ML2439A USB Power Meter User Guide : SCPI Commands : READ Queries
 
READ Queries
The purpose of the READ? group of queries is to initiate a measurement cycle, acquire data, and return specific measurement data. READ? performs the initiation, data acquisition, postprocessing, and data output portions of the measurement. READ? is equivalent to ABORting any operation in progress, INITiating a new measurement, then FETChing the data when it is ready. READ? generally does not return data unless acquisition is complete. Since READ? INITiates a new measurement every time it is issued, READ? queries should not be used for free running data acquisition (INITiate:CONTinuous ON) - in this case, use FETCh queries instead. For CW and Modulated Modes, the measurement is generally considered complete when the integration filter (see SENSe:FILTer) is filled. In Pulse Mode, the measurement is considered complete when all the number of complete traces specified by the SENSe:AVERage command have been acquired and averaged together. In Statistical Mode, the measurement is considered complete when the number of samples specified by TRIGger:CDF:COUNt has been gathered.
 
READ:ARRay:AMEAsure:POWer?
Description:
Returns an array of the current automatic amplitude measurements performed on a periodic pulse waveform. Measurements performed are: peak amplitude during the pulse, average amplitude over a full cycle of the pulse waveform, average amplitude during the pulse, IEEE top amplitude, IEEE bottom amplitude, overshoot, and droop. Units are the same as the channel’s units. Note the pulse overshoot is returned in dB for logarithmic channel units, and percent for all other units. Also, the pulse “ON” interval used for peak and average calculations is defined by the SENSe:PULSe:STARTGT and :ENDGT time gating settings. A full pulse (rise and fall) must be visible on the display to make average and peak pulse power measurements, and a full cycle of the waveform must be visible to calculate average cycle amplitude.
Syntax:
READ[1|2|3|4]:ARRay:AMEAsure:POWer?
Returns:
CC1, PulsePeak, CC2, PulseCycleAvg, CC3, PulseOnAvg, CC4, IEEE Top, CC5, IEEE Bot, CC6, Overshoot, CC7, Droop Where the CCn’s are the measurement condition codes for each measurement.
Valid Modes:
Pulse Mode only
Restrictions:
Timebase must be set appropriately to provide measurements (see above)
 
READ:ARRay:AMEAsure:STATistical?
Description:
Returns an array of the current automatic statistical measurements performed on a sample population. Measurements performed are: long term average, peak and minimum amplitude, peak-to-average ratio, amplitude at the CCDF cursor, statistical percent at the CCDF cursor, and the sample population size in samples. Note the peak- to-average ratio is returned in dB for logarithmic channel units, and percent for all other channel units.
Syntax:
READ[1|2|3|4]:ARRay:AMEAsure:STATistical?
Returns:
CC1, Pavg, CC2, Ppeak, CC3, Pmin, CC4, PkToAvgRatio, CC5, CursorPwr, CC6, CursorPct, CC7, Sample-Count Where the CCn’s are the measurement condition codes for each measurement.
Valid Modes:
Statistical Mode only
 
READ:ARRay:AMEAsure:TIMe?
Description:
Returns an array of the current automatic timing measurements performed on a periodic pulse waveform. Measurements performed are: the frequency, period, width, offtime and duty cycle of the pulse waveform, and the risetime and falltime of the edge transitions. For each of the measurements to be performed, the appropriate items to be measured must be visible on the display in GRAPH mode. Pulse frequency, period, offtime and duty cycle measurements require that an entire cycle of the pulse waveform (minimum of three edge transitions) be present. Pulse width measurement requires that at least one full pulse is visible, and is most accurate if the pulse width is at least 0.4 divisions (20 pixels). Risetime and falltime measurements require that the edge being measured is visible, and will be most accurate if the transition takes at least 0.1 divisions (5 pixels). It is always best to have the power meter set on the fastest timebase possible that meets the edge visibility restrictions. Set the trace averaging as high as practical to reduce fluctuations and noise in the pulse timing measurements. Note that the timing of the edge transitions is defined by the settings of the SENSe:PULSe:DISTal, :MESIal and :PROXimal settings; see the descriptions for those commands. Units are the same as the channel’s units.
Syntax:
READ[1|2|3|4]:ARRay:AMEAsure:TIMe?
Returns:
CC1, PulseFreq, CC2, PulsePeriod, CC3, PulseWidth, CC4, Offtime, CC5, DutyCycle, CC6, Risetime, CC7, Falltime, CC8, EdgeDly, CC9, Skew in Hz Where the CCn’s are the measurement condition codes for each measurement.
Valid Modes:
Pulse Mode only.
Restrictions:
Timebase must be set appropriately to provide measurements (see above)
 
READ:ARRay:CW:POWer?
Description:
Returns the current average, maximum, minimum powers or voltages and the peak-to- average ratio of the specified channel. Units are the same as the channel’s units. Note the peak-to-average ratio and marker ratio are returned in dB for logarithmic channel units, and percent for all other channel units.
Note that the values for maximum and minimum power will depend on the peak hold mode; see the description of the CALCulate:PKHLD command for details.
Syntax:
READ[1|2|3|4]:ARRay:CW:POWer?
Returns:
CC1, Pavg, CC2, Pmax, CC3, Pmin, CC4, PkToAvgRatio Where the CCn’s are the measurement condition codes for each measurement.
Valid Modes:
Pulse and Modulated
 
READ:ARRay:MARKer:POWer?
Description:
Returns an array of the current marker measurements for the specified channel. The array consists of the average, maximum, and minimum power and peak-to-average ratio between the two markers, powers at both markers, and the ratio of the two markers.
Note the peak-to-average ratio and marker ratio are returned in dB for log units, and percent for linear units.
Syntax:
READ[1|2|3|4]:ARRay:MARKer:POWer?
Returns:
CC1, Pavg, CC2, Pmax, CC3, Pmin, CC4, PkToAvgRatio, CC5, Pwr@Marker1, CC6, Pwr@Marker2, CC7, Mrk1/Mrk2 ratio Where the CCn’s are the measurement condition codes for each measurement.
Valid Modes:
Pulse and Modulated
 
READ:CW:POWer?
Description:
Return current average amplitude reading in channel units. Syntax: READ[1|2|3|4]:CW:POWer?
Returns:
CC, Average power (watts, dBm) or average voltage (volts, dBv) Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:INTERval:AVERage?
Description:
For the specified channel, return the average power or voltage between marker 1 and marker 2. The units will be the same as the specified channel.
Syntax:
READ[1|2|3|4]:INTERval:AVERage?
Returns:
CC, average power or voltage between markers Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:INTERval:MAXFilt?
Description:
For the specified channel, return the maximum filtered power or voltage in the time interval between marker 1 and marker 2. The units will be the same as the specified channel.
Syntax:
READ[1|2|3|4]:INTERval:MAXFilt?
Returns:
CC, maximum filtered power or voltage between the markers Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:INTERval:MINFilt?
Description:
For the specified channel, return the minimum filtered power or voltage in the time interval between marker 1 and marker 2. The units will be the same as the specified channel.
Syntax:
READ[1|2|3|4]:INTERval:MINFilt?
Returns:
CC, minimum filtered power or voltage between markers Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:INTERval:MAXimum?
Description:
For the specified channel, return the maximum instantaneous power or voltage between marker 1 and marker 2. The units will be the same as the specified channel.
Syntax:
READ[1|2|3|4]:INTERval:AVERage?
Returns:
CC, maximum instantaneous power or voltage between markers Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:INTERval:MINimum?
Description:
For the specified channel, return the minimum instantaneous power or voltage between marker 1 and marker 2. The units will be the same as the specified channel.
Syntax:
READ[1|2|3|4]:INTERval:MINimum?
Returns:
CC, minimum instantaneous power or voltage between markers Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:INTERval:PKAVG?
Description:
For the specified channel, return the peak-to-average ratio of the power or voltage between marker 1 and marker 2. The units are dB for logarithmic channel units or percent for linear channel units.
Syntax:
READ[1|2|3|4]:INTERval:PKAVG?
Returns:
CC, peak-to-average ratio of power or voltage between markers Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:MARKer:AVERage?
Description:
For the specified channel and marker, return the average power or voltage at the marker. The units are the same as the specified channel.
Syntax:
READ[1|2|3|4]:MARKer[1|2]:AVERage?
Returns:
CC, average power or voltage at marker Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated
 
READ:MARKer:DELTa?
Description:
For the specified channel return the difference between MK1 and MK2. The units will be the same as marker units.
Syntax:
READ[1|2|3|4]:MARKer:DELTa?
Returns:
CC, (MK1 – MK2) Where CC is the measurement condition code.
Valid Modes:
All
 
READ:MARKer:MAXimum?
Description:
For the specified channel and marker, return the maximum power or voltage at the marker. The units are the same as the specified channel.
Syntax:
READ[1|2|3|4]:MARKer[1|2]:MAXimum?
Returns:
CC, maximum power or voltage at marker Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated.
 
READ:MARKer:MINimum?
Description:
For the specified channel and marker, return the minimum power or voltage at the marker. The units will be the same as the specified channel.
Syntax:
READ[1|2|3|4]:MARKer[1|2]:MINimum?
Returns:
CC, minimum power or voltage at marker Where CC is the measurement condition code.
Valid Modes:
Pulse and Modulated.
 
READ:MARKer:CURsor:PERcent?
Description:
Return the CCDF cursor y-axis position in percent with respect to the value set by MARKer:POSItion:POWer (CCDF cursor mode is set to Power Ref). If CCDF cursor mode is Percent, returns user setting. See MARKer:POSItion:POWer and MARKer:POSItion:PERcent. Refer to the ML2439A Instruction Manual Statistical Mode Automatic Measurements section for more information.
Syntax:
READ[1|2|3|4]:MARKer:CURsor:PERcent?
Returns:
CC, percent CCDF Where CC is the measurement condition code.
Valid Modes:
Statistical.
 
READ:MARKer:CURsor:POWer?
Description:
Return the CCDF cursor x-axis position in relative power with respect to the value set by MARKer:POSItion:PERcent (CCDF cursor mode is set to Percent). If CCDF cursor mode is Power Ref, returns user setting. See MARKer:POSItion:POWer and MARKer:POSItion:PERcent. Refer to the ML2439A Instruction Manual Statistical Mode Automatic Measurements section for more information.
Syntax:
READ[1|2|3|4]:MARKer:CURsor:POWer?
Returns:
CC, relative power (dBr) CCDF Where CC is the measurement condition code.
Valid Modes:
Statistical
 
READ:MARKer:RATio?
Description:
For the specified channel return the ratio of MK1 to MK2. The units will be dB for logarithmic units or percent for linear units.
Syntax:
READ[1|2|3|4]:Marker:RATio?
Returns:
CC, MK1/MK2 Where CC is the measurement condition code.
Valid Modes:
All
 
READ:MARKer:RDELTa?
Description:
For the specified channel return the difference between MK2 and MK1. The units will be the same as marker units.
Syntax:
READ[1|2|3|4]:MARKer:RDELTa?
Returns:
CC, (MK2-MK1) Where CC is the measurement condition code.
Valid Modes:
All
 
READ:MARKer:RRATio?
Description:
For the specified channel return the ratio of MK2 to MK1. The units will be dB for logarithmic units or percent for linear units..
Syntax:
READ[1|2|3|4]:MARKer:RRATio?
Returns:
CC, MK2/MK1 Where CC is the measurement condition code.
Valid Modes:
All