <Enable> CONFigure:FMSTereo:MEAS<i>:MEValuation:RESult:AFSCalars <Enable> Enables or disables the evaluation of results and shows or hides the views in the "FM Stereo Radio"...
® Command Reference R&S CMW-KM645 Measurement Results <BandRmsEnable> OFF | ON Disable/enable limit check for frequency deviation after band- pass, RMS value *RST: <THDpercEnable> OFF | ON Disable/enable limit check for Total Harmonic Distortion *RST: <THDNEnab> OFF | ON Disable/enable limit check for Total Harmonic Distortion and...
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® Command Reference R&S CMW-KM645 Measurement Results The number to the left of each result parameter is provided for easy identification of the parameter position within the result array. Return values: <1_Reliability> Reliability Indicator <2_OutOfTol> Out of tolerance result, i.e. percentage of measurement intervals in the statistics cycle (CONFigure:FMSTereo:MEAS<i>:...
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® Command Reference R&S CMW-KM645 Measurement Results Return values: <Reliability> Reliability Indicator <OutOfTol> Out of tolerance result, i.e. percentage of measurement intervals in the statistics cycle (CONFigure:FMSTereo:MEAS<i>: on page 43) exceeding MEValuation:SCOunt:RFCarrier the specified limits, see Limit Settings. Range: 0 % to 100 % Default unit: % <CarrierPower>...
® Command Reference R&S CMW-KM645 Measurement Results <5_AudioRightDev> Standard deviation of the audio right deviation, ±Peak / 2 Range: 0 Hz to +48 kHz Default unit: Hz <6_PilotFreqErr> Standard deviation of the pilot frequency error Range: 0 Hz to +1500 Hz Default unit: Hz <7_RDS_Dev>...
® Command Reference R&S CMW-KM645 Measurement Results READ:FMSTereo:MEAS<i>:MEValuation:AFLeft:AVERage? READ:FMSTereo:MEAS<i>:MEValuation:AFLeft:MAXimum? CALCulate:FMSTereo:MEAS<i>:MEValuation:AFLeft:CURRent? CALCulate:FMSTereo:MEAS<i>:MEValuation:AFLeft:AVERage? CALCulate:FMSTereo:MEAS<i>:MEValuation:AFLeft:MAXimum? Returns the "AF Results" for the left audio channel. The MAXimum results correspond to the "Max/Ext" results of the GUI. The values described below are returned by FETCh and READ commands. CALCulate commands return limit check results instead, one value for each result listed below.
® Command Reference R&S CMW-KM645 Measurement Results <7_THDN> Standard deviation of the total harmonic distortion and noise in percent Range: 0 % to 50 % Default unit: % <8_SINAD> Standard deviation of the signal to noise and distortion ratio Range:...
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® Command Reference R&S CMW-KM645 Measurement Results <2_OutOfTol> Out of tolerance result, i.e. percentage of measurement intervals in the statistics cycle (CONFigure:FMSTereo:MEAS<i>: on page 44) exceeding the speci- MEValuation:SCOunt:AF fied limits, see Limit Settings. Range: 0 % to 100 % Default unit: % <3_WeightedRMS>...
® Command Reference R&S CMW-KM645 Measurement Results FETCh:FMSTereo:MEAS<i>:MEValuation:AFRight:SDEViation? READ:FMSTereo:MEAS<i>:MEValuation:AFRight:SDEViation? CALCulate:FMSTereo:MEAS<i>:MEValuation:AFRight:SDEViation? Returns the standard deviation of the "AF Results" for the right audio channel. The values described below are returned by FETCh and READ commands. CALCulate commands return limit check results instead, one value for each result listed below.
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® Command Reference R&S CMW-KM645 Measurement Results <10_CarrierPower> Standard deviation of the carrier power Range: 0 dB to +92.5 dB Default unit: dB <11_AudioRightDev> Standard deviation of the audio right deviation Range: 0 Hz to +48 kHz Default unit: Hz...
® Index R&S CMW-KM645 Index A-Weighting Repetition FM Stereo Radio measurement ........9 FM Stereo Radio measurement ........22 AF Filter results FM Stereo Radio measurement ........24 FM Stereo Radio measurement ........11 Assign Views RF Routing FM Stereo Radio measurement ........24 FM Stereo Radio measurement ........
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