Instrument (MXG/EXG Real-Time Software)

This topic describes the parameters available in the ClosedInstrument node for real-time Signal Studio products. Some parameters will vary by product.

State On

State Off

Update from Instrument

Preset

DC Cal

Power Search

Hint

1. Configuration

2. Basic

3. I/Q

4. ALC

5. Baseband

6. AUX IO Global Controls

7. Trigger

8. Real-time AWGN Setup

State On

Turns the application on, generating the real-time IQ signal in the connected instrument with the parameters you set in the software.

[:SOURce]:RADio:WCDMa:TGPP[:BBG][:STATe] ON|OFF|1|0

[:SOURce]:RADio:WCDMa:TGPP[:BBG][:STATe]?

State Off

Turns the application off, disabling the real-time IQ and RF signals on the connected instrument.

[:SOURce]:RADio:WCDMa:TGPP[:BBG][:STATe] ON|OFF|1|0

[:SOURce]:RADio:WCDMa:TGPP[:BBG][:STATe]?

Update from Instrument

Retrieves the parameters from the connected instrument and updates the Instrument node settings.

Preset

Sets the signal generator to the factory-defined default state.

:SYSTem:PRESet

*RST

DC Cal

Performs a one to two second adjustment that is not traceable to a standard. However, it will minimize errors associated with offset voltages. This adjustment minimizes errors for the current instrument setting and at a single frequency. The DC adjustment is volatile and must be repeated with each instrument setting change.

:CALibration:IQ:DC

*OPC

Power Search

Coupling:The ALC must be Off to use this feature.

Executes a manual power search calibration. This is an internal calibration routine that improves output power accuracy when the ALC is turned off. A power search is recommended for pulse-modulated signals with pulse-widths less than two microseconds.

[:SOURce]:POWer:ALC:SEARch ONCE

*OPC

Hint

Select the Hint checkbox then click a parameter cell to display a brief description of the parameter.

1. Configuration

Instrument Model Number

When active, you can manually select an instrument model number. If Retrieve Instrument Model Number is set to Auto, the model number of the connected instrument appears here after you run the System Configuration Wizard. The parameters that are available in the Instrument node are determined by the Instrument Model Number.

2. Basic

Frequency

Range: for frequency range values, see the signal generator's data sheet

Enter a value to set the signal generator’s output frequency. Use abbreviations for faster entry (example: 1g = 1.000000000000 GHz).

[:SOURce]:FREQuency[:CW] <val><unit>

[:SOURce]:FREQuency[:CW]?

Amplitude

Range: for amplitude range values, see the signal generator's data sheet

Enter a value to set the signal generator’s output amplitude in dBm.

[:SOURce]:POWer[:LEVel][:IMMediate][:AMPLitude] <val><unit>

[:SOURce]:POWer[:LEVel][:IMMediate][:AMPLitude]?

RF Output

Double-click or use the drop-down menu to turn the signal generator’s RF output On or Off.

:OUTPut[:STATe] ON|OFF|1|0

:OUTPut[:STATe]?

3. I/Q

I/Q Adjustments

Choice: Off | On

Default: Off

Double-click or use the drop-down menu to turn the I/Q adjustments On or Off.

On – The values entered for I Offset, Q Offset, and so on are applied to the I and Q signals.

Off – I/Q adjustment values are not applied to the I and Q signals.

[:SOURce]:DM:IQADjustment[:STATe] ON|OFF|1|0

[:SOURce]:DM:IQADjustment[:STATe]?

I Offset

Range: –20% to 20%

Default: 0.00%

Enter a DC offset value to apply to the I signal before the I/Q modulator. Use this offset to remove imperfections in the in-phase signal or to introduce calibrated impairments.

When using this setting to minimize the LO feed-through signal, optimum performance is achieved when the adjustment is made after any other I/Q path adjustments. If other adjustments are made after minimization is performed, the LO feed-through signal may increase.

Set I/Q Adjustments to On to enable this parameter.

[:SOURce]:DM:IQADjustment:IOFFset <val><unit>

[:SOURce]:DM:IQADjustment:IOFFset?

Q Offset

Range: –20% to 20%

Default: 0.00%

Enter a DC offset value to apply to the Q signal before the I/Q modulator. Use this offset to remove imperfections in the quadrature-phase signal or to introduce calibrated impairments.

When using this setting to minimize the LO feed-through signal, optimum performance is achieved when the adjustment is made after any other I/Q path adjustments. If other adjustments are made after minimization is performed, the LO feed-through signal may increase.

Set I/Q Adjustments to On to enable this parameter.

[:SOURce]:DM:IQADjustment:QOFFset <val><unit>

[:SOURce]:DM:IQADjustment:QOFFset?

I/Q Gain Balance

Range: –1 dB to 1 dB

Default: 0.000 dB

Enter a value to set the gain for the I signal relative to the Q signal.

Example: If you enter a value of 1 dB, the I signal will have 1 dB more amplitude than the Q signal.

Set I/Q Adjustments to On to enable this parameter.

[:SOURce]:DM:IQADjustment:GAIN[1] <val><unit>

[:SOURce]:DM:IQADjustment:GAIN[1]?

Quadrature Angle Adjustment

Range: –10 to 10 degrees

Default: 0.00 degrees

Enter a value to adjust the Q phase angle. When the quadrature skew is zero, the phase angle between the I and Q vectors is 90 degrees. Positive skew increases the angle from 90 degrees; negative skew decreases the angle from 90 degrees.

Set I/Q Adjustments to On to enable this parameter.

[:SOURce]:DM:IQADjustment:QSKew <val><unit>

[:SOURce]:DM:IQADjustment:QSKew?

I/Q Timing Skew Path

This cell is grayed out and provides no function.

I/Q Correction Optimized Path

Choice: RF Output | Ext I/Q Output

Default: RF Output

RF Output optimizes the RF OUT path by applying calibration factors to only this path, leaving the I/Q OUT path uncalibrated.

Note: With External as the I/Q Source selection, the signal generator automatically optimizes both paths, so no optimization path selection is needed.

Ext I/Q Output optimizes the I/Q OUT path by applying calibration factors to only this path, leaving the RF OUT path uncalibrated.

Note: With External as the I/Q Source selection, the signal generator automatically optimizes both paths, so no optimization path selection is needed.

This parameter is not available for all instrument model numbers and may be grayed out.

[:SOURce]:DM:CORRection:OPTimization RFOut|EXTernal

[:SOURce]:DM:CORRection:OPTimization?

I/Q Skew

Range: –500 ns to 500 ns

Default: 0.0 seconds

Enter a value to set the time delay between I and Q.

A positive value delays the I signal relative to the Q signal.

A negative value delays the Q signal relative to the I signal.

[:SOURce]:DM:IQADjustment:SKEW <val><unit>

[:SOURce]:DM:IQADjustment:SKEW?

I/Q Delay

Range: –250 ns to 250 ns

Default: 0.0 seconds

Enter a value to change the absolute phase of both I and Q with respect to triggers and markers. A positive value delays I and Q. This value affects both the external I/Q out signals and the baseband signal modulated on the RF output. This adjustment cannot be used with constant envelope modulation and does not affect external I/Q inputs.

The limits are determined by the rate of the current format.

[:SOURce]:DM:IQADjustment:DELay <val><unit>

[:SOURce]:DM:IQADjustment:DELay?

4. ALC

ALC

Choice: Off | On

Default: On

Double-click or use the drop-down menu to enable or disable the automatic level control.

On – The ALC circuit constantly monitors and controls the output power level.

Off – No automatic leveling occurs.

[:SOURce]:POWer:ALC[:STATe] ON|OFF|1|0

[:SOURce]:POWer:ALC[:STATe]?

ALC Bandwidth

Choice: Auto | 200 Hz | 2 kHz | 20 kHz

Default: Auto

Double-click or use the drop-down menu to select an ALC bandwidth.

This parameter is not available for all instrument model numbers and may be grayed out.

[:SOURce]:POWer:ALC:BANDwidth|BWIDth:AUTO ON|OFF|1|0

[:SOURce]:POWer:ALC:BANDwidth|BWIDth:AUTO?

[:SOURce]:POWer:ALC:BANDwidth|BWIDth 200Hz|2kHz|20kHz

[:SOURce]:POWer:ALC:BANDwidth|BWIDth?

Power Search Reference

Choice: Fixed | Modulation | RMS

Default: Modulation

Double-click or use the drop-down menu to select one of the following reference signals when doing a power search.

Fixed – Power search uses a fixed 0.5 V reference.

Modulation – Power search uses the AC bias from the actual modulating signal.

RMS – Power search uses a DC bias value equivalent to the value derived from the file header or the calculated value from the current I/Q data.

Set ALC to Off to enable this parameter.

[:SOURce]:POWer:ALC:SEARch:REFerence RMS|FIXed|MANual|MODulated

[:SOURce]:POWer:ALC:SEARch:REFerence?

RF During Power Search

Choice: Normal | Minimum

Default: Normal

Double-click or use the drop-down menu to select the level of the output power control during a power search routine.

Normal – Performs power searches without setting the internal step attenuator to its maximum setting. Glitches and power changes may be present during the search.

Minimum – Sets the signal generator's step attenuator to its maximum setting during power search to protect sensitive circuits.

Set ALC to Off to enable this parameter.

[:SOURce]:POWer:PROTection[:STATe] ON|OFF|1|0

[:SOURce]:POWer:PROTection[:STATe]?

5. Baseband

Sample Rate

Range: dependent on the instrument and its configuration—refer to the instrument's Data Sheet for the range

Default: 3.840000 MSa/s

Modify the Sample Rate by entering a value within the limits of the instrument.

[:SOURce]:RADio:WCDMa:TGPP[:BBG]:SAMPle:RATE <val>

[:SOURce]:RADio:WCDMa:TGPP[:BBG]:SAMPle:RATE?

Runtime Scaling

Range: -60.00 to 0.00 dB

Default: 0.00 dB

Adjusts the scaling of the I and Q data. Reducing the runtime scaling prevents over ranges from occurring. Runtime scaling is also used to scale signals relative to each other.

[:SOURce]:RADio:WCDMa:TGPP[:BBG]:RSCaling <val>

[:SOURce]:RADio:WCDMa:TGPP[:BBG]:RSCaling?

Frequency Offset

Range: -60 MHz to 60 MHz

Default: 0 Hz

Moves the baseband signal above or below the carrier by the specified frequency. When simulating adjacent channel interferers, this allows you to offset the waveforms to avoid overlap between the waveforms.

[:SOURce]:RADio:WCDMa:TGPP[:BBG]:FREQuency:OFFSet <val>

[:SOURce]:RADio:WCDMa:TGPP[:BBG]:FREQuency:OFFSet?

Input RMS Source

Identifies where the instrument gets the RMS voltage value of the signal to ensure the correct amplitude of the signal is at the output of the signal generator when the power calibration is performed.

[:SOURce]:RADio:WCDMa:TGPP[:BBG]:POWer:SOURce

[:SOURce]:RADio:GNSS[:BBG]:POWer:PMGating

[:SOURce]:RADio:GNSSPRO[:BBG]:POWer:PMGating

[:SOURce]:RADio:GNSS[:BBG]:POWer:SAVerage

[:SOURce]:RADio:GNSSPRO[:BBG]:POWer:SAVerage

[:SOURce]:RADio:GNSS[:BBG]:POWer:THReshold

[:SOURce]:RADio:GNSSPRO[:BBG]:POWer:THReshold

[:SOURce]:RADio:GNSS[:BBG]:POWer:HCOunt

[:SOURce]:RADio:GNSSPRO[:BBG]:POWer:HCOunt

6. AUX IO Global Controls

Operating Mode

Choice: Multiplexed | Dedicated

Default: Multiplexed

Double-click or use the drop-down menu to select the AUX I/O port operating mode.

Multiplexed − configures the AUX I/O port operating mode to Multiplexed for real-time applications.

Dedicated − configures the AUX I/O port operating mode to Dedicated for real-time applications.

[:SOURce]:IQ:AUX:OPERating:MODE DEDicated|MULTiplexed

[:SOURce]:IQ:AUX:OPERating:MODE?

Input Strobe

Choice: Free Run | User

Default: Free Run

Double-click or use the drop-down menu to select the AUX I/O port input strobe. In Dedicated operating mode, the instrument will always be in Free Run mode. If Multiplexed mode is selected, either Free Run or User input strobe mode can be selected.

Free Run − new input data is latched based on an internal clock.

User − a user supplied strobe signal is used to latch data.

[:SOURce]:IQ:AUX:INPut:STRobe[:MODE] FREE|USER

[:SOURce]:IQ:AUX:INPut:STRobe[:MODE]?

Input Strobe Polarity

Choice: Positive | Negative

Default: Positive

Double-click or use the drop-down menu to select the polarity of the user external input strobe signal. This external input strobe signal must be at least 200 ns wide, and user must hold assert 16 input data bits stable 20 ns before the active edge of the user input strobe and hold the data stable for at least 100 ns after the active edge of the user input strobe.

Positive − a rising edge of the external strobe signal will latch the data.

Negative − a falling edge will latch the data.

[:SOURce]:IQ:AUX:INPut:STRobe:SLOPe POSitive|NEGative

[:SOURce]:IQ:AUX:INPut:STRobe:SLOPe?

Output Strobe Polarity

Choice: Positive | Negative

Default: Positive

Double-click or use the drop-down menu to select the polarity of the AUX output sample clock. This signal indicates that the 16 input data bits have been latched and will be output in both Free Run and external input strobe mode. The output pulse will be at least 200 ns wide.

Positive − a pulse with a rising edge will be asserted to indicate when the 16 input data bits have been latched.

Negative − a pulse with a falling edge will be asserted to indicate when the 16 input data bits have been latched.

[:SOURce]:IQ:AUX:OUTPut:STRobe:SLOPe POSitive|NEGative

[:SOURce]:IQ:AUX:OUTPut:STRobe:SLOPe?

7. Trigger

Trigger Type

Choice: Free Run | Trigger & Run

Default: Free Run

Coupling: In multiple-instrument configurations, the Trigger Type is set to Trigger and Run for all and cannot be changed

Double-click or use the drop-down menu to select the continuous mode and one of the following trigger responses.

Free Run − immediately triggers when you turn the format on.

Trigger & Run − waits for and starts on the first trigger; ignores subsequent triggers.

[:SOURce]:IQ:OUTPut:TRIGger:CONTinuous[:TYPE] FREE|TRIGger

[:SOURce]:IQ:OUTPut:TRIGger:CONTinuous[:TYPE]?

Trigger Source

Choice: Trigger Key | External | Bus

Default: External

Coupling: In multiple-instrument configurations, this parameter can only be changed on Instrument 1.

Adjusts the trigger source applied to the PATT TRIG IN or AUX I/O connectors.

Trigger Key − selects the front panel hardkey as the trigger source. After making this selection, press the Trigger hardkey to trigger a waveform.

External − enables you to trigger a waveform with an externally supplied trigger signal.

Bus − enables you to trigger a waveform by sending a command through the GPIB, LAN, or AUXILIARY IO (RS-232) input connector.

[:SOURce]:IQ:OUTPut:TRIGger:SOURce KEY|BUS|EXTernal

[:SOURce]:IQ:OUTPut:TRIGger:SOURce?

External Source

Choice: Pattern Trigger In 1 | Pattern Trigger In 2

Default: Pattern Trigger In 1

Selects the rear-panel connector for the external trigger source. This parameter is enabled only if external triggering is selected as the trigger source.

Pattern Trigger In 1 − selects the PATTERN TRIG IN rear-panel BNC connector

Pattern Trigger In 2 − selects the PATTERN TRIG IN 2 (AUXILIARY I/O) rear panel connector

[:SOURce]:IQ:OUTPut:TRIGger:EXTernal:SOURce EPT1|EPT2|EPTRIGGER1|EPTRIGGER2

[:SOURce]:IQ:OUTPut:TRIGger:EXTernal:SOURce?

External Polarity

Choice: Positive | Negative

Default: Negative

Sets the polarity of the external trigger. This parameter is active only if you select external (Ext) as the trigger source.

Positive − the signal generator triggers an event when it detects a rising edge on the PAT TRIG IN signal.

Negative − the signal generator triggers an event when it detects a falling edge on the PAT TRIG IN signal.

[:SOURce]:IQ:OUTPut:TRIGger:EXTernal:POLarity POSitive|NEGative

[:SOURce]:IQ:OUTPut:TRIGger:EXTernal:POLarity?

External Delay Time

Range: 0 s to 41 s

Default: 0 s

Enter a value to set a delay time between when an external trigger is received and when it is applied to the signal.

[:SOURce]:IQ:OUTPut:TRIGger:EXTernal:DELay <val>

[:SOURce]:IQ:OUTPut:TRIGger:EXTernal:DELay?

8. Real-time AWGN Setup

Real-time AWGN

Choice: On | Off

Default: Off

Double-click or use the drop-down menu to enable or disable the AWGN generator.

On − enables the AWGN.

Off − disables the AWGN.

[:SOURce]:IQ:OUTPut:IMPairments:AWGN[:STATe] ON|OFF|1|0

[:SOURce]:IQ:OUTPut:IMPairments:AWGN[:STATe]?

Signal to Noise Ratio

Range: –100 dB to 100 dB

Default: 0 dB

Enter a value to set the signal to noise ratio.

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:SNR <val>

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:SNR?

Integration Bandwidth

Choice: Auto | Manual

Default: Auto

Specifies the integration bandwidth is auto or manual.

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:IBWidth:AUTO ON|OFF|1|0

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:IBWidth:AUTO?

Integration Bandwidth

Range: 1.0 Hz to 200.000 MHz, the limits are affected by the instrument types and options.

Default: 3.840000 MHz

Specifies the bandwidth over which the noise power is integrated for calculating the carrier to noise ratio.

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:IBWidth <val>

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:IBWidth?

Flat Noise Bandwidth

Range: 1.0 Hz to 160.000 MHz, the limits are affected by the instrument types and options.

Default: 1.0 Hz

Enter a value to set the flat noise bandwidth, which is typically set wider than the carrier bandwidth.

This parameter is not available for all instrument model numbers and may be grayed out.

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:BANDwidth|BWIDth <val>

[:SOURce]:IQ:OUTPut:IMPairments:AWGN:BANDwidth|BWIDth?