Fullscreen HTML5Med Res (??MB)HTML4

Review by Tim Blythman RIGOL MSO5354 Mixed Signal Oscilloscope The MSO5000 series is the latest range of mixed-signal oscilloscopes from Rigol. They were released a few months after the high-end MSO7000 series. Emona Instruments lent us a top-of-the-range MSO5354 with all options installed for review. The entry-level scope in this series, the MSO5072, starts at around $1500 and can be upgraded later with more channels or bandwidth as needed. T he MSO5000 series is based around a custom ASIC (application specific integrated circuit), the Phoenix Oscilloscope ASIC chipset, which allows for sampling rates of up to 8GS/s and waveform capture rates of up to 500,000/sec. It also supports enough memory to store one hundred million samples, although this scope can be upgraded to 200Mpoints of memory. The large sample capacity of up to 200Mpoints is important since it means that more data is available for analysis via methods such as FFT (fast Fourier transform) spectral 30 Silicon Chip analysis. It also allows the user to zoom and pan through a long period of captured data, while still retaining fine details of the waveform. The models in the MSO5000 range vary from two channels with 70MHz bandwidth (MSO5072) all the way up to the four channel model with 350MHz bandwidth (MSO5354) that we’re reviewing. Since the MSO5072 can be upgraded to have the same features as the MSO5354, the internal hardware is essentially the same for all models within the series and the upgrades simply allow more features to be used. Australia’s electronics magazine siliconchip.com.au While this is useful in that you can choose features according to your available budget and still have the option to upgrade the difference later, we wonder if it will not be long until someone succeeds in upgrading their MSO5072 without purchasing the official upgrade option. If you’re not sure what capabilities you need, you can simply purchase an MSO5072 and then if you run into a situation where it isn’t up to the job, upgrade it as needed. So you aren’t paying for extra capability at the start that you may or may not need in future. Additional software options available on all scopes in the MSO5000 series are up to six serial protocol analysers, twin 25MHz arbitrary waveform generators and power analysis software. Our sample unit included all these options, which would otherwise need to be purchased separately or as a bundle. There is a large socket under the sizeable (9-inch, 1024x600 pixel) display which accepts an IDC header, which is the connection point for the 16-channel digital logic analyser. Utilising these digital inputs requires a separate, optional set of logic analyser cable and probes. By the way, besides its performance, the large colour display is a good reason to consider purchasing an MSO5000series scope rather than one of its smaller cousins. First impressions Features & Specifications • 9-inch LCD touchscreen display with 1024 x 600 pixel resolution • 2 or 4 analog channels • 16 digital channels (requires optional Active Logic Probe, not included) • 2 arbitrary waveform generator outputs (25MHz/200MSa/s) • Communications interfaces: USB Host (GPIB), USB Device (eg, flash drive), Ethernet, HDM • Bandwidth: 70MHz, 100MHz, 200MHz or 350MHz* • Sampling system: 8-bit, 8GSa/s (shared between all channels) • Sample memory: 100 million points, upgradeable to 200 million points • Waveform capture rate: 500,000 waveforms per second • Serial decoders: RS232/UART, I2C, SPI, CAN, LIN, I2S, FlexRay, MILSTD-155 • Other analysis modes: Histogram, Math x 4, FFT, Digital Voltmeter, Frequency Counter, Power Analysis   * Depends on model, all upgradeable And just like many portable devices, gestures such as pinch, zoom and swipe can be used to scale and shift the traces in the main display. We found this wasn’t very snappy, and were comfortable with dialling these in via the conventional rotary encoders. You are not forced to use the touchscreen on this scope as all functions can be activated using the traditional button-and-knob controls if desired. You can even temporarily disable the touchscreen function if you want to – an excellent way to keep finger grease off the LCD! Having some experience using other scopes, we had no trouble getting a trace on the screen and setting the controls to make it stable. The “Measure” button allowed us to quickly bring up a display showing such characteristics as frequency, period and peak-to-peak voltage. We noticed a bit more fan noise from the unit during operation than we would expect but it isn’t overly loud. The most striking thing about the scope when you first see it is that it has a black case. We didn’t mind this in general, except for the fact that the small number of embossed markings on the features below the screen were less legible than they might have been with a white or beige case. When turning the unit on, it takes about a minute to boot into a usable scope screen, which is much longer than we’d like. There’s a progress bar at the bottom of the screen which moves smoothly left-to-right but you still have to wait about 15 seconds after it reaches the right-hand end before you can use the scope. Once booted, the display is uncluttered, with small onscreen buttons visible above and below the main graticule. The displays along the top of the screen to the horizon- Useful features tal timebase and trigger levels are actually active parts of There are over 40 basic measurements possible on each a touchscreen, and can be pressed to edit these values di- waveform – Fig.1 shows just those relating to time (rather rectly. than voltage or curWe are seeing more rent). and more scopes The best thing about with touchscreens, the measurements, although the ones though, is that you we use day-to-day can select ten different in the office do not measurements that can have touchscreens. all be displayed simulIt didn’t take long to taneously along the get into the habit of bottom of the screen. using the on-screen Compared to the four controls, if for no that many older scopes other reason than can show, this is a it is more intuitive revelation. You idealthan using a rotary ly want at least eight encoder to navigate measurements with a the various menus. four-channel scope (eg, And like most new- On the back of the scope are connections for HDMI, USB-B (to connect to a frequency and amplier scopes there are computer), Ethernet and a BNC socket marked ‘TRIG OUT’, as well as mains tude for each channel) many options avail- power. The TRIG OUT socket can generate a pulse on each trigger event or and having two more able to navigate. spare is fantastic. can signal the results of the pass/fail test. siliconchip.com.au Australia’s electronics magazine February 2019  31 Fig.1: the Measure button gives access to over 40 trace measurements that can be displayed (up to ten at a time) along the bottom of the screen. The Horizontal tab gives access to time-based measurements, while the Vertical tab gives voltage measurements such as peak-to-peak, RMS, average and even overshoot. Fig.2: the Function Navigation button in the bottomleft corner opens the menu for more advanced analysis functions and settings including FFT, mathematical calculations, power analysis and digital signal decoding. Power analysis and digital signal decoding require an optional add-on software to be applied to base-level scopes. Another significant aspect of the measurements on this scope is that you can choose whether the scope uses the traces that are visible on-screen to calculate the readings, or it can use its entire memory. For example, if you are using min/max voltage measurements, you may want it to use trace data that is not immediately visible. On that theme of being able to show a lot of useful stuff on the screen at once, this scope can also display four “math” traces at once (FOUR!). That’s way better than the single trace that many other scopes (some very expensive) can show. There are definitely times in the past when we would have loved to have that feature. This scope has a wide range of triggering options, including Edge, Pulse, Slope, Video, Pattern, Duration, Timeout, Runt, Window, Delay, Setup/Hold, Nth Edge and Serial. Many other scopes do not have options like Runt (used to find occasional short pulses) or Window, which triggers when the trace passes through a rectangle that you can drag on the touchscreen. Like most other scopes, this one uses an 8-bit analog-todigital converter (ADC). That does not give quite as good vertical resolution as a scope with a 10-bit ADC. But one of the selling points of Rigol scopes is that their front ends are usually low-noise types, allowing you to still monitor quite low-level signals without them getting “lost in the noise”. While we don’t think this scope is quite as good as some of Rigol’s other scopes in that respect, it does have a 1mV/ div maximum vertical sensitivity which is pretty good, and the noise level still seems quite low, so it should be quite good at probing low-level analog signals. The noise level is around 1.25mV peak-to-peak/250µV RMS with 20MHz bandwidth limiting, rising to about 2mV peak-to-peak/400µV RMS with the full 350MHz bandwidth – see Fig.8. Regarding serial decoding and triggering, once again the MSO5000 series is quite generous in allowing you to decode up to four serial buses at once, while optionally triggering off one of them (eg, on a value match). You can see an example of serial decoding in Fig.7. The optional power analysis software is useful for those working with switchmode power supplies and similar devices. With appropriate probes connected to the right points in the circuit, it can calculate information such as power quality, efficiency, power factor, crest factor and do ripple analysis. Function Navigation button The scope has a button in the bottom-left corner of the screen, called the “Function Navigation” button (Fig.2), which gives access to more options from a simple on-screen digital voltmeter through to FFTs (Fig.6) and signal decoding. The list includes a pass/fail tool, which can be used to create tests similar to eye tests. Fig.3: the web interface is easy to access via the scope’s IP address from a web browser, and provides control of most of the scope’s features as well as showing what’s on the screen. 32 Silicon Chip Australia’s electronics magazine siliconchip.com.au Fig.4: the display persistence setting allows signal jitter to be more clearly seen than on many other scopes. The amount of shift from the trigger point is visible over many cycles. It’s also helpful for getting an idea of amplitude modulation/instability, runt pulses and other phenomena. Fig.5: one minor disadvantage of the persistence setting is the tendency to completely obscure other waveforms. In this case, the cyan waveform is almost completely hidden where it overlaps. The traces need to be shifted up or down so they don’t overlap if you are to see all their details. To use this feature, you set up an envelope; the easiest way to do so is to input a ‘passing’ signal and allow the scope to create the envelope around it. The pass/fail tool can then quickly indicate whether a probed signal is within expected limits or not. socket marked ‘TRIG OUT’. Typically, screen grabs are made by inserting a USB flash drive into the USB Type-A socket on the front of the unit and saving the screenshot as a file on the flash drive. While this is possible on the MSO5354, the aforementioned sockets make other options available. We found the easiest way to get our scope grabs was to connect an Ethernet cable. By default, DHCP is enabled and so the scope is automatically allocated an IP address. After entering the IP address in our browser, we were able not just to view the scope screen and save images, but we could control most of the functions as though we were touching the touchscreen. Many of the hardware buttons are mapped to a column of extra buttons on the web page view of the scope screen (see Fig.3). Such a setup is great if you have any need to access the scope remotely for any reason, and although a bit slow at times, the browser approach provided access to practically all the scope’s functions. It even supports devices like phones and tablets – as long as they are on the same network and have a decent browser, it should work. It appears the unit can also print to a network printer and Basic controls Probe settings are found by simply pressing the corresponding channel button. This lets you select the coupling mode (AC/DC), bandwidth limit (off/20MHz/100MHz/200MHz) and probe attenuation, over a wide range of values from 0.01 times to 50000 times. While the MSO5354 does not have automatic probe sensing, you only really need to change the attenuation setting when changing probes. If you forget to set the attenuation and capture some data, you can still change it as the display adapts automatically to the new settings. Connectivity We were curious about the various connections that are available on the back of the scope. It features HDMI, USB (a type-B socket) and Ethernet connections, as well as a BNC Fig.6: we connected an AM loop antenna to the scope’s input and set it up to run an FFT from 500kHz to 2000kHz, covering the AM broadcast band. This display was updating around once per second, and although the peak at 1.25MHz under the cursor did not appear to correspond to a broadcast station on an AM radio, the next one to the left matched well with a strong signal at around 1218kHz. siliconchip.com.au Fig.7: the serial decoding tool is an optional extra, and can be applied to any of the four analog inputs or the 16 digital inputs if the Logic Analyser add-on is fitted. Here, a 115.2kHz square wave is being correctly decoded as valid 230,400 baud serial data, as bytes of 0x55 hexadecimal. Australia’s electronics magazine February 2019  33 We could see how having two separate channels could come in useful. You may want to use one channel to generate a clock signal and another to inject a test signal elsewhere in the circuit, for example. The AWG in this scope can generate sinewaves up to 25MHz (at 200MSa/s), which is a little bit higher than some other scopes we have used (they topped out at 20MHz). Of course, other waveforms like square and triangle cannot be produced at the full 25MHz as there would be too much rounding. Square waves up to 15MHz are possible. The AWG has other nice features such as modulation, sweep and signal burst options. Fig.8: feeding a 5mV, 1kHz signal into the scope shows how it handles low-level signals. Bandwidth limiting was enabled for this test (20MHz). Some of the noise would be from the signal source and/or RF pickup in the probe. Also note the full complement of ten quick measurements along the bottom of the screen. send emails with the scope’s screenshots attached, although we did not have the time to try any of these features. You can also download and install the dedicated “Ultra Sigma” application to your PC, which can control the scope via USB, Ethernet or GPIB. But the web interface is adequate for many jobs, even if somewhat laggy. If you need a better display of the scope’s screen, the HDMI interface would be ideal. It merely needs to be turned on via the Utility->IO->HDMI menu. The screen resolution used is 1280 x 720, with the 1024 x 600 pixel scope display centred on the monitor. Persistence One feature that we found handy is the persistence setting. This allows previous sweeps of the trace to remain on the screen for a while. The traces appear to fade slowly, just as an analog scope raster would. When viewing traces that are unstable or have jitter, the persistence helps to indicate the nature of the instabilities. Many cheaper scopes have persistence but it’s often unusable – a gimmick, essentially. On a scope like this, with a proper ASIC behind it, it’s an entirely different proposition. A less capable scope will tend to render traces as a solid mass of trace colour (more or less). It can be difficult to tell how the jitter is spread, or how the waveform varies from cycle to cycle in other ways, such as amplitude variation, because all traces are pretty much the same intensity. On the MSO5354, the trace is reinforced in places where it lands consistently, and appears darker when it lands sporadically in other parts of the graticule (see Fig.4). While this works well with a single trace, when multiple traces overlap, they do not undergo any alpha blending, so that a second trace can be swamped entirely in places by a faint pass of the first trace (see Fig.5). Since the second trace would be swamped in such cases on other scopes, this is a minor complaint, and you can always separate them if it becomes a major problem. But it would be a nice refinement to incorporate some alpha blending between different traces. Waveform generator One of the features we haven’t seen before on any scope is the inclusion of a dual arbitrary waveform generator (AWG). 34 Silicon Chip Quick button There is a button marked “quick” to the right of the display, and by default, it is programmed to save a .png screenshot to an inserted USB flash drive. But it can be programmed for other jobs such as to reset the measurement statistics, start recording, or a number of other actions. We find the default action quite useful as making screen grabs is something we need to do frequently. On the bench The unit has a fold-up handle and fold-down feet. The handle is firmly recessed, taking a surprising amount of force to raise. The collapsible feet under the unit allow the scope to be raked back slightly when sitting on a flat surface. It doesn’t actually change the angle much, and the feet tend to fold up (suddenly) if the scope is tilted forward, such as if you are plugging something into the rear. Otherwise, the unit is quite compact, if somewhat heavy for its size. We found the screen pleasant to look at. Although there are settings to adjust trace intensity and graticule brightness, the various other display elements do not appear to be adjustable. Conclusion With digital protocols appearing in more projects, we would have like to see the Logic Analyser function and serial decoding included, as adding these to the base MSO5072 scope doubles its price. Having said that, users who are mostly working with analog circuitry may not see the benefits. While there is the opportunity to start with a lower-end unit and upgrade as needed, the pricing structure does make it better value to purchase the higher bandwidths from the start. We found the MSO5354 straightforward to use and found that it was able to do anything that we would have asked of it, and would definitely consider it if ever needed to upgrade one of our existing scopes. We should mention that we ran into a few user interface glitches while testing this scope out, eg, times when the touchscreen would not respond to press but the buttons still worked. But it is a pre-production unit and Emona warned us that it would be a bit buggy. They assured us that production models would not have these problems (and maybe the boot-up time will be faster; surely, one can hope...) Where from, how much: Rigol ’scopes are distributed in Australia by Emona Instruments Pty Ltd (www.emona.com.au; tel 1800 632 593). The top-of-the-range Rigol MSO5354 (as reviewed) retails for $6452.60 inc. GST; the entry-level model in the range, the MSO5072 retails for $1479.50 inc. GST SC Australia’s electronics magazine siliconchip.com.au