Create a FOM Measurement

All Python examples in this topic create a FOM measurement with the following attributes:

See Also

Python Basics

Learn more about Frequency Offset Mode

See Other SCPI Example Programs

The following Python example will run on any VNA model with FOM (opt S93080A). However, these commands have no provisions for internal second source. It uses Sens:Offset commands.

import pyvisa as visa

# Change this variable to the address of your instrument
VISA_ADDRESS = 'TCPIP0::localhost::inst0::INSTR'

# Create a connection (session) to the instrument
resourceManager = visa.ResourceManager()
session = resourceManager.open_resource(VISA_ADDRESS)

# Command to preset the instrument and deletes the default trace, measurement, and window
session.write("SYST:FPR")

# Create and turn on window 1
session.write("DISP:WIND1:STAT ON")

# Create a measurement with parameter
session.write("CALC1:MEAS1:DEF 'S21'")

# Displays measurement 1 in window 1 and assigns the next available trace number to the measurement
session.write("DISP:MEAS1:FEED 1")

# Set the start and stop frequencies
session.write("SENS1:FREQ:START 1e9")
session.write("SENS1:FREQ:STOP 2e9")

# Set the receivers to be 2e9 -> 3e9
# See SENS:FOM:RNUM? to find the range number for a specific name
session.write("SENS1:FOM:RANG3:FREQ:OFFS 1e9")

# Turns frequency offset on and enable the freq offset settings

session.write("SENS1:FOM ON")

 

The following example can be run ONLY on a VNA with FOM (opt S93080A). It uses the internal 2nd source for the fixed LO frequency.

import pyvisa as visa

# Change this variable to the address of your instrument
VISA_ADDRESS = 'TCPIP0::localhost::inst0::INSTR'

# Create a connection (session) to the instrument
resourceManager = visa.ResourceManager()
session = resourceManager.open_resource(VISA_ADDRESS)

# Command to preset the instrument and deletes the default trace, measurement, and window
session.write("SYST:FPR")

# Create and turn on window 1
session.write("DISP:WIND1:STAT ON")

# Create a measurement with parameter
session.write("CALC1:MEAS1:DEF 'S21'")

# Displays measurement 1 in window 1 and assigns the next available trace number to the measurement
session.write("DISP:MEAS1:FEED 1")
session.write("SENS1:FREQ:START 1e9")
session.write("SENS1:FREQ:STOP 2e9")

# set the receivers to be 2e9 -> 3e9
session.write("SENS1:FOM:RANG3:FREQ:OFFS 1e9")

# setup the 2nd source frequencies
session.write("SENS1:FOM:RANG4:COUP 0")
session.write("SENS1:FOM:RANG4:FREQ:START 1e9")
session.write("SENS1:FOM:RANG4:FREQ:STOP 1e9")

# turn off coupling
session.write("SOUR1:POW:COUP 0")

# set LO power to 10dBm
session.write("SOUR1:POW3 10")

# turn ON port 3, our LO signal
session.write("SOUR1:POW3:MODE ON")
session.write("SENS1:FOM:STAT ON")