ELAN Home Systems ES370 manuale d’uso

ELAN DIGITAL SYSTEMS LTD. LITTLE PARK FARM ROAD, SEGENSWORTH WEST, FAREHAM, HANTS. PO15 5SJ. TEL: (44) (0)1489 579799 FAX: (44) (0)1489 577516 e-mail: support@pccard.co.uk webs ite : htt p:/ /www.p cca rd. co. uk USBscope50 USER’S GUIDE ES370 Important Notice: Please refer to Safety Data 4.4.1, before using this instrument All Trademarks are duly[...]

CONTENTS 1 OVERVIEW................................................................................................ 5 2 ABOUT THE US BSCOPE5 0 ..................................................................... 6 2.1 General ............................................................................................................ 6 2.2 USBscope[...]

4 HARDWARE SPECIF ICATION ............................................................... 36 4.1 Power Requirements .................................................................................... 36 4.2 Mechanical .................................................................................................... 36 4.3 Environmental .........[...]

Disclaimer This document has been carefully prepa red and checked. No responsibility can be assumed for inaccuracies. El an reserves the right to make changes without prior notice to any products herein to improve functionality, reliability or other design aspects. Elan does not assume any liability for loses arisin g out of the use of any product [...]

1 OVERVIEW The USBscope50 is a digital storage oscilloscope that has the following features: • Single channel scope with BNC input and USB PC interface • Each USBscope50 can be stacked to increase channel count (each requires its own USB connection) 1 • 300V Cat II isolation between BNC ground and USB ground 2 • 50MSample/sec single shot sa[...]

2 ABOUT THE USBscope50 2.1 General The USBscope50 uses a 50MSample/sec 8-bit A-to-D converter. The A-to-D and front-end circuits that process the input waveform, and the digital stages that acquire and store the waveform are all powered from the USB host interface via an isolated supply. This means that there is no galvanic connection between the B[...]

2.2 USBscope50 Architecture The figure below shows a simplified diagram of the USBscope50. A TTE N U A TO R 1Meg CONT ROLLER STAC K CONN AC/ DC BNC AMP COMP PSU DA T A USB CONTROLLER USB Tri g g er ISOLA T ION BAR RIER 8 -BI T AD C Figure 2.2-1 USBscope50 Architecture Diagram Elan Digital Systems Ltd. 7 USBscope50 USER’S GUIDE Iss5[...]

2.3 Using More Than One USBscope50 A unique feature of the USBscope 50 architecture is that up to 4 devices 7 can be stacked to make a multi-channel instrument. In order to use a stacked configuration, you must purchase the stacking connector kit . This kit comprises 3 long lead connectors and 1 short lead connector as shown: 2.3.1 Assembling The S[...]

Repeat this for all except the last scope to be stacked. For the last scope in the stack, do the same as above but use the short length connector. This time, the pins are shorter so they stop well inside the scope’s case. This scope MUST be the bottom scope in the stack . The reason for this is that if you use the long connector, the pins could b[...]

Start with the bottom scope. Hold it in one hand, and put the next scope on top of the 1 st , the same way around. Align the stacking connectors and when the stacking connectors are partly mated engage the front “P” shaped clip (BNC end) on the 2 nd scope into the “P” shaped slot on the 1 st scope. Now, bring the back edge “P” clip (USB[...]

2.3.3 USB Connections For S tacke d Configurations All stacked scopes need a USB connection . A standard hub may be useful for multi-channel stacks to get enough USB ports. Each scope needs about 200mA. Pl ugging more than 2 scopes into a hub will mean that the hub may need to be powered externally. Please refer to the hub’s documentation for mor[...]

Repeat this for each channel in the stack to identify them. If you like, you can stop the softwa re, and unplug all the scopes from their USB connections, and then re-stack them in their channel order. The “about” tab lists all the scopes that have been found. Click on any of the scopes in the list to see more information and an explanation of [...]

2.3.5 S tacking Do’ s And Don’ts • Do power off all scopes (remove USB lead) before connecting and disconnecting scopes from the stack • Don’t remove any scopes from the stack while the software is running • Don’t remove any scopes from the stack while any of them are powered • Don’t stack several scopes and leave one or more scop[...]

2.4 Input Ranges The USBscope50 supports 3 settings on its input attenuator. The ranges at the BNC input depend on the type of scope probe used: A “x1” probe causes no signal atte nuation and will result in nominal full-scale input ranges of +/-0 .3V, +/-3V and +/-30V. The bandwidth of x1 scope probes is generally quite low (10’s of MHz) and [...]

2.5 Probe Compensation Before taking measurements with the USBscope50, the attached x10 scope probe must be compensated to ensure that it is matched to the scope input stage 8 . This ensures that the probe+scope act together to keep the input frequency response as flat as possibl e. Using a scope probe that has not been adjusted to match the USBsco[...]

2. Set the input range to 0.3V/div, x10 probe and coupling to AC 3. Use the channel tab and click on the “cmp” button to turn on the compensation output 4. Set the timebase to 100us/div, and set “auto” triggering, with the trigger level set to about 0%. 5. Now connect your probe tip to the compensation output on the scope. You should see a [...]

output 12 to achieve a clean waveform with minimal mains “hum” 7. Now, slowly adjust the trimmer in the probe body until you achieve the best square wave shape that you can. By this we mean nice square corners and minimum over and under shoot near the edges. A small amount of over shoot is preferable to an adjustment with “curved” square wa[...]

2.6 Acquisition Modes The USBscope50 can acquire waveforms in two different ways. The mode and sample interval (i.e. the time between each data point) is displayed on the main panel 2.6.1 Single Shot In this mode, the ADC is clocke d at up to 50MegaSamples/sec. Each sample is placed into the bu ffer and then the buffer is painted on the screen. Thi[...]

2.6.2 Random Interleaved Sampling This mode is a little more complex and is suited only to observing certain types of waveform. The USBscope50 includes special circuitry that allows it to trigger off the input waveform and also to be able to measure the time between the trigger instant and the first ADC sample that is taken. In this way, several si[...]

RIS mode is not well suited to very slow input signals or signals that have jitter. This will lead to an un certainty in the trigger instant and hence the sweep data will appear in the wrong “bins” and so the displayed waveform will not “lock” on the screen over time. Please note that in RIS mode it is not possible to observe the probe comp[...]

2.7 T rigger Modes The USBscope50 can use three main types of triggering. These modes are used when the “run” button or the “once 14 ” button has been pressed causing the scope to enter the run state. 2.7.1 Auto T r iggering In this mode the acquisition begins just after the software has set up the scope. The scope will effec tively free ru[...]

It is normal for the scope to take several seconds to move from free run to triggered mode when a signa l is first applied to the scope input or is changed significantly. 2.7.2 Normal T r iggering In this mode, the acquisition is primed, but will not start until the input waveform meets some criteria. This mode will cause the waveform on the screen[...]

2.8 T rigger Position The total sample buffer is 3000 point s long. The acquisition can be triggered in Auto and Norm mode from the input waveform. By adjusting the trigger position slider, you can make the trigger position in the buffer earlier or late r in time. This is known as pre and post triggering. Trigger position is adjustable in single-sh[...]

Trigger delay is effective in single-shot mode only. Note that setting a large delay will noticeably slow the overall acquisition rate. Also note that if you forget that you have set up a delayed trigger, it can appear that you can’t find the trigger event on your waveform. Please keep note of whether there is a “<” symbol on the trigger i[...]

2.10 T rigger Threshold You can adjust the trigger voltage that is used for Auto and Norm Modes, either by turning the trigger knob or by clicking on the main plot. After the trigger threshold has been moved, a guide line appears on the screen for a few seconds. 2.11 Full Screen Plot To aid viewing the time plot, a full sc reen mode is available. N[...]

The full screen plot can be placed on top by simply left clicking it. To pop the scope back on top, click the plot with the right mouse key. The full screen plot can be stre tched to any size, and can be maximised by double clicking it. Elan Digital Systems Ltd. 26 USBscope50 USER’S GUIDE Iss5[...]

2.12 FFT Plot (Spectrum Analyser) Each scope channel can be analys ed using a 2048 point Fast Fourier Transform. The plot will be shown in a scalable window and will include all channels selected for analysis, in their respective colours. The lower limit for the dB plot is limited to –54dB. An on-screen cross-hair type cursor allows you to measur[...]

2.13 Math Functions The USBscope50 includes two virtual math channels. These channels are generated using the data from two scope channels called A and B and a mathematical function, like +, - etc. The math functions are accessed under the MATH tab. Note that the voltage range selector knobs may adjust or limit automatically. This is so that the co[...]

2.14 Data Export The channel data and FFT data can be saved using the DATA tab. Simply select the channels you wish to save and click the save button. You will be prompted for a file name. The final files will be stored as: YourSelectedName.chNdata.txt and YourSelectedName.chNfft.txt where N is the channel number. FFT data will only be stored if th[...]

2.14.1 Example Data File There are 3000 sets of numbers, follo wed by a footer that defined the acquisition mode used. -5.0079 -4.7575 -5.0079 -5.0079 -4.7575 -4.7575 … -5.0079 -4.7575 -4.7575 -4.7575 -4.7575 -4.7575 DATA FOR CH: 1 VERTICAL FULL SCALE (+/-v): 30 SAMPLE PERIOD (s): 0.0004 BANDWIDTH LIMIT: False DATE: 21/09/2005 11:32:31 SOFTWARE: [...]

2.14.2 Example FFT File There are 1024 sets of numbers, follo wed by a footer that defined the acquisition mode used. -54.0 -54.0 -54.0 -54.0 -54.0 -54.0 … -54.0 -54.0 -54.0 -54.0 -54.0 -54.0 FFT FOR CH: 1 VERTICAL FULL SCALE (+/-v): 30 FREQ STEP (Hz): 2.44140625 SPECTRAL WINDOW: Rectangular PLOT TYPE: dB(V) Plot DATE: 27/09/2005 18:48:39 SOFTWAR[...]

3 SOFTW ARE INST ALLA TION 3.1 Windows 98SE and Windows M e Before plugging in the hardware: Use the supplied install CD and run the setup program. This will copy all the required files and drivers to your PC. After running the setup program: Insert the USBscope50 into a free USB socket, or into a USB hub port. A USB extension cable can be used if [...]

Once the hardware has installed, there is no need to make any settings for the allocated COM port… the software takes care of all this at run time. Start the USBscope50 software and you will see the following display: To find out what the various bu ttons and knobs do, simply hover over them for a brief explanation. Elan Digital Systems Ltd. 33 U[...]

3.2 Windows 2K and XP 17 Before plugging in the hardware: Use the supplied install CD and run the setup program. This will copy all the required files and drivers to your PC. After running the setup program: Insert the USBscope50 into a free USB socket, or into a USB hub port. A USB extension cable can be used if needed. During installation, two ha[...]

Once the hardware has installed, there is no need to make any settings for the allocated COM port… the software takes care of all this at run time 20 . Start the USBscope50 software and you will see the following display: To find out what the various bu ttons and knobs do, simply hover over them for a brief explanation. 20 You may be prom pted to[...]

4 HARDW ARE SPECIFICA TION All parameters typical @ 20 ° C unless otherwise stated 4.1 Power Requirements Supply Voltage: 5.0V ±10% from host USB bus Total Supply Current: 200mA avg 4.2 Mechanical Mass: 42g typ. Case Material Data: Polycarbonate (UL94V rated) Size (typical in mm): 99.6 21 x 30.6 x 17.5 22 4.3 Environmental Humidity: <80% non c[...]

4.4 Performance 4.4.1 Safety Data and Maximum Ratings Important Safety Precautions Always observe these when using the USBscope50 The USBscope50 contain no user serviceable parts inside. Do not open the plastic housing. There may be lethal voltages insi de the plastic housing. Do not use the instrument if the housing is damaged or is poorly fitting[...]

Isolation rating: 300V CAT II, 500V CAT I between BNC ground and USB ground Transient isolation 24 : BNC ground to USB ground +/-2.5KV Isolation capacitance 25 : 1000pF typ between BNC ground and USB ground Maximum Measured Voltage: Between BNC center and BNC ground: +/-30V. Absolute Maximum Input Voltage 26 : Between BNC center and BNC ground: +/-[...]

Elan Digital Systems Ltd. 39 USBscope50 USER’S GUIDE Iss5 4.4.3 Dynamic Performance Maximum ADC single shot rate: 50MSPS Maximum ef fective sample rate 28 : 1GSPS Sample rates available: 4ns/div to 4s/div in 1,2,4 sequence Sample rate accuracy: 0.02% typ Stacked scope channel skew: ±2ns between any channel pair typ Analogue 3dB bandwidth: 75MHz [...]