Controlling the Siglent SDS1104X-U oscilloscope and SDG1032X Arbitrary Waveform Generator with SCPI. Because of firmware bugs and the resulting inability to download samples directly from the oscilloscope, the scripts use different approaches to obtain the necessary measurements.
Prerequisites:
- SDS1104X-U and SDG1032X connected to the computer with USB cables
pip3 install -U pyvisapip3 install -U matplotlib
Scripts:
SDS1104X-U Limitations and Firmware bugs
The SDS1104X-U omits the bode plot feature of the SDS1104X-E, which has it control an external Siglent AWG to sweep a sine wave across a range of frequencies while measuring the input to and output from a device under test (DUT). At each frequency point, gain and phase are measured and displayed on the plot.
bodeplot.py creates similar functionality for the SDS1104X-U and SDG1032X. To use it:
- Enable channel tracking on the AWG by selecting Utility > CH Copy Coupling > Track ON;
- Connect AWG channel 1 to the input of the DUT;
- Connect AWG channel 2 to DSO channel 1;
- Connect DSO channel 2 to the output of the DUT.
Enter bodeplot.py -amp 10 -a1 1
This has the DSO measure the Vpp of channel 1 and 2 as well as their phase difference while the AWG sweeps a 10 Vpp sine wave from 1 kHz to 100 kHz. It writes the measurements to stdout in CSV format, and plots the results. Because AWG channel 2 is directly connected to DSO channel 1, its probe attenuation is set to 1 in this example. If you do not use channel coupling and use a 10x probe instead, then the -a1 argument can be omitted.
usage: bodeplot.py [-h] [-in inchannel] [-out outchannel] [-awg awgchannel] [-amp amplitude] [-fs startfreq] [-fe endfreq] [-a1 attenuation] [-a2 attenuation] [-q quality]
[-d delay]
Bode Plot
optional arguments:
-h, --help show this help message and exit
-in inchannel DSO channel for AWG output ([1-4], default is 1)
-out outchannel DSO channel for DUT ([1-4], default is 2)
-awg awgchannel AWG output channel ([1,2], default is 1)
-amp amplitude AWG sine wave amplitude in V (default is 1)
-fs startfreq Sweep start frequency in Hz (default is 1000)
-fe endfreq Sweep end frequency in Hz (default is 100000)
-a1 attenuation Probe attenuation factor for inchannel (default is 10)
-a2 attenuation Probe attenuation factor for outchannel (default is 10)
-q quality Output quality ([1-10], default is 1)
-d delay Delay between measurements in seconds (default is 0)
Creates Bode Plot and CSV output using SDS1104X-U and DSG1032X.
The -d argument is useful if Average acquisition mode is used, to have it settle down for a few seconds before the Vpp and phase is measured.
Samples the currently displayed signal of the active DSO channels, optionally controlling the AWG by enabling a sine wave on one channel and stepping through a series of DC voltages on another channel. Without arguments, this script produces a snapshot of the current trace.
Curve Tracer
optional arguments:
-h, --help show this help message and exit
-awg awgchannel AWG sine wave output channel ([1,2])
-amp amplitude Sine wave amplitude in V (default is 2)
-o offset Sine wave offset in V (default is 0)
-f freq Sine wave frequency in Hz (default is 1000)
-dcawg awgchannel AWG DC output channel ([1,2])
-vmin vmin AWG minimum DC voltage (default is 0)
-vmax vmax AWG maximum DC voltage (default is 2)
-n steps Number of DC steps (default is 5)
-q quality Output quality ([1-10], default is 1)
Samples signal of active DSO channels, optionally enabling a sine wave and stepping through a series of DC voltages with the AWG.
Samples active oscilloscope channels in Roll mode at the trigger point. Outputs each sample's timestamp, elapsed time, and voltage of the active channels to stdout in CSV format. Optionally plots the output. It is assumed that each channel is set up with the optimal vertical scale and position. Can also be used in combination with the AWG by having it step through a range of voltages before each sample. In this mode it should be used with a timebase of at most 1ms per division, not in Roll mode.
usage: datalogger.py [-h] [-i interval] [-n limit] [-p] [-awg awgchannel] [-vmin vmin] [-vmax vmax]
Data Logger
optional arguments:
-h, --help show this help message and exit
-i interval Sample interval in seconds (default is 1)
-n limit Maximum number of samples (default is unlimited)
-p Plot samples (only available with sample limit)
-awg awgchannel AWG output channel ([1,2], AWG off by default)
-vmin vmin AWG minimum DC voltage (default is 0)
-vmax vmax AWG maximum DC voltage (default is 1)
Output timestamp, elapsed time, and voltage of active scope channels at trigger point with SDS1104X-U. Optionally change SDG1032X DC voltage before taking each sample.
Optimizes the vertical offset and scale of active SDS1104X-U scope channels. Assumes that the minimum and maximum values of the signals each fit within the screen limits before the script is executed.
usage: autoscale.py [-h] [-d vdiv] [-i iterations]
Autoscale
optional arguments:
-h, --help show this help message and exit
-d vdiv Vertical divisions (default is 7.5)
-i iterations Number of iterations (default is 2)
Optimizes vertical offset and scale of active scope channels.
This script is an ideal candidate for assigning a keyboard shortcut. On my Mac, I created a Shell Script shortcut with the Shortcuts application:
DIR=~/Projects/eelab
$DIR/autoscale.py
I then added it to the menu bar, and assigned the Control-Option-Command-A keyboard shortcut to it.
SCPI utility for SDS1104X-U and DSG1032X.
For example, ./scpi.py dso -q "C1:PAVA? PKPK" or ./scpi.py dso -q "C1-C2:MEAD? PHA" -x.
usage: scpi.py [-h] [-q query] [-c command] [-x] target
SCPI Utility
positional arguments:
target Target instrument (one of 'dso' or 'awg')
optional arguments:
-h, --help show this help message and exit
-q query SCPI query
-c command SCPI command
-x Output query result as byte array
Submit SCPI command or query to SDS1104X-U or DSG1032X.