FAQs from Rohde & Schwarz

RTH Python Example - Transfer waveform data + screenshot

Question

This Python example shows how to transfer waveform data (ASCII and binary format) + screenshot from RTH oscilloscope to the controller PC. The RTH probe compensation signal can be used for simple test.

ASCI waveform binary waveform
Transfer waveform data screenshot

Answer

"""

This Python example shows how to transfer waveform data (ASCII and binary format) + screenshot from RTH oscilloscope to the controller PC. The RTH probe compensation signal can be used for a simple test.

Preconditions:
- Installed RsInstrument Python module Version 1.5.0 or newer from pypi.org
- Installed VISA e.g. R&S Visa 5.12.x or newer

Tested with:
- RTH1002, FW: v1.80.3.4
- Python 3.8.5
- PyVISA 1.11.0
- RsInstrument 1.6.0.32

Author: R&S Customer Support
Updated on 29.09.2020
Version: v1.2

Technical support -> https://www.rohde-schwarz.com/support

Before running, please always check this script for unsuitable setting ! This example does not claim to be complete. All information have been compiled with care. However, errors can’t be ruled out.

"""

from RsInstrument.RsInstrument import RsInstrument, BinIntFormat
import matplotlib.pyplot as plt
from time import time

def main():
rth = None
try:
# adjust the VISA Resource string to fit your instrument
rth = RsInstrument('TCPIP::192.168.0.1::INSTR', True, False)
# rth = RsInstrument('USB0::0x0AAD::0x012F::1317.5000K02/103176::INSTR', True, False)
rth.visa_timeout = 6000 # Timeout for VISA Read Operations
rth.opc_timeout = 3000 # Timeout for opc-synchronised operations
rth.instrument_status_checking = True # Error check after each command
except Exception as ex:
print('Error initializing the instrument session:\n' + ex.args[0])
exit()

print(f'Device IDN: {rth.idn_string}')
print(f'Device Options: {",".join(rth.instrument_options)}\n')

rth.clear_status()
rth.reset()

# basic settings - to test with RTH probe compensation signal
rth.write_str("TIM:SCAL 0.001")
rth.write_str("ACQ:WAV FULL") # relevant if time scale is ≥50 ms/div
rth.write_str("CHAN1:SCAL 0.02")
rth.write_str("CHAN1:POS -2.5")
rth.write_str("TRIG:LEV1:VAL 0.05")

rth.write_str("TRIG:MODE SING")
start = time()
rth.write_str_with_opc("RUN")
stop = time()
print('RTH triggered, capturing data ...')
print(f'Number of sample points: {rth.query_float("ACQ:POIN?")}')
print(f'Data capturing elapsed time: {stop - start:.3f}sec')

# get binary data
start = time()
rth.write_str("FORMat:DATA INT,16")
rth.bin_int_numbers_format = BinIntFormat.Integer16_2bytes
rth.data_chunk_size = 100000 # transfer in blocks of 100k bytes (default)
data_bin = rth.query_bin_or_ascii_int_list("CHAN:DATA?")

ch1_scale = rth.query_float("CHAN1:SCAL?")

ch1_offs = rth.query_float("CHAN1:OFFS?")

ch1_pos = rth.query_float("CHAN1:POS?")

# see RTH manual for details -> Transfer of Waveform Data
factor = ch1_scale * 8 / (255*256)
offs = ch1_offs - ch1_pos * ch1_scale
# apply multiplication factor and offset to the raw ADC values
data_bin = [(x * factor + offs) for x in data_bin]

print(f'Binary waveform transfer elapsed time: {time() - start:.3f}sec')

plt.figure(1)
plt.plot(data_bin)
plt.title('Binary waveform')

# get ASCII data
start = time()
rth.write_str("FORM:DATA ASC")
rth.data_chunk_size = 100000 # transfer in blocks of 100k bytes (default)
data_asc = rth.query_bin_or_ascii_float_list("CHAN:DATA?")

print(f'ASCII waveform transfer elapsed time: {time() - start:.3f}sec')

plt.figure(2)
plt.plot(data_asc)
plt.title('ASCII waveform')

# get screenshot
file_path_instr = r'/media/SD/Rohde-Schwarz/RTH/Screenshots/Device_Screenshot.png'
file_path_pc = r'c:\temp\Device_Screenshot.png'

rth.write_str("HCOP:LANG PNG")
rth.write_str(f"MMEM:NAME '{file_path_instr}'")
rth.write_str_with_opc("HCOP:IMM")
rth.read_file_from_instrument_to_pc(file_path_instr, file_path_pc)

rth.close()
plt.show()

if __name__ == "__main__":
main()

Name
Type
Version
Date
Size
RTH pyhton example
Type
FAQ
Version
01.20
Date
12-Oct-2020
Size
4 kB