Tryout: LabNation SmartScope

Written by: Martin Rowe – October 09, 2015 – EDN Network – http://www.edn.com

Over the last few years, USB oscilloscopes have certainly grown in usefulness and in popularity. Unless you need the highest speed, you can probably find a USB oscilloscope to meet your need at prices from around $100 to several thousand dollars, depending on speed, bandwidth, and features. The SmartScope from start-up company LabNation may come in at the low end of that price range, but is has an array of features that go beyond just a basic oscilloscope. With some improvements, it could make a worthy tool for your home bench or toolbox.

Touted as an oscilloscope by and for makers, the SmartScope’s claim to fame is its ability to operate under a wide range of operating systems: Windows, Linux, Mac OS, Android, and iOS. I tried it on a Windows 7 laptop because I don’t have an Android device (using my wife’s phone is out of the question) and to use iOS, you first have to “jailbreak” the device. Plus, many engineers would rather use a laptop computer for real work, anyway.

Over the next few pages, I’ll show you how the SmartScope looks, feels, and works. I’ll look at it feature by feature.

  • Analog channels
  • Logic analyzer & bus decoder
  • Waveform generator
  • FFT and waveform math
  • Observations and conclusions

The SmartScope comes in a solidly-built metal case that should act as a good EMI shield for both emissions and immunity. One end of the unit holds the usual BNC connectors for its two analog channels. The opposite end contains a mini-USB connector that communicates with the host device. A micro-USB connector lets you attach a power bank should you need additional battery power in a portable application (the SmartScope is bus powered) and for synchronizing additional units when you need more channels. A 16-pin AUX I/O connector provides access to an external trigger input, the AWG (arbitrary waveform generator) output, eight logic inputs, and four general-purpose digital I/O lines. Two pins provide ground connections.

The box (Figure 1) contains two 60-MHz analog oscilloscope probes, eight clip leads for the digital inputs, and a ten-line ribbon cable that lets you connect to the I/O connector. You also get a mini-USB cable and a micro-USB cable.

Pic 1

Figure 1. The LabNation SmartScope comes with probes for analog and digital inputs.

Software installation and startup
Before connecting the SmartScope to my laptop PC, I downloaded the software and tried to install v4.1.2. LabNation requires that your Windows PC have Microsoft .NET 4.0 or higher, which mine didn’t. The SmartScope software attempted to download and install .NET, but failed. I downloaded the latest .NET version manually. After that, the SmartScope software installed without a glitch.

On initial startup, the SmartScope software displays a help menu (Figure 2) that shows you how to control basic oscilloscope functions such as time and voltage scales, viewfinder, and waveform movement using touch, mouse, and keyboard operations. You can invoke the help by pressing the F1 key. I found myself referring to this screen several times during my tryout. If you need more help, you can view the manual online.

Pic 2

Figure 2. The help screen shows you how to operate the SmartScope’s basic controls.

Take note of how to change voltage and time scales with a mouse. The software designers assumed you’d use an external mouse because to change those settings—you must use the scroll wheel. When I started this evaluation, I was using the laptop’s mouse pad. Without the external mouse, you must use the keyboard to change voltage and time settings. At that point, I connected a mouse.

The heart of any multifunction oscilloscope is, well, the oscilloscope. The SmartScope has two analog channels with the ability to add more channels by adding more units through the micro-USB port. When you start the software, it defaults to a light shaded screen, which you can change to a dark screen. After you clear the help menu by clicking somewhere outside of it, you’ll see a screen something like that in Figure 3. The waveform shown is just stray 60 Hz AC, which the probe and cable picked up.

Pic 3

Figure 3. The basic screen lets you view analog channel specifics by clicking on the ChA or ChB buttons as well as seeing system characteristics.

The screen in Figure 3 shows the oscilloscope grid consuming the entire PC screen. Clicking on the LabNation icon in the lower-left corner brings up a configuration menu, shown in Figure 4. I started testing with a basic signal, a 1 kHz, ±2 Vpk-pk sine wave generated by an old HP oscilloscope demo board.

Pic 4

Figure 4. The analog oscilloscope lets you see the portion of the waveform that’s displayed on the screen.

Note the colored “band” that highlights the minimum and maximum peaks. No other oscilloscope I’ve used shows this band, which seems to indicate which channel you’ve selected. Clicking outside the waveform’s peaks turns the band off. Is it a feature or a bug?

For triggering, the SmartScope has three options that are accessible from the trigger menu on the bottom left side of the screen.

  • auto triggering
  • require trigger
  • single trigger

“Require trigger” is an odd choice of name. We’re used to seeing “Ext. Trigger” as a trigger option.

To select the trigger type, such as edge trigger (rising or falling), click on the trigger circle to the right of the grid. You can then move the circle to raise or lower the trigger level.

I found the waveform trace difficult to see on the light (standard) background; I prefer a dark oscilloscope grid. The System menu in Figure 4 lets you change to a dark display. Figure 5 shows the same waveform using the dark display. Unfortunately, you’re stuck with orange color for ChA and blue for ChB, but at least they are both visible on the light and dark displays, more or less.

Pic 5

Figure 5. I much prefer the dark display. Unfortunately, you can’t change the waveform color.

Next, I generated a signal using a National Instruments VirtualBench system, which served as a “sanity check” for the SmartScope. The 1 kHz sine wave looked essentially identical on both screens.

While a 1 kHz sine wave let me see that the SmartScope worked, it’s not all that useful. Using the VirtualBench function generator, I set up a 5 MHz square wave. Remember that the SmartScope’s rated bandwidth is 30 MHz, which is enough to retain the fifth harmonic of the square wave, with some margin. I used a BNC-to-BNC cable to connect the VirtualBench function generator to the SmartScope’s input channel B. Here’s the waveform displayed first on the VirtualBench screen (Figure 6). You can see what looks like ringing.

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Figure 6. A 5 MHz square wave shown on a National Instruments VirtualBench system.

Figure 7 shows the same waveform on the SmartScope screen. Here, you can see how its lack of bandwidth distorts the signal, rounding off the corners. As expected, the SmartScope’s low bandwidth produced the same result at 1 MHz. That’s because it still filtered out the high frequency content in the waveform’s rising and falling edges.

Pic 7

Figure 7. The SmartScope’s 30 MHz analog bandwidth distorts even relatively low-frequency signals.

Figure 8 shows a close-up of the waveform as measured on the VirtualBench, Here, ringing on the square wave’s rising edge is clearly visible, not so on the SmartScope.

Pic 8

Figure 8. Ringing on the waveform was lost with the lower-bandwidth SmartScope.

The LabNation Smartscope provides eight logic inputs for debugging digital designs. Here, I found the software easy to use for both the logic analysis and serial-bus decoding functions, but the provided hardware was awkward to use.

To get eight logic signals, I returned to the old HP demo board. Because the board already had a pin header, I used the SmartScope’s ten-wire ribbon cable (Figure 9) to connect between the AUX connector and the demo board. While the color coding is helpful, I can just see myself separating the wires for the next application, then losing a few.

Pic 9

Figure 9. This ribbon cable provides access to the SmartScope’s AUX connector. 

Figure 10 shows a nice feature of the SmartScope software, for it displays the time between transitions. If you click on any channel, you’ll get those measurements. Moving the mouse over another channel displays the measurements for that channel while retaining the clicked-on channel’s measurements. Before taking the image, I had clicked on channel 4, then scrolled the mouse over channel 3 to channel 2, then captured the screen image.

Pic 10

Figure 10. The SmartScope automatically displays the time between transitions when using the digital inputs.

You can set up a pattern trigger based on the digital inputs. Clicking on the right side of each signal unfolds a menu where you can select logic 1, logic 0, rising edge, falling edge, or don’t care condition.

Serial bus decoder
The SmartScope has several serial bus decoders that you can apply to analog or digital channels. I tried the decoder using digital channels. My test bus came from a Rohde & Schwarz demo board, which generates SPI, I2C, CAN, and UART signals. I used the board’s SPI output and connected the board to the SmartScope through three wires. Here’s where making the connections was difficult.

Figure 11 shows four clips connected to the demo board. While it looks easy to do, the jaws that extrude from the clip’s housing are at an odd angle to the housing. They will force you to rotate your hand by 90 degrees from what is most comfortable. The same applies when using the clip to connect to an SMT IC package lead. Connecting to the board was even more awkward because I didn’t want to separate the individual wires from the supplied ribbon cable. The clips fell off several times.

Pic 11

Figure 11. Connecting the clips to a target may look easy here, but it was awkward.

I used one analog channel to verify that the demo board was producing signal, which it was. Then, I connected digital channels D0, D1, and D2 to the board’s SPI port. At first, the SmartScope didn’t show anything until I realized the ribbon cable wasn’t on the right AUX connector pins. Once properly connected and with the decoder set to SPI through the main menu, the SmartScope displayed the following decoded waveform (Figure 12).

Pic 12

Figure 12. The SmartScope decoded data from an SPI bus input.

The SmartScope has a function/arbitrary waveform generator that you can use to create test signals. Accessible from the AUX connector, the waveform generator produces the usual sine, square, triangle, and sawtooth waves plus sawtooth+sine and multisine signals. It also lets you upload arbitrary waveforms from a local file or from Dropbox. From the AWG menu, you can use sliders to set the signal’s frequency, amplitude, and amplitude modulation. In addition to using the sliders, you can activate a virtual keypad to enter your desired values. Invoke the keypad by double-clicking on any of the numbers in the AWG menu. If you use the dark color scheme, the keypad’s numbers will be invisible. The software should know which color scheme you’re using at adjust colors accordingly. Figure 13 shows the keypad, but with the numbers invisible.

Pic 13

Figure 13. A keypad for entering waveform values is partially hidden when using the dark color scheme.

After setting up a sine wave, I was ready to try it, but the SmartScope gave no output. I checked the AUX connector three times and I was using the right pin. There was no indication of how to enable the AWG. At that point, I had to refer to the online manual for help. To start the waveform, you must click on the “Upload function” choice in the menu, shown in Figure 13.

The SmartScope has rather limited math functions, which should be expanded in future software revisions. All you get for math is ChA+ChB. The LabNation engineers should at least add A-B and A×B functions.

I then went back to the analog oscilloscope to try the FFT (Fast Fourier Transform) feature, which is essential for almost any kind of troubleshooting. I used the 5 MHz square wave to try the FFT. The resulting frequency plot was almost as expected.

With the SmartScope, you get a nice selection of windows to apply to a time-domain signal before converting to the frequency domain. Windows include Blackman-Harris, Hamming, Hanning, Flat Top (rectangular), Kaiser-Bessel, and Uniform.

After you set the FFT parameters, a frequency plot appears below the time-domain plot. As expected, I saw peaks at the fundamental 5 MHz frequency and odd harmonics, 15 MHz, 25 MHz, etc. But the peaks were much wider than I expected (Figure 14). Changing the window function didn’t help. When I stopped the oscilloscope, the peaks became narrow spikes, more like I expected. See Figure 15.

Pic 14

Figure 14. While the oscilloscope ran, FFT peaks were wider than expected.

Pic 15

Figure 15. Once the oscilloscope stopped, FFT peaks became narrow.

The $229 SmartScope has potential as a troubleshooting tool, but it has its quirks and needs some improvements.

  • The oscilloscope needs something on the screen to let you adjust vertical and horizontal resolution. With the PC version (no touch screen), you must use your mouse’s scroll wheel or keyboard. LabNation needs to add onscreen boxes that you can click or touch to change voltage and time settings. Most oscilloscope users expect that. Some PC-based USB oscilloscopes even have virtual knobs.
  • There is no Autoset feature. Oscilloscope users expect that now.
  • Users need the ability to change waveform colors.
  • Add a DMM (digital multimeter). That software upgrade will add value to the SmartScope.
  • The logic probe clips are hard to use. They come apart easily.
  • Add a pulse-width trigger.
  • Add a button to save a screen image to disk. You shouldn’t need to use print-screen to get an image.
  • Add a 16-pin connector to the kit with easy-to attach wires or pins instead of having the ten-wire ribbon cable. That will make connecting to the AUX connector easier and prevent the loss of wires once they come apart from the others on the ribbon cable.
  • The digital-signal clips have a sharp pin on their top that extrudes from the housing. It’s for attaching the connectors on the ribbon-cable’s wires. When cleaning my bench after the evaluation. I grabbed the clips in my hand. Those pins can puncture your skin.

In a conversation with me held prior to the SmartScope’s release in September, LabNation’s Reimer Grootjans said “To appreciate the SmartScope, you need to use it with a tablet or smart phone and the pinch interface.” He also claimed that the SmartScope is a tool for makers, who tend to be software developers. “If they can’t use the touch screen,” he said, they will think the device is broken.” Perhaps, but anyone who has ever used an oscilloscope before will have expectations that the SmartScope doesn’t meet at this time. In some ways, I had the distinct feeling that the LabNation user interface was designed for touch screens, with the traditional PC interfaces as afterthoughts.

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor that specializes in providing unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers. You can visit our website at http://www.northtreeassociates.com for more information on the LabNation SmartScope

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9 Factors to Consider When Choosing an Oscilloscope

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If you’re involved in electronics, you’ll probably have an oscilloscope on your bench. As electronics become more complex almost daily, sooner or later a new oscilloscope will be in order. How to choose the right one for your applications?

Factors to consider:

Remember that the bandwidth specification of an oscilloscope is the frequency of the “-3 dB point” of a sine-wave signal of a particular amplitude, e.g. 1 Vpp. As the frequency of your sinewave goes up (while keeping the amplitude constant), the measured amplitude goes down. The frequency at which this amplitude is -3 dB lower, is the instrument’s bandwidth. This means that an oscilloscope of 100MHz would measure a 1Vpp sinewave of 100MHz at only (approx.) 0.7Vpp. That is an error of about 30%! In order to measure more correctly, use this rule of thumb: BW/3 equals about 5% error; BW/5 equals about 3% error. In other words: if the highest frequency you want to measure is 100 MHz, choose an oscilloscope of at least 300MHz, a better bet would be 500MHz. Unfortunately, this has the most influence on the price…

Understand that today’s signals are no longer pure sine waves, but most of the time square waves. These are built by “adding” the odd harmonics of the fundamental sine wave together. So a 10 MHz square wave is “built” by adding a 10MHz sine wave + a 30MHz sine wave + a 50MHz sine wave and so on. Rule of thumb: get a scope that has a bandwidth of at least the 9th harmonic. So if you’re going for square waves, it’s better to get a scope with a bandwidth of at least 10x the frequency of your square wave. For 100MHz square waves, get a 1GHz scope… and a bigger budget…

Consider rise (fall) time. Square waves have steep rise and fall times. There’s an easy rule of thumb to get to know what bandwidth your scope needs to be if these times are important to you. For oscilloscopes with bandwidths below 2.5GHz, calculate the steepest rise (fall) time it can measure as 0.35/BW. So an oscilloscope of 100MHz can measure rise times up to 3.5ns. For oscilloscopes above 2.5GHz up to about 8GHz, use 0.40/BW, and for scopes above 8GHz use 0.42/BW. Is your risetime the starting point? Use the inverse: if you need to measure rise times of 100ps, you’ll need a scope of at least 0.4/100ps = 4 GHz.

Choose your sample speed. Today’s oscilloscopes are almost all digital. The above steps involved the analog part of the instrument, before it gets to the A/D converters to get “digitized”. Here the bandwidth-to-rise time calculation can help you out: an oscilloscope of 500MHz has a calculated rise time of 700ps. To reconstruct this, you need at least 2 sample points on this edge, so at least a sample each 350ps, or 2.8Gsa/s (gigasamples per second). Scopes don’t come in this flavor, so choose a model with a faster sampling speed, e.g. 5Gsa/s (resulting in 200ps “time resolution”).

Decide on the number of channels. This is easy: most scopes come with 2ch or 4ch configurations, so you can choose what you need. Fortunately prices don’t double from 2ch to 4ch, but it does have a big impact on the price of the instrument. High-end scopes (>=1GHz) have always 4ch.

Calculate how much memory you’ll need. Depending on how much of your signal you want to see in a “single shot acquisition”, get your math right: at 5Gsa/s, you have a sample each 200ps. A scope with a memory of 10.000 sample points, can store 2µs of your signal. A scope with 100M samples (they do exist!) can store 20 seconds! Looking at repetitive signals or “eye-diagrams”, memory is less important.

Think about repetition rate. A digital oscilloscope uses a lot of time calculating. Between the moment of triggering (see next step), having the captured signal on the display, and capturing the next triggered event, most digital scopes “consume” several milliseconds. This results in only a few “photos” of your signal each second (waveforms per second), typically about 100-500. One vendor solved this problem with so called “Digital Phosphor” (from about 4.000 wfms/s to >400.000 wfms/s for the top models), others followed with similar-like technologies (but not always sustained/continuous, rather in bursts). This repetition rate is important because those rare errors and faults in your signal might occur just then when the scope is not acquiring, but busy calculating the last taken acquisition. The higher the repetition rate (wfms/s rate), the higher your chances are of capturing that rare event.

Check what kind of errors you expect to be looking for. All digital scopes have some sort of intelligent triggers on board, meaning you can trigger on more than just the rising or falling edge of your signal. If your repetition rate is high enough, you’ve probably seen that rare glitch every other second. Then it’s nice to have a Glitch trigger.

Think about resolution of LCD display. Small screens with poor resolution can make your life miserable if you cannot see results easily. Buy the largest screen with the best definition your budget will allow.

Some Final Tips

  • Triggering, repetition rate and memory: once you found the rare event with a high wfms/s rate, having the right trigger available is more important than repetition rate, as your scope will trigger only on the (rare) event, which occurs… right: rarely. So you don’t need high rep-rate anymore. Memory can become more important, as to be able to analyze what happened before or after the event.
  • Remember: garbage in is garbage out, so get the bandwidth and rise time issue sorted out first!

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor that specializes in providing unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers. You can visit our website at http://www.northtreeassociates.com

LabNation SmartScope Open Source USB Oscilloscope

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LabNation has announced the launch of an open source USB oscilloscope dubbed SmartScope. Using a Kickstarter campaign that started in 2014, the project raised 645% of its funding goal within 30 days. Believed to be the world’s first test equipment designed to run on multiple operating systems and platforms such as smartphones, tablets and PCs, the SmartScope is powered directly from the host’s USB interface.

The SmartScope combines the multiple functions of an oscilloscope including a logic analyzer and a waveform generator in a case measuring just 110.0 x 64.0 x 24.2 mm, weighing only 158 grams. The software provides the user interface and functionality, and can be downloaded from the SmartScope website. It is available for Android (Google Play Store or LabNation website), Apple Mac OS X, Apple iOS (jailbroken), Microsoft Windows 7, 8 and 10, and Ubuntu and Debian Linux distributions.

The oscilloscope provides two analog channels with a sample rate up to 100 MS/s and provides a -3dB bandwidth of 30 MHz, input signal range of ±35 V with a 1 MΩ / 1pF impedance, an 8-bit precision and a maximal resolution of 2.5mV.

The LabNation SmartScope oscilloscope software provides a comprehensive set of on-screen functions, either by touch, mouse or keyboard controls, for voltage scaling, time-based scaling, panning, input coupling, triggering and simple voltage measurements. The logic analyzer offers eight input channels with a user selectable logic level of 3.3 or 5 VDC. The application includes a number of standard protocol decoders such as I2C and SPI in addition to allowing the creation of custom decoders. The single channel waveform generator creates arbitrary waveforms with a data rate up to 50 MS/s and an output level from 0 to 3.3 V.

A digital output generator provides four channels, up to a rate of 100 MS/s at either 3.3 or 5 V. The LabNation SmartScope is ideal for the growing numbers of makers using small board computers such as Raspberry Pi and Arduino to diagnose faults and learn more about how basic electronics and how their design is functioning. The light compact unit suits a broad variety of electronics engineering, field service, education, and hobbyist applications. The small form-factor unit is supplied complete with a mini ‘B’ USB cable, two analog probes, digital cable and probes.

NorthTree Associates has represented LabNation SmartScope since 2014. Contact us with any questions or comments concerning the LabNation SmartScope or any of the other fine products we sell. www.northtreeassociates.com

10 Reasons Why You Need A PC Oscilloscope

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PC Oscilloscopes (PCOs) are rapidly replacing traditional digital storage oscilloscopes (DSOs) as the essential item for your test equipment arsenal. Here are 10 reasons why:

  1. Compact and portable units
  2. Uses your PC monitor to provide a large and detailed color display
  3. Signal storage is limited only by your PC’s storage capability
  4. Captured waveforms and instrument settings can easily be shared with others
  5. New functionality through free software updates
  6. Can be used with desktop or laptop PCs
  7. High-speed USB 3.0 connection (parallel port oscilloscopes are also available)
  8. Hardware and software in one package
  9. Use your PC Oscilloscope for data acquisition
  10. A complete test and measurement lab in one unit

1.  Compact and portable units

By integrating several instruments into one small unit, PC Oscilloscopes (PCOs) are lighter and more portable than traditional test equipment. When used with a laptop computer, you can carry a complete electronics lab in the same bag as your PC.

2.  Uses your PC monitor to provide a large and detailed color display

The display of a traditional oscilloscope is limited by the physical size of the oscilloscope, and may only be a single color. With a PC Oscilloscope your computer controls the display, so not only do you get a full color display, but the display can be the size of your monitor, projector or plasma display.

3.  Signal storage is limited only by your PC’s storage capability

PC Oscilloscopes store the signals that you are measuring directly on your PC. With the power of today’s modern PCs this gives you vast storage capabilities. Along with allowing you to record lengthy signals this also lets you save signals for reviewing at a later date.

4.  Captured waveforms and instrument settings can easily be shared with others

Need to show your customer or colleague the signal you have captured? Just save the waveform and email them a copy. They don’t have a copy of the oscilloscope software? No problem – just export it as text, an image or in a binary format for use with third-party software. (If they want to set up their equipment to run the same test, simply send them the oscilloscope settings too.)

5.  New functionality through free software updates

If you’re lucky you can return a traditional DSO to the supplier for a firmware upgrade and maybe get improved functionality. With a PC-based oscilloscope new features and improved functionality can be added at any time with a simple software update. Free software updates means that a PC Oscilloscope is one of the few things that can actually become more powerful and useful with age.

6.  Can be used with desktop or laptop PCs

PC Oscilloscopes are external devices that are connected to your PC using the ubiquitous Universal Serial Bus (USB). Virtually every laptop or desktop PC sold comes with multiple USB ports so there’s no problem using your PC Oscilloscope with either a desktop or a laptop PC.

7.  High-speed USB 3.0 connection

USB 3.0 can transfer data at speeds of up to 1 GS/s. Using powerful PC Oscilloscope software it give you incredible performance with fast screen updates and the ability to stream data.

8.  Hardware and software in one package

Choose PC Oscilloscopes that come complete with the hardware and software in one package.

9.  Use your PC Oscilloscope for data acquisition

Using the sw, you can transform your PC Oscilloscope into a data logger that can log data over extended periods of time.

10.  A complete test and measurement lab in one unit

When you buy a PC-based oscilloscope make sure you don’t just get an oscilloscope: make sure you also get a spectrum analyzer, meter and data logger rolled into your PC-Oscilloscope choice. Some models even include a built–in signal generator or arbitrary waveform generator. So with a PC Oscilloscope you really do get a complete test and measurement lab in one cost–effective unit.

NorthTree Associates is a distributor and supplier of Electronic Test & Measurement Equipment. Companies represented include ITIC USB 2.0 Protocol Analyzers, LabNation SmartScopes, Micsig Oscilloscopes, Oscium iOS Test Tools, OWON Oscilloscopes.

5 Features To Consider When Choosing A Digital Oscilloscope

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For anyone designing, manufacturing, or repairing electronic equipment, a digital storage oscilloscope is a must-have tool. It lets you see high-speed repetitive or single-shot signals across multiple channels to capture elusive glitches or transient events. An oscilloscope is equally as useful a tool for qualifying elements of a new design as it is for isolating problem components in an existing system under repair.
When it comes to evaluating oscilloscopes, many engineers focus on one specification: bandwidth. The assumption is generally that the faster oscilloscope is the better oscilloscope. And while bandwidth is an important thing to consider, it falls well short of telling the whole story or in ensuring that the oscilloscope you’re considering will truly meet your needs. With that in mind, here are five other things you’ll want to consider when choosing your next oscilloscope.

1. Rise time — Accurate rise-time measurements are key to making accurate measurements in the time domain. Many logic families have faster rise times (edge speeds) than their clock rates suggest. A processor with a 20 MHz clock may well have signals with rise times similar to those of an 800 MHz processor. Rise times are important for studying square waves and pulses. Square waves are standard for testing amplifier distortion and timing signals for TVs and computers. Pulses may represent glitches or information bits — too slow a rise time for the circuit being tested could shift the pulse in time and give a wrong value.

2. Fast sample rate — The sample rate of an oscilloscope is similar to the frame rate of a movie camera. It determines how much waveform detail the scope can capture. To capture glitches you need speed. A signal must be sampled at least twice as fast as its highest frequency component to accurately reconstruct it and avoid aliasing (showing artifacts that are not actually there). This is however an absolute minimum. What’s more, it applies only to sine waves and assumes a continuous signal. Glitches are by definition not continuous, and sampling at only twice the rate of the highest frequency component is usually not enough. A high sample rate increases resolution, ensuring that you’ll see intermittent events. As a rule of thumb, look for a sample rate of at least 5x your circuit’s highest frequency component.

3. Versatile triggering — All oscilloscopes provide edge triggering, and most offer pulse width triggering. But more advanced triggering capabilities can save you time and shorten the time to answer when working with more challenging signals. The wider the range of trigger options available, the more versatile the scope. Some of the triggers available include A & B sequence triggering; video triggering on line/frame/HD signals, etc.; logic triggers such as slew rate, glitch, pulse width, time-out, runt, setup-and-hold; and communications triggers for serial and parallel buses.

4. Powerful waveform navigation and analysis — Searching for specific waveform errors can be like searching for a needle in a haystack. Tools that automate the process can be a big time saver. For instance, oscilloscopes with record lengths in the millions of points can show thousands of screens worth of signal activity, essential for examining complex waveforms. Capabilities such as search and mark speed up the process by letting you search through the entire acquisition and automatically mark every occurrence of an event you specified. Other capabilities include zoom and pan, play and pause, and advanced search.

5. Matching probes — Precision measurements start at the probe tip. The probe’s bandwidth must match that of the oscilloscope, and must not overload the Device Under Test (DUT). Probes actually become a part of the circuit, introducing resistive, capacitive and inductive loading that alters the measurement. It’s important to have a range of probes available. To start with, select passive probes that have high bandwidth and low loading. Active ground-referenced probes offer one to four GHz bandwidth while active differential probes support 20 GHz or more. Adding a current probe enables the scope to calculate instantaneous power, true power, apparent power and phase. High voltage probes measure to 40kV peak. Specialty probes include logic, optical and environmental types.

Cost of ownership
Any scope you choose will need to fit within the constraints of a capital acquisition budget. While cost of ownership isn’t a feature per-se, it’s an important consideration.  This means you should compare support options to see to whether they add value to your purchase or can help extend the scope’s useful life. On-site education and training, as well as design, system integration, project management, and other professional services can help maximize productivity and ensure reliable measurements. Support packages such as these, along with options like extended warranty can save money in the long term.

Contact us with your questions or if you would like to visit our online store to shop for digital oscilloscopes – visit http://www.northtreeassociates.com / sales@northtreeassociates.com

NorthTree Associates Introduces OWON XDS Series Multi-Function Oscilloscopes

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The XDS series of oscilloscopes is the latest product release from OWON. With 12‐bit resolution, the XDS series offers the best solution for those who need to measure small signals or be able to read details from a large signal. Highly suitable for Medical, Automotive, Power Supply, and more.

In addition to having a 12‐bit resolution, the OWON XDS series of oscilloscopes are equipped with advanced technology and functions such as advanced trigger and decoding functions, Wi‐Fi and App support along with a capacitance touch screen.

OWON XDS series oscilloscopes come with the OWON 3rd generation technology platform ‐ Xvisual, which advances the performance of the XDS series oscilloscopes over other oscilloscopes available. The new Xvisual platform consists of 3 parts: Low Base Noise, 40M Record Length, 75,000 wfms/s Refresh Rate. One of the main benefits of Xvisual is ease at which the measurement of small signals can be read, and the ability to fully restore the true status of signals.

The XDS series oscilloscope software, provides advanced trigger and protocol decoding functions to help engineers analyze bus protocols and quick positioning. The embedded Wi‐Fi module ensures computers and cell phones can share the display screen to view and control the oscilloscope. Users can also check and save waveform data via App. By saving data via the App, data can be shared between other users.

The optional capacitance touch screen has been designed to look and act similar to a Smartphone – thus being intuitive and easy to start using right out of the box.

Additionally, the OWON XDS is complete mobile test station. It has incorporated the ultra‐thin design of the OWON SDS series oscilloscope, and has a battery option for portable use in the field. Besides the oscilloscope function, the OWON XDS also has function modules such as: a 25 MHz/50MHz single/dual channel(s) arbitrary waveform generator, a digital multimeter and a high precision data logger.

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor for OWON oscilloscopes, waveform generators, and programmable power supplies. NorthTree Associates provides unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers.

Micsig MS510S 2 Channel Handheld Oscilloscope Review

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The Micsig MS510S 2 Channel Handheld Multifunctional Oscilloscope is portable unit has two fully isolated 100MHz scope inputs, a built-in isolated multimeter, 14.5cm (5.7”) color touch-screen, up to 190k waveform updates per second, 240k points memory and a battery life of up to 7 hours. It’s supplied with a pair of isolated probes for measuring up to 600V (Cat II).

As portable scopes go, this handheld oscilloscope offering from Micsig has a lot of good features and reasonably priced. One of the reasons this review was written was that we recognized how useful it is to have a scope with two fully isolated channels; this makes it much easier to make measurements at two different points in a circuit which may not necessarily have the same ground reference.

However, you do have to be a bit careful using an isolated scope because you can possibly have a high voltage not only between the input signal and ground but between those grounds and from each ground to earth. So the probes and inputs need to be well-insulated to prevent accidental shocks.

The Micsig MS510S unit does not disappoint as it is supplied with two insulated probes that shroud the BNC connector shields, earth clips and test probes (to the extent possible). These are 500MHz, 10:1 types rated for 300V CAT III and 600V CAT II.

First impressions of the overall user interface are good. The screen has good contrast and color and is easy to read indoors; it has an outdoor color scheme which helps for reading in sunlight. However the lack of an anti-reflective coating on the display means it would work a lot better with a hood or under shade. The unit boots up fast – in just a couple of seconds – and responds to button presses pretty quickly. So it doesn’t feel sluggish to use.

While the touch-screen can be used to perform many functions such as moving along the timebase, moving traces up and down, zooming into portions of the waveform and selecting measurements to display, virtually all functions can also be performed using the front panel buttons and side jog wheel. The operation of this unit is quite different to most benchtop scopes but users will quickly figure out the controls and get used to them. Like most digital scopes, it has soft buttons (F1-F4) which drive the on-screen menus.

The control layout below these buttons is pretty simple and the function of most buttons is self-evident. This oscilloscope is 165mm wide, 255mm tall, 62mm deep (not including side carry strap) and weighs 1.7kg. It has a tilting stand at the back to prop it up on a flat surface. Supplied accessories include the two probes, a set of multimeter leads, mains charger, user manual and PC software on CD and warranty card.

Oscilloscope Functions

Each channel of the Micsig MS510S oscilloscope has a selectable sensitivity of 5mV-50V/division so with the supplied 10:1 probes, that gives a range of 50mV-500V per division. The sampling rate is 1GS/s with one channel active and 500MS/s with two. As stated earlier, storage is 240Kpoints total so with both channels active it can store 120K samples. Channel bandwidth can be restricted to 20MHz if required and each channel can be AC or DC coupled.

This oscilloscope uses a 9-bit ADC which is slightly better than bargain basement oscilloscopes (including desktop models) which typically use an 8-bit ADC. As such, when the bandwidth is set to 20MHz, the traces are quite clean, however there is still a fair bit of noise evident with 100MHz bandwidth (this setting affects both channels simultaneously). You can of course enable averaging to reduce noise with repetitive signals; this is also enabled for both channels at once. By default, the oscilloscope has trace persistence, which can be handy in some circumstances as it allows you to see the ‘spread’ of the signal, i.e. – to get an idea of jitter in a digital signal or amplitude stability in an analog signal.

But sometimes you want to turn it off to get a ‘cleaner’ looking trace – unfortunately, we can’t figure out how to do that with this unit. The minimum persistence setting is 100ms. This isn’t a huge problem but it does seem to be an oversight in the software. (As of this posting, Micsig is working on a solution for this issue).

You can display up to four measurements in oscilloscope mode, selected from a large list and these appear at the top of the screen, overlapping the graticule. They’re updated a couple of times a second. The unit also has basic X/Y cursors that can be enabled and moved around in the usual way. Typical trigger options are available, including Edge, Pulse, Logic (ie, high/high, high/low, etc), Video (including high definition) and Serial Bus. The hold-off time is adjustable as is the trigger coupling (AC/DC).

Serial Bus Decoding

While this is not a mixed signal oscilloscope, it does have an option to decode various serial buses and trigger on the contents of the packets. This includes serial, LIN, CAN, SPI and I2C although given the fact that there are only two channels, it’s more suitable for I2C than say SPI.

Multimeter Functions

The built-in multimeter of the Micsig MS510S is easy to use because of the large touch-screen. It’s easy to switch modes by pressing on their icons and the numeric display is large. One aspect we particularly like is that it auto-ranges almost instantly, which overcomes one of the biggest arguments against auto-ranging meters (which, let’s face it, are pretty much standard now).

However, there is one major drawback apart from the modest 4-digit resolution and that is that you need an external accessory to do current measurements – either a shunt or a hall-effect sensor (clamp meter). These are available as accessories; however Micsig does not currently list them or have a price. So that probably means you need a multimeter on hand, in addition to the Micsig MS510S. But that’s not to say the multimeter functions are useless – far from it.

It offers DC and AC voltage in ranges such as 500mV, 5V, 50V along with a maximum of 1000V DC and 750V AC (20kHz bandwidth). The multimeter inputs are fully isolated from the scope inputs. It also does statistics (minimum/average/maximum) and has a bar graph in addition to the numerical read-out.

Other modes include resistance (0-50MΩ), continuity (50Ω threshold), diode test (up to 3.5V), capacitance 100pF-50ΩF), temperature and humidity (requiring an external sensor accessory) and pressure (also requiring an external sensor accessory).

One nice feature of the Micsig MS510S oscilloscope is that the multimeter inputs can also double as calibration outputs for the probes. Small adaptors are supplied to make the connections.

Data Logging

The Micsig MS510S also has a “Recorder” mode where it can log readings from either the meter or oscilloscope input(s). When logging from the meter, you can choose from DC volts, AC volts or DC+AC volts. You can also log DC amps, AC amps, temperature, humidity and pressure but all these extra modes require the appropriate accessory.

The readings are displayed in an automatically-scaled horizontally scrolling chart format and the data can then be saved to a USB flash drive (in an “.MMR” file format) or in a screen grab of the chart. It can be set to either stop storing data when full, or set to a circular buffer mode where it overwrites the earliest data with later data once storage space is exhausted.

For data logging from the oscilloscope input(s), it can either log a low-frequency view of the two input channels or alternatively, it can log one or two of the scope measurements. In the latter case, you need to first enable the measurements you require on the appropriate channels, then about five hours to reach full charge.

Conclusion

As portable oscilloscopes go, the Micsig MS510S is a pretty attractive proposition. Even for bench-top use, the dual isolated channels and ability to easily move it around are quite useful features. While we would like to see a couple of software tweaks and an anti-glare coating on the screen, it’s a very flexible instrument with good overall performance and a responsive user interface.

While the Micsig MS510S is not light, it can be operated hand-held and with the protective rubber surround, appears to be robust enough for field use.

For applications where performance is not so critical, the Micsig MS-310IT oscilloscope is a more economical option. The main difference is the waveform update rate – the Micsig MS510S has 190K samples/second and the Micsig MS310IT only has 50Ksamples/second. Micsig also has the MS-200T series oscilloscopes are even more economical, but as with the MS310IT oscilloscope, this series does not feature isolated inputs.

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor that provides unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers.