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Rigol DS5062 digital Rigol Technologies Inc, based in Beijing, China, manufactures a range of digital storage oscilloscopes, including the DS5062MA, a dual-channel DSO with a bandwidth of 60MHz and real time sampling rate up to 1Gsa/s. Other DSOs in the series have bandwidths up to 200MHz. The bandwidth can be reduced from 60MHz down to 20MHz to increase accuracy and reduce displayed noise, if required. This particular model features a monochrome “¼ VGA” LCD screen (320x240 pixels) and has a memory depth of 4K samples per channel. The display refresh rate is over 1kHz. The DS5062MA is supplied with two passive probes with switchable x10 attenuation, although it accepts probes with attenuations up to x1000. Inputs are rated at 400V maximum. Running through the spec sheet reveals selectable input impedances of 50W (useful for RF measurements) and 1MW for almost everything else. Fig.1: an AC-coupled sine wave and square wave at approximately 95.5kHz. The frequency counter is shown at top right. Three measurements are displayed on the bottom line: RMS voltage of both channels and the positive duty of the square wave. 84  Silicon Chip Fig.2: a square wave at approximately 95.5kHz, shown in the top half of the display and the Fourier Transform with peaks at the odd harmonics is shown below. In the top-right corner, you can see the frequency as well as the values of the two horizontal cursors, the difference between them and the frequency equivalent. siliconchip.com.au 2MA 60MHz 1GS/s storage oscilloscope It has 8-bit vertical resolution. There are 10 voltage and 10 time/frequency measurements, of which any three can be displayed at the bottom of the screen. The voltage measurements include maximum, minimum, peak-to-peak, RMS, average and over-shoot and pre-shoot values (the latter as percentages). Time domain measurements include frequency, period, rise time, fall time and positive and negative duty periods. You can also display all 20 measurements at the touch of a button but this reduces the active screen area for the traces. In addition, the signal frequency is displayed in the top righthand corner of the screen and you do not have to display a complete signal cycle for it to give a meaningful reading. Two cursors are provided in three different modes of operation: automatic, manual (vertical or horizontal) and tracking. The latter mode gives an X and Y Review by Mauro Grassi cursor and the intersection of these can show the X and Y coordinates of any point on the waveform. The DS5062MA can acquire average values (up to 256 values can be averaged) and detect peaks of the input waveform. The averaging feature, as well as the digital filter (providing low, high, band-pass and band-stop programmable filters) is particularly handy when working with noisy signals. A nice feature is the so-called “analog acquisition”, where the DSO calculates the probabilities of pixels being on or off and varies the intensity accordingly to mimic an analog display. When sampling at less than the Nyquist requirement an anti-aliasing feature is provided. The DS5062MA has a surprisingly easy-to-use and intuitive pass/fail test feature. This allows for an error Fig.3: this is a PAL video test signal (eight colour bars) from the “Pocket AV Generator” featured in the June 2006 issue. The trigger mode is set to video and PAL is selected. The frequency counter shows 16.020kHz (actually 15.625kHz), the horizontal frequency. The sync pulse and the colour burst can be easily seen. The bottom half is an expanded display of the colour burst sequence. siliconchip.com.au in the X and Y axes to be set and user rules to be defined. A mask is created, shown visually on the display in grey and when the test is commenced, any signal points that intersect with it trigger a user-programmable fail or pass response from the DSO. The “MATH” feature allows the two channels to be combined in any of the four arithmetic relationships (add, subtract, multiply and divide) as well as giving an on-screen FFT (Fast Fourier Transform) with four modes: Rectangular, Hamming, Hanning and Blackman. The FFT can be displayed below the waveform in a split-screen arrangement or superimposed on the waveform in full-screen mode. On-screen menus are accessed via five function keys to the right of the screen. These menus can be cleared from the screen by pressing the Off button or they can be set to slide off the screen after a delay (exit right!). A convenient “AUTO” button configures the DSO to display the input waveform in a couple of seconds – Fig.4:this screen grab shows channel 1 at top (a sine wave at around 95.5 kHz) superimposed with the maths function output of A-B where A is channel 1 and B is a square wave at the same frequency and phase. The lower trace shows the result of zooming in on the unshaded area in the top display. August 2007  85 JOIN THE TECHNOLOGY AGE NOW with PICAXE Developed as a teaching tool, the PICAXE is a low-cost “brain” for almost any project Easy to use and understand, professionals & hobbyists can be productive within minutes. Free software development system and low-cost in-circuit programming. Variety of hardware, project boards and kits to suit your application. Digital, analog, RS232, 1-Wire™, SPI and I2C. PC connectivity. Applications include: Datalogging Robotics Measurement & instruments Motor & lighting control Farming & agriculture Internet server Wireless links Colour sensing Fun games Distributed in Australia by Microzed Computers Pty Limited Phone 1300 735 420 Fax 1300 735 421 www.microzed.com.au 86  Silicon Chip Fig.5: screenshot of the UltraScope software. The top window shows a captured square wave, while the bottom window is the “virtual panel”. The side windows are used to control the DSO and store waveforms. much easier than fiddling with knobs to find the trace! Another nice feature is the “50%” trigger button, which automatically sets the trigger level to the “centre” of the waveform. Apart from selectable AC and DC coupling, the unit allows the trigger to be filtered. The LF reject option blocks low frequency triggering lower than 8kHz while the HF reject option attenuates frequencies above 150kHz. Triggering can occur on edge, pulse and there is even a video mode compatible with PAL, NTSC and SECAM video signals (see Fig.3). The DS5602MA can be connected to a Windows PC via a USB cable (not supplied) and is has optional GPIB and RS232 connections via the EM5-COM external module. The scope can be controlled directly from the PC using UltraSco pe (downloadable from www.rigolina.com). A nice feature of the software is the “virtual panel”, a graphical interface that mirrors the oscilloscope, including its LCD screen. Waveforms can be captured locally on the DSO or downloaded to the PC. A 320x240 bitmap file (.bmp) can be exported at the touch of a button. Recording and playing back waveforms is easy. The unit can store up to 1000 frames, spaced at 1s to 1000s intervals. These can be downloaded to your PC for further analysis. Up to 10 settings and 10 waveforms can be stored locally in non-volatile memory and there is a factory reset option. All menus are persistent, meaning that they remember their last setting. The unit can be automatically calibrated and self-diagnostics check that the instrument is functioning correctly. In addition, there are key and screen tests to rule out obvious failures. It has multi-language support, the menu system is simple enough to be intuitive and the use of graphical cues is an added bonus. So what is our overall reaction? The Rigol DS5602MA is a keenly priced, well-featured digital scope which is quite easy to use. It does not have multi-level menus which are hard to access and most of its features are quite intuitive. All of which is great. The big compromise is in the display. While the mono LCD (black or white or white on black, is very clear, its ¼-VGA resolution (only 320 x 240 pixels) is a problem and will mean that fine details of complex waveforms will often be difficult to discern. However, for less than $1000, you do get a lot of oscilloscope. The DS5062MA comes with a threeyear warranty, a user manual and a carry case. Recommend retail price is $799 plus GST. For more information on the DS5062MA and other DSOs in the series, contact the Australian distributor, EMONA Instruments on (02) 9519 3933 or email testinst<at> emona.com.au SC siliconchip.com.au