Binary data formatting often provides the smallest payload size and therefore transfers via USB/LAN more quickly. Unfortunately, binary is very difficult to interpret by humans. So, binary data is often reformatted to other types (ASCII, etc..)/

Here is a link to the binary data format for many popular SIGLENT oscilloscopes:

Extract Binary Data from an SDS oscilloscope

The post How to Extract Data from the Binary File of Siglent Oscilloscope appeared first on Siglent.

Mike Cardoso is a controls engineer working for a leader in the industrial automation sector, primarily focused on motion control and variable frequency drive (VFD) technology. In his free time Mike has a passion for industrial robotics, electrical design and test, and machining and has a home shop for pursuing these activities. Mike purchased a Siglent SDS1204X-E Super Phosphor Oscilloscope for use at home in designing and troubleshooting his projects.

About Siglent and the SDS1000X-E/SDS2000X-E Oscilloscopes

Siglent is known in both the professional and hobby spaces as a manufacturer of well built, intelligently designed, and affordable electrical test and measurement equipment. The SDS1000X-E and SDS2000X-E Super Phosphor Oscilloscopes are well known in the high-end hobby market and professional markets for being one of the most featured oscilloscopes in the price range and the best value one can find. The features available on these oscilloscopes rival those of many large domestic electrical test and measurement manufacturers at a fraction of the price.

About the SLA1016

The SLA1016 is an optional Mixed Signal Oscilloscope (MSO) accessory for the SDS1000X-E and SDS2000X-E oscilloscopes. The SLA1016 consists of a logic module, probe set, and connection cables which allow the user of the scope to add (16) channels of digital measurement in addition to the standard analog channels of the oscilloscope. This allows for the measurement and troubleshooting of more complex digital designs (e.g., parallel data busses, sequential logic, etc.) while maintaining the same timebase as the analog measurements.

The SLA1016 is designed to measure digital logic levels up to 5.0VDC and comes with preconfigured thresholds for TTL, CMOS, LVCMOS3.3, and LVCMOS2.5. The user may also select custom voltage thresholds for their unique needs. The SLA1016 has (2) banks of (8) channels which may be independently configured for the desired voltage threshold. With a sampling rate of 1GSa/s and 1.4Mpts deep memory, the SLA1016 can easily capture high frequency digital signals and save the data for later investigation. Like the analog channels, the SLA1016 will dynamically update the sample rate as the oscilloscope timebase is adjusted to maximize the sample memory of the channels.

The SLA1016 is provided with probes which can attach to standard 0.1” header pins, and included spring loaded clips can optionally be connected for measuring wires or legs of larger integrated circuits.

Features of the SLA1016

The SLA1016 can display digital waveforms on the oscilloscope in banks of either (4), (8), or (16) channels, trading waveform height for additional data on screen. The standard features of the oscilloscope such as cursors, measurements, decode, and triggering can all be used on the digital channels. Additional features specific to the MSO capabilities of the oscilloscope can be found in the
“Digital” menu. These include parallel data bus decoding, deskew control, channel enable, channel height control, and channel positioning on the screen. Channels may be individually enabled/disabled and rearranged in any order desired.

The oscilloscope can be configured to display all channels at the same time (4 analog + 16 digital) in addition to serial bus decoding and 2 parallel bus decoding displays. The screen can become quite full in this configuration; however, the advanced oscilloscope user quickly sees the power and value in having this much data available at their fingertips. When all the channels are not needed, the MSO signals can be configured to be more spread out to make them easier to read.

Comparison of SLA1016 vs Logic Analyzers

The SLA1016 Mixed Signal option module competes against other traditional logic analyzers, both standalone units as well as PC based USB logic analyzers. Compared to purchasing a standalone logic analyzer, the SLA1016 is a fraction of the price and paired with the capabilities of the SDS1000X-E and SDS2000X-E oscilloscopes has a very expansive set of features. Standalone logic analyzers do not typically offer analog channels for measurement which may limit their capabilities depending on the project.

Click here to download the complete document.

The post SLA1016 Mixed Signal Oscilloscope Whitepaper appeared first on Siglent.

Generate a stereo-FM multiplex waveform with Python and AWG

The post Baltic Labs: Generate a stereo-FM multiplex waveform with Python and AWG appeared first on Siglent.

The basic idea is simple enough – measure the clock edges and see if they are all exactly evenly spaced or if they change (jitter) over time. A non-uniform clock fed to an ADC or DAC will produce FM and/or AM effects, as well as raise the noise floor. The effects of the clock jitter depend on the nature of the jitter. Random jitter can have less objectionable audible effects than jitter dominated by a specific frequency. There are many ways for interfering signals to couple into clock lines to cause problems.

The link below takes you to the note that looks at using a garden variety DSO (200 MHz BW, 1 Gsample/sec) to see if it can take the place of a $50,000 setup that would normally be wheeled out to investigate a jitter problem.

https://clk.works/2020/05/jitter-spectrum-measurement-with-a-dso/

The post Jitter spectrum measurements with a digital oscilloscope appeared first on Siglent.

Here is a table of features and options of our most powerful oscilloscopes to help decide what is best for you.

S – Standard, included

O – Optional

 (1) – Bode requires a SIGLENT SAG, SDG, or internal function generator to operate

(2) – Requires SIGLENT SAG hardware and activation license. The SDS2X Plus series has an internal function generator but still requires activation.

For convenience, click a link below to jump to the product of interest:

SDS6000A

SDS5000X

SDS2000X HD

SDS2000X Plus

SDS2000X-E

The post Oscilloscope Feature and Options Table appeared first on Siglent.

One method of quickly determining stability is to use a load step response.

In this test, a DC electronic load is used to provide a current load that steps from a low current draw to a higher value in a short period of time. By directly measuring the voltage and current output of the supply with the stepped load, we can visually observe the recovery of the power supply feedback loop and make changes to the design to optimize the response.

For this note, we are going to perform identical tests on two supplies and compare the output voltage and current waveforms: One has been tuned so that the output quickly recovers with minimal overshoot and ringing. The other supply is not tuned and subsequently oscillates. We will also discuss some measurement techniques to help get the right data as quickly as possible.

We also have a video to accompany this note:

Power Supply Design: Load Step Response with a SIGLENT DC Electronic Load

The Equipment:

• A DC Electronic Load: The SIGLENT SDL1020X-E is a 200 W load with dynamic testing capabilities to perform the load step. It also features remote sense capabilities to compensate for the voltage drop across the load leads. High currents can provide a substantial voltage drop across the leads and will add unwanted error.
• An oscilloscope: The SIGLENT SDS2354X Plus scope has a large display, easy-to-use interface, and features that make capturing these waveforms very easy.
• A power supply: The SIGLENT SPD1168X single output supply delivers power to our power supply board
• A current probe: The SIGLENT CP4070 features a 150 kHz bandwidth that will minimize most switching noise from the measurement
• Power supplies to test: The Analog Devices LTM4646 series of uModule Regulators. This module features two 10A DC-DC converters. One has been “detuned” to show some common problems associated with power supply design. The other supply has been left in it’s tuned state as a comparison to the detuned supply.

The Setup:

• Connect the SPD bench power supply to the power supply to test and configure the output values to match your supply needs. Here, we set the SPD for 12 V @ 3 A.

• Connect the SDL electronic DC load to the output of the power supply to test. Configure the load for Constant Current (CC), set the voltage and current ranges to the lowest ranges that still accommodate the requirements of the test, set the current load to a value near the maximum for your design. You may also wish to wire up and enable the SDL remote sense which enables remote voltage measurement to minimize the voltage drop caused by the high current flow through the electronic load leads. Here, we set the current to 5 A.

• Connect a passive probe to the oscilloscope CH1. This probe should be connected to the power supply feedback loop to monitor the voltage as the supply adjusts to the load.
• On the oscilloscope, configure CH1 for AC coupling to provide the most resolution to view the feedback voltage which can have high DC offsets. Enabling the Bandwidth Limit (BW limit) can also decrease noise. Here, the SDS2X Plus also has on-screen labels for traces, which can be a convenient way of keeping information organized. Here, I labeled CH1 Vout.

• Connect the current probe to the oscilloscope CH2.
• On the oscilloscope, set the trigger for Rising Edge, CH2 and AUTO. This will allow you to adjust the current probe zero position without dealing with the trigger setting.
• Configure CH2 as a current probe (Units = A), set the Probe attenuation to the proper value (50 mV/A in this case). DC coupling here because we want to see the total signal amplitude. I also applied a label to the output current (Iout).

• Zero the current probe. The CPs have a knob that you can use to move the DC offset. Set the scope to a low current range and adjust the probe to get 0 A on the display.

• Clip the current probe around the positive current lead going from the power supply under test to the DC load. Make sure to have the clamp connected such that positive current flow (into the load) produces a positive signal on the scope.

Now, everything is connected and ready to test:

Be on the lookout for interlopers and/or pesky critters wondering where the magic smoke came from:

DC Load Verification

Now, you can power on the SPD power supply and SDL load.

Make sure that the scope is set to AUTO trigger for now. You can also add an RMS measurement on CH2 so that you can verify the current draw matches the setting on the DC Load.

Here, we have a setting of 5 A on the DC load.. and we show 5 A RMS on the scope:

Things are looking good. The current output matches our load setting.

DC Load Step Response

Now, set the DC load to Dynamic Current mode by pressing Utility > CC.. and configure the appropriate ranges, low and high current values and duration, and slew rate for your application.

Here are the settings used for this test:

This will continuously cycle from 1 A for 5 ms to 5 A for 5 ms with 500 mA/us slew rate.

Now, switch the scope trigger mode to Normal and adjust the vertical, horizontal scales and positions.. as well as the trigger level to get a stable trigger and a few periods of transition on the display:

Verify that the supply high and low current values match the setpoints. For this example, we have 1 A for 5 ms and 5 A for 5 ms.. which is what we observe.

Observe and Optimize

Now, let’s compare a tuned setup to one that is not tuned for our load as well as some techniques to gather more information about the response.

First, you likely see quite a bit of noise on your signal. The majority of this is due to switching noise in the supply being tested. Here is a zoomed image of the feedback voltage where you can see the switching noise quite clearly.

Enabling waveform averaging can help:

Now, we see the output voltage from CH1 (yellow), output current from CH2 (pink/purple), and the average voltage math function (orange):

This is the tuned setup.

Now, let’s look at a detuned supply:

The scaling on these two images is exactly the same. You can see a large amount of ringing associated with the detuned supply. This design is very close to becoming an oscillator with this load. If our step duration was any shorter, the supply voltage wouldn’t be settled and our output would be very poorly regulated.

Here are some closer images of the rising and falling edges on shorter time scales:

Tuned, Rising:

Tuned, Falling:

Detuned, Rising:

Detuned, Falling:

Conclusions

A DC load step test can quickly show you the performance and stability of a power supply design. Using a few common pieces of test gear, you can ensure that your design is ready to undertake the most challenging application requirements.

The post Power Supply Design: Load Step Response with a SIGLENT DC Electronic Load appeared first on Siglent.

NOTE: This program saves the picture/display image file to the E: drive, which may or may not exist on the specific computer being used to run the application.

Download Python 3.4, connect a SIGLENT SDS Oscilloscope using a USB cable, get the scope USB VISA address, and run the attached .PY program to save an image of the oscilloscope display. The type of file saved is determined by the instruments setting when the program is run.

You can download the .PY file here: PyVISA SDS Screen Capture

Tested with:

Python 3.4

SDS1102CML+

#Example that returns a copy of the displayed image on SIGLENT SDS
#Oscilloscopes via USB and saves to a drive location
#
#Dependencies:
#Python 3.4 32 bit
#PyVisa 1.7
#
#Rev 1: 02262020 JC

import visa
import time # for sleep

def main():
 _rm = visa.ResourceManager()
 sds = _rm.open_resource("USB0::0xF4EC::0xEE3A::SDS1MFCQ3R5086::INSTR") #Replace with specific USB information from scope
 file_name = "E:\\SCDP.bmp" #Make suere that the drive specified is available on your computer
 sds.write("SCDP")
 result_str = sds.read_raw()
 f = open(file_name,'wb')
 f.write(result_str)
 f.flush()
 f.close()
if __name__=='__main__':
 main()

The post Programming Example: SDS Oscilloscope save a copy of a screen image via Python/PyVISA appeared first on Siglent.

You can download the VI here: VISA_IDN.ZIP

In this example, the user can:

• Select the connected instruments from the VISA Resource List drop down menu:

NOTE: USB devices will automatically appear. For LAN connections, you will need to add the device. This is commonly done using NI Measurement and Automation Explorer (NI-MAX)

• Request the identification string once-per-press of the RUN button.

This sends the “*IDN?” identification query string to the instrument. The instrument then responds to the query with its identification string information. The identification string data will appear in the text box.

This code also uses the event structure connected to the value change of the RUN button to run once-and-only-once per keypress. This is a useful method of controlling code execution.

• Stop and exit upon pressing the STOP button

To run:

1. Connect instruments using a USB or LAN connection (see users manual for specific instrument details)
2. Power on instrument
3. Open LabVIEW and select the IDN.VI. This will open the VI front panel:

4. Select the instrument of interest from the VISA Resource drop down menu:

5. Press RUN on the LabVIEW VI menu strip to run the program:

6. Now, the “graph paper” background goes clear, indicating that the code is running. Now, you can press RUN in the VI Front Panel to execute the code:

The identification string should appear in the textbox:

7. Press STOP on the VI Front Panel to exit the code

The post Programming Example: Identification String (*IDN?) return with LabVIEW 2018 appeared first on Siglent.

Stability is one of the most important characteristics in power supply design. Traditionally, stability measurements require expensive frequency response analyzers (FRA) which are not always available in a laboratory. SIGLENT has released Bode Plot Ⅱ features to the SIGLENT SDS1104X-E, SDS1204X-E, SDS2000X-E, SDS2000X Plus, SDS5000X, and SDS6000A series of oscilloscopes. When combined with a Siglent arbitrary waveform generator (SDG or SAG) and an injection transformer, quick frequency response curves can be created.

In this application note, we will show you the basic principles for making this stability measurement and how to use these instruments to make the measurement.

Figure 1: Bode II setup

1. Basic Principle of Stability Measurement

1.1 Stability of The Feedback System

A regulated power supply is actually a feedback amplifier with a large amount of current sourcing capability. Any theory that applies to a basic feedback amplifier also applies to a regulated power supply.

In feedback theory, the stability of a feedback system can be determined by evaluating the loop transfer function. A more practical way is to measure the bode plot of the loop gain. Figure 2 shows a typical feedback system.

The closed loop transfer A is the mathematical relationship between input x and output y. The loop gain T, by its name, is defined as the gain of a signal traveling around the loop.

Figure 2: Typical Feedback Loop

Since α and β are complex variables, they have not only magnitude but also phase angle, as also does the loop gain T. If the phase angle of T reaches -180° while the magnitude is 1, the closed-loop transfer function A becomes infinity. In this situation, the system will maintain an output signal while there is no input. Thus, the system acts as an oscillator rather than as an amplifier, which means that the system is not stable.

If we plot the loop gain in a bode plot, we can evaluate the stability by finding the phase margin and gain margin. A phase margin is defined as how many degrees the phase can be decreased before reaching -180°while the magnitude is 1 (or 0 dB). The gain margin is defined as how many dB in magnitude can be added before reaching 1 (or 0 dB) while the phase is -180°.

Figure 3: Bode Plot, phase, and gain margin

1.2 Break the Loop

To get the desired loop gain, we simply break the loop. Figure 4 shows how to break the loop in a typical feedback system. Technically you can break the loop any place you like. We commonly choose to break the loop at the point between the amplifier output and the feedback network. Then we insert a test signal i to travel around the loop. The loop gain is the mathematical relationship between the output y and the test signal i.

Figure 4: Breaking the loop in a typical feedback system

1.3 Loop Injection

 In reality, we can never really break the loop because the feedback loop serves to maintain the DC quiescent operation point of the circuits. Without the feedback loop, the device under test will become saturated because of the small input offset voltage, and then no useful result can be measured.

To overcome this, we should measure the open-loop response inside a closed loop. Therefore, we just inject a signal into the loop rather than breaking the loop. Figure 5 shows a typical method of loop injection. The injection point is chosen so that the impedance looking in the direction of the loop is much higher than that looking backward. One possible point is between the output and the resistor divider feedback network. Other points that meet this requirement may be chosen.

Figure 5: Loop injection

To maintain the closed loop, a small injection resistor Ri is inserted at the injection point. The resistor should be small enough so that it will have little effect on the circuit and also the lower the resistor value the lower the frequency the transformer will operate. Picotest recommends a resistor value of 4.99 Ω for the J2100A, and a larger value may be chosen depending on the circuits. The injection signal is then applied across the injection resistor.

The signal injected should have no effect on the DC operating point of the circuit. A method to solve the common ground connection problem is to use an injection transformer as shown in Figure 6.

Figure 6: Injection Transformer

The injection signal starts at one end of the injection resistor, travels through the resistor divider feedback network, the error amplifier and the pass element transistor, and finally to the output, which is the other end of the injection resistor. The relationship between the injection signal i  and the output signal y is the loop gain that we wish to measure.

Be aware that we are measuring an open-loop parameter inside a closed loop, the phase starts at 180°and decreases to 0°, rather than starting at 0°and decreasing to -180°. So the phase margin should be measured relative to 0°.

2. Measurement Setup and Result

2.1 Equipment

Oscilloscope: Siglent SDS1204X-E with firmware version higher than 6.1.27R1 (Bode Plot Ⅱ release)

Signal Source: Siglent SDG2042X

Power Supply: Siglent SPD3303X

Probe: Siglent PP215 passive probe switched to 1X

Injection Transformer: Picotest J2100A

Device-Under-Test: Picotest VRTS v1.51

2.2 Circuit Connection

 The Picotest VRTS v1.51 is a demonstration board for voltage regulator testing. Technically it is a linear regulator built from the famous TL431 and a discrete transistor. The schematic is shown in Figure 7. Different output capacitors can be selected to see the impact on the control loop stability.

Figure 7: VRTS v1.51 schematic

For the propose of our power supply control loop response measurement, the injection point is TP3 and TP4. The circuit connection is shown in Figure 8.

The generator is connected to the oscilloscope through USB (connection through Ethernet is also supported).

The injection transformer is connected in parallel with the injection resistor so that the signal is injected to the loop while preventing the circuit DC operation point from being affected by the generator.

The TP3 and TP4 points are also connected to the oscilloscope, and the TP4 is defined as the DUT Input while the TP3 is the DUT Output in the Bode Plot Ⅱ.

Figure 8: Circuit connection

Figure 9: Probe and Transformer connections to the DUT

2.3 Instrument Configuration

In this section, we will show how the key configuration should be made in order to make the measurement correctly. For complete instructions to the Bode Plot Ⅱ, please refer to the user manual and the quick start guide.

Before entering the Bode Plot Ⅱ, it is recommended that you enable the oscilloscope’s 20 MHz bandwidth limit setting.

At this time, we want to measure the bode plot from 10 Hz all the way to 100 kHz. This frequency range should be enough for a circuit with an expected crossover frequency at about 10 kHz.

Enter the Config menu and set the Sweep Type to Simple, then enter Set Sweep to set the sweeping frequency. Set the Mode to Decade and Start to 10 Hz, Stop to 100 kHz. Set Points/dec to 20, enough for a typical sweep. Enter the Set Stimulus menu to set Amplitude to 50 mV. Enter the Set Channel menu to set DUT Input to CH1 and DUT Output to CH2.

Figure 10: Bode II scope configuration

2.4 Results and Data analysis

After the configuration is done, return to the main menu and press Run to start the sweep.

Wait to see the results as shown in Figure 11.

The result is somewhat confusing and suspect because of the trace at low frequency, especially the phase trace, alternating up and down. We will introduce a method called Vari-level to resolve this problem in the next section.

Figure 11: Measurement results

After the sweep has completed, press Run again to stop the sweep. Enter the Display menu and then enter the Cursors menu to turn on the cursors. Use the Adjust knob to move the cursors and set the phase margin as shown in Figure 12.

Figure 12: Cursor measurement on the Bode plot

You can also turn on the List feature in the Data menu to examine the measured data, or you can export the data to an external USB FLASH driver for further analysis on a computer.

Figure 13: Exporting data

2.5 Vari-level

In the previous section, we can see that the results are not ideal, for the bouncing trace at low frequency. This is because at low frequency the amplitude difference between the input and output channel is relatively large, and since we are using a relatively small stimulus signal (this time 50 mVpp), the signal presented at the DUT Input channel is extremely small so that a commercial general propose oscilloscope cannot measure it accurately.

But we cannot simply increase the stimulus’s signal amplitude. The result will be similar to what is shown in Figure 14. The large signal near the crossover frequency region causes serious distortion to the loop. The distorted signal in the time domain is shown in Figure 15.

Remember that a bode plot only makes sense in a linear system, and has no meaning in a heavily non-linear system. The result is useless.

Figure 14: Increased stimulus signal amplitude and distortion

Figure 15: Distortion in the time domain

One possible solution to the problem is Vari-level (other manufactures may call it “Shaped Level” or “Level Profile”). The Vari-level concept is simple: The stimulus signal amplitude is variable over the frequency. If we use a large signal at low frequencies and decrease the amplitude to a fairly small level near the crossover region so that it causes little distortion to the loop, in theory, we can get an ideal result.

Under the Configure menu, set Sweep Type from Simple to Vari-level, and push Set Vari-level to enter the Vari-level profile editor.

Figure 16: Set Sweep Type to Vari-level

Figure 17 shows the Vari-level profile editor. The Profile option allows the user to select and save up to 4 profiles. The Nodes sets the number of nodes in the profile trace, the minimum allowed number of nodes is 2 because at least 2 points can determine a line, and always the first and the last node set the start and stop of the trace. Press Edit Table will enter the profile editor mode. The parameter under editing is highlighted by cursors, and next push Edit Table again to cycle the cursors between “Freq”, “Ampl” and the entire row, which allows the user to navigate through the entire table. Users can use the Adjust knob to set the highlighted parameter, and pushing the knob will call out a visual keypad that allows direct input to the parameter. The Set Sweep and Set Stimulus option is somewhat similar to that in the Simple type of sweep, but they are not correlated. This time we set the sweep Mode to Decade and a 40-point-per-decade is sufficient. The profile shown in Figure 17 is used in this measurement. It is not the optimum profile for this circuit but should be a good place to start.

Figure 17: Vari-level profile editor

In practice, one should always experiment with those parameters to find an optimum solution for a particular circuit.

One practical way to do this is to monitor the signal in the time domain, decrease the amplitude of the stimulus signal until no visible distortion can be observed, then decrease the amplitude by another 6 dB. Next, record the amplitude and frequency, jump to another frequency and repeat the process.

There is a better way to find the optimum profile if you already have a known good profile. Reduce the signal amplitude by 6 dB and run a sweep to see if the plot changes. If it does change, reduce the amplitude by another 6 dB and sweep again. Until the result doesn’t change, then you can increase the amplitude by 6 dB and that’s an optimum profile. This is time-consuming but necessary to get a meaningful result.

Once profile editing is completed, return to the main menu and push Run to start the sweep. Figure 18 shows the final result of the measurement with Vari-level. Changing the capacitor selection switch S1 on the VRTS v1.51 demo board will alter the loop response due to the impact of different capacitors.

Figure 18: Results with Vari-level

3. Summary

 The Siglent oscilloscope with newly released Bode Plot Ⅱ together with a Siglent signal generator and a Picotest injection transformer offer a very flexible and easy-to-use power supply control loop measurement system.

The post Measuring Power Supply Control Loop Response with Bode Plot II appeared first on Siglent.

NOTE: This program saves the picture/display image file in the same directory that the .py file is being run from. It will overwrite any existing file that has the same name.

Download Python 3.4, connect a scope to the LAN using an Ethernet cable, get the scope IP address, and run the attached .PY program to save a bitmap (BMP) image of the oscilloscope display.

You can download the .PY file here: Python_Socket_SDS_SCDP.zip

Tested with:

Python 3.4
SDS1202X-E
SDS1104/1204X-E
SDS2000X-E Models
SDS5000X Models

#!/usr/bin/env python 3.4.3
#-*- coding:utf-8 –*-
#-----------------------------------------------------------------------------
#The short script is a example that open a socket, sends a query to return a
#screen dump from the scope, saves the screen dump as a BMP in the python folder,
#and closes the socket.
#
#Currently tested on SDS1000X-E,2000X-E, and 5000X models
#
#No warranties expressed or implied
#
#SIGLENT/JAC 03.2019
#
#-----------------------------------------------------------------------------
import socket # for sockets
import sys # for exit
import time # for sleep
#-----------------------------------------------------------------------------

remote_ip = "192.168.55.100" # should match the instrument’s IP address
port = 5025 # the port number of the instrument service

def SocketConnect():
    try:
        #create an AF_INET, STREAM socket (TCP)
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    except socket.error:
        print ('Failed to create socket.')
        sys.exit();
    try:
        #Connect to remote server
        s.connect((remote_ip , port))
        s.setblocking(0) # non-blocking mode, an exception occurs when no data is detected by the receiver
        #s.settimeout(3) 
    except socket.error:
        print ('failed to connect to ip ' + remote_ip)
    return s

def SocketQuery(Sock, cmd):
    try :
        #Send cmd string
        Sock.sendall(cmd)
        Sock.sendall(b'\n') #Command termination
        time.sleep(1)
    except socket.error:
        #Send failed
        print ('Send failed')
        sys.exit()

    data_body = bytes() 
    while True:
        try:
            time.sleep(0.01)
            server_replay = Sock.recv(8000)
            #print(len(server_replay))
            data_body += server_replay
        except BlockingIOError:
            print("data received complete..")
            break
    return data_body
    '''
    PACK_LEN = 768067#the packet length you will receive;
    #SDS5000X is 2457659;SDS1000X-E/2000X-E is 768067
    had_received = 0    
    data_body = bytes() 
    while had_received < PACK_LEN:
        part_body= Sock.recv(PACK_LEN - had_received)
        data_body +=  part_body
        part_body_length = len(part_body)
        #print('part_body_length', part_body_length)
        had_received += part_body_length
    return data_body
    '''


def SocketClose(Sock):
    #close the socket
    Sock.close()
    time.sleep(5)

def main():
    global remote_ip
    global port
    global count

    #Open a file
    file_name = "SCDP.bmp"

    # Body: Open a socket, query the screen dump, save and close
    s = SocketConnect()
    qStr = SocketQuery(s, b'SCDP') #Request screen image
    print(len(qStr))
    f=open(file_name,'wb')
    f.write(qStr)
    f.flush()
    f.close()

    SocketClose(s)
    sys.exit

if __name__ == '__main__':
    proc = main()

The post Programming Example: SDS Oscilloscope screen image capture using Python over LAN appeared first on Siglent.