ML2439A USB Power Meter User Guide : SCPI Commands : CALCulate Subsystem
 
CALCulate Subsystem
Functions in the CALCulate subsystem are used to configure the measurement mode and control which portions of the acquired measurement data is used and how it is processed to yield a finished measurement. In addition to measurement mode, CALCulate is used to define mathematical operations, and measurement units. The numeric suffix of the CALCulate program mnemonic in the CALCulate commands refers to a processing and display “channel”, that is CALCulate1 and CALCulate2 represent the power meter’s Channel 1 and Channel 2 functions. The CALCulate commands generally DO NOT affect the data acquisition portion of the measurement. In a signal-flow block diagram, the CALCulate block operations will follow those of the SENSe block. Note that CALCulate commands will not generate an error if used with a disconnected or non-existing channel on the ML2439A.
CALCulate:DCYCle
Description
Set or return the duty cycle correction factor currently in use on the selected channel.
Syntax:
CALCulate[1|2|3|4]:CORRection:DCYCle <numeric value>
Argument:
<numeric_value> = 0.01 to 100.00 percent Valid Modes: CW Sensor (Modulated Mode)
Modes:
Any
 
CALCulate:MODE
Description
Set or return the system measurement mode. MODULATED mode is a continuous measurement mode primarily for continuously modulated or CW signals. PULSE mode is a signal triggered, oscilloscope-like mode that acquires and analyzes a pulsed signal as a series of one or more triggered sweeps. STATISTICAL mode performs long-term power distribution analysis on modulated signals, and may be operated in a start-stop continuous mode, or a decimated continuous mode.
Note that the measurement mode is global and affects all channels. If any channel has a CW sensor installed, peak or statistical measurements will be unavailable, but the “primary “average power measurement will still be performed.
Syntax:
CALCulate:MODE <character data>
Argument:
<character data> = {MODulated, PULSe, STATistical}
Modes:
Any
 
CALCulate:PKHLD
Description:
Set or return the operating mode of the selected channel’s peak hold function. When set to OFF, instantaneous peaks are only held for a short time, and then decayed towards the average power at a rate proportional to the filter time. This is the best setting for most signals, because the peak will always represent the peak power of the current signal, and the resulting peak-to-average ratio will be correct shortly after any signal level changes. When set to ON, instantaneous peaks are held until reset by a new INITiate command or cleared manually. This setting is used when it is desirable to hold the highest peak over a long measurement interval without any decay.
Syntax:
CALCulate[1|2|3|4]:PKHLD <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, AVG, INST } Valid Modes: Modulated and Pulse Modes
 
CALCulate:STATe
Description:
Set or return the measurement state of the selected channel. When ON, the channel performs measurements; when OFF, the channel is disabled and no measurements are performed.
Syntax:
CALCulate[1|2|3|4]:STATe <Boolean> Argument: <Boolean> = { 0, 1, OFF, ON }
Valid Modes:
Any
 
CALCulate:UNITs
Description:
Set or return units for the selected channel. For power sensors, voltage is calculated with reference to the sensor input impedance. Note that for ratiometric results, logarithmic units will always return dBr (dB relative) while linear units return percent.
Syntax:
CALCulate[1|2|3|4]:UNITs <character data>
Argument:
<character data> = {DBMw, Watts, Volts, DBV, DBMV, DBUV}
Valid Modes:
Any