10 Features of The OWON XDS Series Oscilloscope Will Help You Build The Oscilloscope You Need

Front

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.

Here are 10 Reasons Why The OWON XDS Series Oscilloscope Will Be Your Next Oscilloscope:

  1. Large Touch Screen

OWON XDS Oscilloscopes have a generous 8 inch, 800×600 pixels resolution capacitance multi-point touch screen. The operation patterns are the same as the mobile version. Most other oscilloscopes on the market are using a resistance screen, which isn’t as user-friendly in this era of touch screen gadgets and tools.

  1. Signal Generator Module

The XDS Series Oscilloscopes has the option of 25MHz arbitrary waveform signal generator – in a single or dual channel option. When using the dual channel option, each channel is totally isolated. With the 8-bit models (XDS3102/XDS3202) a user has the additional option of choosing 50MHz signal generator.

  1. Multimeter Module

With a 4000 count multimeter module option, the OWON XDS Oscilloscope is not like other oscilloscopes which have simple voltage measurement function multimeters. The XDS Oscilloscope employs a real multimeter module. It has the capabilities to measure the voltage, current, resistance, and capacitance of a signal(s).

  1. 12-bits vertical resolution

OWON XDS Oscilloscopes use 12-bit hardware ADC. When an 8-bit ADC oscilloscope extends its waveform to a more detailed shape, the shape will become distorted. This is caused by quantizing noise. When using a 12-bit unit, distortion does not occur. The XDS Oscilloscope with 12-bits ADC has 16 times the vertical resolution than an 8-bit oscilloscope. Thus, a smaller signal can be viewed more clearly.

  1. Communications Interface

XDS Series Oscilloscopes have USB, LAN, VGA, AV and Wi-Fi interfaces for communication.

OWON has introduced its Wi-Fi Module with the release of the XDS Series Oscilloscopes. The Wi-Fi Module has 2 modes: Wi-Fi AP and Wi-Fi STA. Wi-Fi AP is to make the oscilloscope act as a hot spot. A user can use a mobile device or computer to connect to the oscilloscope. This will allow a user to access and use the software inside a mobile device/computer to control and monitor the oscilloscope. When the oscilloscope is set to Wi-Fi STA, it allows the oscilloscope to connect with a router, making it accessible on the same local area network as a user’s computer. In this situation, one computer can control and have access to multiple oscilloscopes at the same time.

  1. Battery

The XDS has the option to purchase a battery to make it portable in use. It contains 13200mA power, which lasts about 4 hours. Easy to install and remove. The float measurement is possible continuously supported while the unit is being powered by the battery. It also prevents the channels from ground disturbance(s).

  1. Low Base Noise

The Base Noise of the OWON XDS is extremely low. When it is at 1mV/div position, the base noise is only 50μV or so. The lower the base noise, the better and more accurately a small signal is represented.

  1. Deep Record Length

With an extremely deep 40M record length, the XDS Oscilloscope can capture more data one time than most other oscilloscopes on the market.

  1. High Waveform Refresh Rate

With a fast 75,000 wfms/s high waveform refresh rate, the OWON XDS Oscilloscope easily captures abnormal signals or rare events.

  1. Data Logger

The XDS Oscilloscope comes with 1ppm frequency stability to make it more accurate in data logging. Other oscilloscopes on the market only come with a 50ppm or 100ppm capability reading.

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 a 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. www.northtreeassociates.com

NorthTree Associates Announces New OWON AG-S Series Waveform Generators

OWON AG-S Series Waveform Generator

NorthTree Associates introduces the economical OWON AG-S Series of Waveform Generators. These versatile waveform generators from OWON derive both function and arbitrary waveforms using Direct Digital Synthesis (DDS) technology.

In using Direct Digital Synthesis (DDS) technology, the new OWON AG-S Series Waveform Generators provide stable, precise, low-distortion signals from DC up to 150MHz, (depending upon model);  all with 14-bit vertical resolution. Included are standard functions (sine, square, pulse, and ramp), a noise output and a number of built-in arbitrary waveforms.  The Z out is adjustable from 50 Omega to ‘Hi-Z’, and in Hi-Z mode can output in excess of 20Vp-p; therefore a 7.07Vrms waveform can be achieved with plenty of adjustment headroom.

OWON designed the AG-S Series Waveform Generators with a user-friendly panel layout featuring a 3.9” TFT color LCD (480 x 320), the menu-driven controls are flexible and intuitive – all functions and parameters are within easy access, allowing users to quickly and easily produce the test signals they need. A useful integrated Help function shows descriptions of single functions and step-by-step instructions for operational tasks.

The AC low-frequency limit is 1μHz on all models; on all models except the AG4151 the lowest output level is 1mVp-p.  The frequency control on these units is good; for example, the AG1012 shows a ‘typical’ SSB phase noise of -100dBc/Hz at 10kHz offset (running at 10MHz). Also, depending upon the model, there are various I/O features available on the rear panel, but all include RS232 and USB (Host and Device); PC control via SCPI commands is supported for remote setting of the instrument’s parameters and output, and the PC’s display can synchronously reproduce the waveform generator’s screen image.

In addition to representing the OWON AG-S Series Waveform Generators, NorthTree Associates also represents other product lines from OWON. These product lines include the customizable XDS Series Multi-Function Oscilloscopes, MSO Series Mixed Signal Oscilloscopes, HDS Series Handheld Oscilloscopes, Multimeters, and DC Power Supplies.

Established in 1990, OWON is based in China, specializing in the manufacture of oscilloscopes, waveform generators, multimeters, and programmable DC power supplies. These capable instruments are distributed to customers in the aerospace, automotive, communication, defense, electrical, and education industries in more than 80 countries across the globe.

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. www.northtreeassociates.com

OWON XDS Series Oscilloscope Tech Review

Front

“Base Noise: The Oscilloscope Parameter Often Ignored.”

When it comes to the main parameters of oscilloscopes, bandwidth, sample rate, and recording length all come to mind. However, there is a parameter that is often ignored: Base Noise.

What is the Base Noise? Why it is so important? The following will explain what it is and why it shouldn’t be overlooked.

Base Noise refers to the “Baseline Noise”, which indicates the vertical noise in the transformation of a simulated front end and a digital end.

As an example, OWON looked at The Base Noise of an oscilloscope. In particular, we looked at the noise a waveform generated while the OWON oscilloscope was turning into its most sensitive vertical position. The range scale of Base Noise was determined by counting the SNR (Signal to Noise Ratio). The higher the value, the lower the interference. Thus, the lower Base Noise the signal contained.

How Base Noise influences measurement results:

With the rapid development and advancement of electronics technology, some processing chips are limited in their ability to generate mVs in power. The power ripple might be required at ±5% or even lower. If the Base Noise is very high, the real measured signal would be drowned in the Base Noise of the device, and engineers would then get a false reading. Therefore, Base Noise is very important when measuring small signals.

Since the Base Noise is so important. Why don’t oscilloscope manufacturers mention this?

The main reason: cost control. Most of middle to low end oscilloscopes in the market are designed for larger bandwidth or higher sample rate. Their processor chips are mostly used for overclock running, which causes the other components to overload while running. This then contributes to a large Base Noise effect. Oscilloscope manufacturers are not willing to expose their shortcoming, so a user is unable to learn of a particular oscilloscope brand’s Base Noise until put to use for their application.

OWON conducted a comparison of the Base Noise level of popular oscilloscope on market:

OWON - T

T Company’s oscilloscope on 1mV/div and 500us position.

(440uV Peak-Peak Voltage)

OWON - R

R brand popular oscilloscope on 1mV/div and 500us position.

(920uV Peak-Peak Voltage)

OWON - C

A Chinese brand 3000 series oscilloscope on 1mV/div and 500us position.

(467uV Peak-Peak Voltage)

OWON - O

Lilliput OWON XDS Series Oscilloscope on 1mV/div and 500us position. (380uV Peak-Peak Voltage)

Based on the oscilloscope comparison, most of middle end oscilloscopes had more than 500uV noise. The brand that consistently had the lowest Base Noise was the OWON XDS Series Oscilloscope. Their VPP value held on an average of 350uV. The OWON XDS Series Oscilloscope controlled Base Noise better than T Company’s most popular mid-range oscilloscope.

The OWON XDS Series Oscilloscope 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.

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.

If you need an economical oscilloscope to measure small signals, the OWON XDS Series Oscilloscopes are your best choice.

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. www.northtreeassociates.com

The Basics of Measuring Visible Light – A Primer on Photometry Tools

HT309_sito

The Basics of Measuring Visible Light – A Primer on Photometry Tools

Radiometric Description

Radiometry is a broad field encompassing all techniques for measuring electromagnetic radiation, including the measure of visible light. These techniques measure the distribution of the radiation’s power in space. This field includes photometry, which more specifically measures attributes of electromagnetic energy that are visible to the human eye. Instruments in this category address both the broad and more specific attributes of light these fields cover.

LED Analyzer

LED Analyzers measure the luminous flux of LED lights. This means that the unit measures the total visible energy emitted by a light source. Typically, these incorporate a sphere in which the light source to be measured is placed; the sphere focuses all the power emitted from the light source directly on the detection component. Gigahertz-Optik offers analyzers with a range of different sphere sizes to meet any need.

Light -1Light Meters / Illuminance Meters

An Illuminance Meter measures how much a given incident light illuminates a surface, unlike a luminance meter, which measures the light being emitted from a particular area. Many illuminance meters do also function as luminance meters given they use certain attachments.

Illuminance is basically another word for brightness. However the term brightness should not be used for quantitative description. Therefore we say illuminance. Today illuminance meters can effectively measure most types of visible light.

Light - 2
Key Features of Light Meters / Illuminance Meters

  • Measuring Modes. Some meters can measure Illuminance, illuminance difference, average illuminance, illuminance ratio, integrated illuminance, and integration time. Most other meters can measure in a maximum of five modes and many often require special attachments to measure in certain modes.
  • Accuracy Classification. Meters are classified by DIN and JIS standards.
    • DIN classes: L, A, B, C
    • JIN classes: Precision, AA, A, B

Class L and Precision are the highest classes in each, respectively. A higher class translates to greater accuracy. However, it will also mean a higher price.

  • Illuminance Range. Most meters typically have a maximum range of 199,900 lx

Luminance Meters

Luminance is a photometric measurement of the luminous intensity of light travelling in a given direction. In other words, it describes the amount of light that passes through or is emitted from a particular area at a particular solid angle. This type of measurement is especially useful because it quantifies the properties of light that the human eye actually perceives. Measuring these quantities of light is essential, for example, for TV studios, sports arenas, emergency situation lighting, traffic lighting, and automobile lighting.
Light - 3

Light - 4Key Features of Luminance Meters

  • Measuring Method. Luminance meters can measure either with contact or from a distance. Many can perform both, but some can only do one or the other, so choose wisely based on your needs.
  • Measuring Modes. Luminance meters can measure several attributes of luminance. Typically units can measure luminance, luminance ratio, and peak luminance/luminance ratio. However, some units can measure more than just these attributes.
  • Luminance Range. This is simply the range of values a luminance meter can measure. This range differs depending on measuring angle.

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. www.northtreeassociates.com

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.

Pic 6

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

9 Factors to Consider When Choosing an Oscilloscope

SDS Front

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

NorthTree Associates Announces Micsig Sales Promotion On TO202 and TO202A tBook Tablet Oscilloscopes

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A new Micsig sales promotion is underway at NorthTree Associates. The Micsig TO202 and TO202A  tBook Tablet Oscilloscope have been put on sale at special prices.

The Micsig TO 202 tBook Tablet Oscilloscope has 2 channels, a 200MHz bandwidth, and a 1GSs sampling rate is now priced at $669.00. CLICK HERE NOW to order and see complete specifications.

In addition, the MicsigTO202A tBook Tablet Oscilloscope has 2 channels, 200MHz bandwidth, and a 2GSs sampling rate is now priced at $769.00. CLICK HERE NOW to order and see complete specifications.

As the tBook Tablet Oscilloscope innovator, Micsig has achieved various worldwide patent rights, software copyright for their touch screen tBook Tablet Oscilloscope. Features include: a multi-touch screen, 100MHz to 200MHz bandwidth, 2 or 4 channels, real time sampling rates of 1GS/s to 2GS/s, compact design, high memory depths, and excellent function features.

The affordably priced Micsig handheld oscilloscopes offer bandwidths ranging from 70MHz up to 200MHz, two channels and 1GS/s sampling rate, making them deal for both laboratory testing and field service applications across a wide range of industry sectors.

High performance features offered by Micsig oscilloscopes include isolated inputs for safely carrying out floating measurements, up to 190,000 wfms/s refresh rate, support for serial bus protocol trigger and decode (1553B/429/UART/232/485/LIN/CAN/SPI/12C) in both graphic and text modes, and multi-function operation including digital oscilloscope, digital multimeter and recorder.

In oscilloscope mode, the units offer a wide range of trigger types, 31 automatic measurements, and maths functions including FFT. Isolated input versions offer up to 1000V CAT II 600V CAT III maximum channel floating voltage.

Designed for user-friendly operation with Micsig’s touch screen technology, the oscilloscope offers three operation modes – moving the waveform, zooming in and out, and menu option selection – with the large 5.7 inch TFT LCD screen providing users with a sharp 640 x 480 high resolution display. A user selectable indoor (black background) or outdoor (white background) display mode makes the models particularly useful in field service applications.

The Li-ion batteries provide users with up to 6 hours of continuous operation, while the USB host and slave interface allows users to easily download captured waveforms as well as connect the oscilloscopes to a PC.

NorthTree Associates based in Cologne, MN provides unique Electronic Test & Measurement tools for increasing productivity. You can reach NorthTree Associates at sales@northtreeassociates.com