Rohde & Schwarz Instruments

How to control R&S spectrum analyzers, signal generators, and oscilloscopes with PyVISA. Connection snippets, examples, and vendor quirks.

Control Rohde & Schwarz spectrum analyzers, signal generators, and oscilloscopes with PyVISA. One connect snippet, one example per instrument type.

Supported Models

Family	Models	Interface
Spectrum analyzers	FSW (8/26/43/67/85), FSV3000/4000, FPS, FSVA	LAN, USB, GPIB
Signal generators	SMW200A, SMB100A/B, SMBV100A/B, SGT100A	LAN, USB, GPIB
Oscilloscopes	RTO2000/6000, RTB2000, RTM3000	LAN, USB
Network analyzers	ZNA, ZNB, ZNC series	LAN, USB, GPIB

Connect to an R&S Instrument

R&S instruments use USB vendor ID 0x0AAD. Most R&S instruments support HiSLIP over LAN (port 4880), which is faster than VXI-11.

import pyvisa

rm = pyvisa.ResourceManager()

# USB
inst = rm.open_resource("USB0::0x0AAD::0x0054::123456::INSTR")

# HiSLIP over LAN (preferred for R&S)
inst = rm.open_resource("TCPIP::192.168.1.100::hislip0::INSTR")

# VXI-11 (fallback)
inst = rm.open_resource("TCPIP::192.168.1.100::inst0::INSTR")

inst.timeout = 30000  # R&S instruments can be slow on first command
print(inst.query("*IDN?").strip())

Log measurements automatically

TofuPilot records spectrum and signal measurements from your R&S instruments, tracks pass/fail rates, and generates compliance reports. Free to start.

Spectrum Analyzer (FSW / FSV)

Configure a span, run a single sweep, and find the peak.

import pyvisa
import numpy as np

rm = pyvisa.ResourceManager()
fsa = rm.open_resource("TCPIP::192.168.1.100::hislip0::INSTR")
fsa.timeout = 30000

fsa.write("*RST")
fsa.write("*CLS")
fsa.write("INIT:CONT OFF")            # Single sweep mode

# Configure span
fsa.write("FREQ:CENT 1E9")            # 1 GHz center
fsa.write("FREQ:SPAN 100E6")          # 100 MHz span
fsa.write("BAND:RES 1E6")             # 1 MHz RBW
fsa.write("BAND:VID:AUTO ON")
fsa.write("DISP:WIND:TRAC:Y:RLEV 0") # 0 dBm reference level
fsa.write("INP:ATT 10")               # 10 dB attenuation

# Single sweep
fsa.write("INIT:IMM")
fsa.query("*OPC?")

# Read trace
trace = fsa.query_ascii_values("TRAC1? TRACE1")
freqs = np.linspace(0.95e9, 1.05e9, len(trace))

# Peak search
fsa.write("CALC:MARK:MAX")
peak_freq = float(fsa.query("CALC:MARK:X?"))
peak_level = float(fsa.query("CALC:MARK:Y?"))
print(f"Peak: {peak_freq/1e6:.2f} MHz at {peak_level:.1f} dBm")

fsa.close()
rm.close()

Signal Generator (SMW / SMB)

Set a CW tone with AM modulation.

import pyvisa

rm = pyvisa.ResourceManager()
smb = rm.open_resource("TCPIP::192.168.1.101::hislip0::INSTR")
smb.timeout = 10000

smb.write("*RST")
smb.write("*CLS")

# CW signal: 2.4 GHz, -10 dBm
smb.write("SOUR:FREQ 2.4E9")
smb.write("SOUR:POW -10")
smb.write("OUTP:STAT ON")

# Add AM modulation
smb.write("SOUR:AM:STAT ON")
smb.write("SOUR:AM:SOUR INT")
smb.write("SOUR:AM:INT:FREQ 1000")    # 1 kHz modulation
smb.write("SOUR:AM:DEPT 50")          # 50% depth

print("Output: 2.4 GHz, -10 dBm, AM 1 kHz 50%")

# smb.write("OUTP:STAT OFF")
# smb.close()
# rm.close()

Oscilloscope (RTO / RTB)

Capture a waveform and read automated measurements.

import pyvisa
import numpy as np

rm = pyvisa.ResourceManager()
rto = rm.open_resource("TCPIP::192.168.1.102::hislip0::INSTR")
rto.timeout = 30000

rto.write("*RST")
rto.write("FORM:DATA REAL,32")
rto.write("FORM:BORD NORM")

# Channel setup
rto.write("CHAN1:STAT ON")
rto.write("CHAN1:COUP DC")
rto.write("CHAN1:SCAL 0.5")           # 500 mV/div
rto.write("TIM:SCAL 1E-6")           # 1 us/div

# Trigger
rto.write("TRIG:SOUR CHAN1")
rto.write("TRIG:LEV 0.1")
rto.write("TRIG:SLOP POS")
rto.write("TRIG:MODE NORM")

# Acquire
rto.write("SING")
rto.query("*OPC?")

# Read waveform
waveform = rto.query_binary_values("CHAN1:DATA?", datatype='f')
print(f"Acquired {len(waveform)} points")

# Automated measurements
freq = float(rto.query("MEAS:FREQ? CHAN1"))
ampl = float(rto.query("MEAS:AMPL? CHAN1"))
print(f"Frequency: {freq:.1f} Hz, Amplitude: {ampl:.3f} V")

rto.close()
rm.close()

R&S Quirks

Quirk	Details	Workaround
HiSLIP preferred	VXI-11 works but HiSLIP is faster and more reliable	Use `hislip0` in the resource string
Slow first command	First SCPI command after connect can take several seconds	Set `timeout = 30000` at connection time
Verbose errors available	`SYST:ERR:VERB ON` gives human-readable error messages	Enable after `*RST` for easier debugging
Status byte format	R&S error strings use `0,"No error"` (not `+0`)	Match both `0,` and `+0,` when draining error queue
Spectrum analyzer sweep time	Complex measurements (EMI, phase noise) can run for minutes	Set timeout per measurement, not globally
Oscilloscope data format	Must set `FORM:DATA` and `FORM:BORD` before reading waveforms	Always configure after `*RST`
Probe auto-detection	`CHAN:PROB:AUTO ONCE` exists on RTO but not RTB	Wrap in try/except
Long calibration	Internal calibration (`*CAL?`) can take 60+ seconds	`inst.timeout = 120000` before calling