Velleman PCSU1000 PC Oscilloscope

[JRuggiero]

Gentlemen,

Has anyone used the Velleman PCSU1000 'scope? Opinions? Value?

Jim R

[tclark]

It has some nice features (like the FFT) that the scope I just bought doesn't have, but overall I'd prefer the standalone capability of the one I got, check it out for comparison:
www.saelig.com/miva/merchant.mvc?Screen=PROD&Product_Code=PSSA002&Category_Code=PSSA

-Tracy

[MX]

It has some nice features (like the FFT) that the scope I just bought doesn't have, but overall I'd prefer the standalone capability of the one I got, check it out for comparison:
www.saelig.com/miva/merchant.mvc?Screen=PROD&Product_Code=PSSA002&Category_Code=PSSA

-Tracy

Tracy,

Any comments on your scope? I'm needing a nice digital storage scope in the home lab and wonder if this will be a good one.

Thanks,

MX

[tclark]

MX-
I am very favorably impressed with the value of the scope I got. Two channels, digital, color display, RS232 and USB interface to computer, ... ; a very nice set of features for the $$ I paid. It is not quite as refined as the HP and Tek scopes I have used at work, but it is close and is also a factor of 3 or 4 cheaper than their lowest-priced units, and includes a color rather than monochrome display.
Support has been impressive also; the USB-only interface version of the scope came with drivers that would not work with Win98. I wrote an email to the support folks in China to see if I could get an updated driver that liked Win98. They didn't have that, but they exchanged my scope for a version with both RS232 and USB interfaces, for no charge. Now it can link with either my old Win98 laptop (which is usually handier) or to a WinXP desktop.
A colleague of mine recently bought a similarly featured Tek scope. With the computer interface, he paid just over 4x what I did. He is a bit sore about the deal I got, and would gladly have a 'do-over' to buy the Owon scope instead. I can easily recommend this one. Give the folks at Saelig a call (I dealt with Al MacRobbie there) and tell them 'Hi' from me.

-Tracy

-Tracy

[MX]

Thanks for the review! Sounds like it will work fine for my needs. I need to measure various serial and IR protocols and occasional R/C pulse streams and my Beckman 20MHz analog scope just doesn't work for that. I need the storage capability to capture single communication events.

I also use Tek color Gs/s scopes at work. Would be great to have one at home, but not at 10x the cost.

Have an OWON on the way (on sale for $329 right now with free shipping).

Thanks,

MX

[podavis]

I have the 50MHz parallel port Velleman PCS 500 and it's very good, lives up to the published specs. It does stuff like spectrum analysis and scrolling to before periodic trigger signals without any fuss. If the PCSU1000 is the 500 evolved to USB it could be a good value. What's its cost?

[JRuggiero]

The Velleman PCSU100 sells for about US $330. It's available from a number of sources on-line. Ramsey Electronics sells it. I've dealt with Ramsey, and they are okay.

Jim R

[mmormota]

MX-
I am very favorably impressed with the value of the scope I got. -Tracy

Thank you for the report.

I have an very similar Tek scope at work. That one is noisy. It has a noise filter for repetitive signals, but I mostly analyse non repetitive signals. The noise is disturbing.

Could you please upload a screenshot without noise filter?

The price is great, hard to resist. ;)

[tclark]

The Owon scope is notably noisier than the much higher priced HP/Agilent scopes that I use at work, but I don't have the budget for these at home. I don't have a screenshot handy now (I'm at work), but I can bring one in from home if necessary. The screenshots in the manual (downloadable from the Saelig site) show the same sort of noise I see in practice.

-Tracy

[mmormota]

Thank you for the fast reply. Looking into the manual, considering the price, I can live with that noise level. ;)

[JRuggiero]

Gentlemen,

What are your views on 8-bit versus higher bit (10, 12, etc.) PC-based 'scopes? The Velleman 'scopes are 8-bit, IIRC. Presumably, you get better resolution with higher bit-rates (excuse me if I'm not being accurate, I have no education in electronics or digital circuitry), but is it worth the extra cost when examining sine waves or square waves? More complex waveforms?

Jim R

[tclark]

Jim-
A wide variety of scopes are available, because there are an equally wide variety of needs. More resolution, a deeper memory buffer, more bandwidth, etc, can all be good or even necessary features for a given application. But they come at a price. For me at home, the simple end of the scale fit my budget and needs. At work, I have scopes that cost 15x as much, and I sometimes need that extra capability. What you need depends on what you want to do with the scope.

-Tracy

[podavis]

The point that cost is a factor means a whole lot. I suffered for more than 25 years with a terrible Heathkit oscilliscope that cost me the 24 hours it took to build a Heathkit color TV for a friend, the scope was my pay, I don't know what I did to deserve it! The Velleman PCS500 cost about $230 but to me it's worth a lot more than that after the Heathkit.

The attached printouts are Rx channels. The 256 lines of vertical resolution is clearly visible, it works out to 32 steps /division. This is good enough for me. The FFT function does a better job of measuring the purity of sine waves or small signals buried in bigger signals than the eyeball can do and it works great on my Velleman.

[MX]

I got my OWON scope today. Looks like it will work just fine for my needs. I tested by acquiring some I2C communications.

Only problem I'm having is getting the USB interface to the PC to work. It connects ok, but when I go to download the data, it just hangs. Did you get the USB to work, Tracy?

Thanks,

MX

[Mr.RC-CAM]

I have one; the USB works fine on Win-XP SP2. It's too bad the PC based display is static (it requires a manual download every time a acquisition is desired).

[MX]

Hmm. I'm using XP SP2 also. I'll have to try reinstalling the driver.

A static acquisition is fine. I just want to capture things like infrared protocols from camera remotes. I've used a USB scope before (parallax optascope), but I prefer to have the separate physical instrument and just use the USB to capture a waveform.

[Mr.RC-CAM]

Your needs sound as basic as mine then. The only reason I have this scope is to capture waveforms graphics for documentation. Otherwise, I use a Tek scope.

[MX]

I have Tek TDS-684B and TDS-744 scopes in my office at my day job.

The home office has a Beckman 20MHz analog scope, the Optascope and now the OWON. I like the OWON's ability to capture the waveform and then zoom the window for details. The small size is great too, since my "lab" is pretty small.

MX

[Mr.RC-CAM]

Yup, the small size is ideal for me too. However, the limited view angle of the color LCD makes is a pain (I have to dim the overhead lights). It was cheap, so it is hard to complain. However, I will probably purchase a refurbished LCD based Tektronix DSO scope in the near future since I really miss the performance of a professional tool.

[MX]

Yes, the LCD is obviously not a TFT. But good enough for the price. I have a little shelf above my workbench that puts my scope display right at eye level, so it's not a problem. I, too, intend to get a better scope in the future, but this one fits the budget and most of my needs right now.

MX

Edit: You know there's a little knob on the front for adjusting the display contrast, right?

[tclark]

MX-
Yes, mine works with the USB interface on WinXP, no installation glitches. It would not work over USB with an old Win98 laptop I had. My scope also has an RS-232 interface, and that works fine with the Win98 laptop. Normally, I don't have a computer on my workbench and just use the scope as a standalone. Since the Win98 laptop is portable, it makes a visit to the workbench to grab a waveform for documentation as needed.

-Tracy

[MX]

One odd quirk I've noticed on the OWON: I like to set the trigger position at 10%, i.e. about the 1st grid line from the left. Everytime I change the time scale, the trigger position moves away and it takes a while to dial it back to 10% using the big knob. Other scopes I've used keep the trigger at its current position when the time scale is changed. Am I missing some option to prevent this somewhere? I can live with it, but it's annoying.

I'm giving the scope a good test run today. Building a quick little infrared extender for my home AV equipment. All the equipment is down in a cabinet and I can't hit the IR sensors with my remote control from across the room while relaxing in my recliner. I'm putting a sensor up high on the wall so I can hit it from anywhere, and the IR signal is retransmitted from an IR emitter inside my AV cabinet.

MX

[Mr.RC-CAM]

I missing some option to prevent this somewhere? I can live with it, but it's annoying.That is a problem that I immediately ran into. I gave up trying to tame it. It really is annoying and I would be interested if someone has found a solution to it. Most of my measurements are expanded views, so this issue is not pleasant at all and makes the task a bit tedious.

[mmormota]

Gentlemen,

Has anyone used the Velleman PCSU1000 'scope? Opinions? Value?

Jim R

I just received my scope from apogeekits. (they answered my emails immediately, and ship to Europe on an affordable price)

It's working as advertised. The software is a little bit simple, just very basic functions. However, it's ok for average hobby work.

pro:
- considering it's 8 bit only, the resolution and noise is good, definitely much less noise then my Tek TDS210, clean output without averaging
- stable synch
- keeps the trigger position on timebase changes ;)
- spectrum analyzer (well, similar function...)
- transient recorder
- single usb connection, no need for external power supply
- good 1:1 & 1:10 probes
- the oversampling trick seems to work, good for high freq measurement

con:
- the display is not real-time, first a/d a scan then display it, really disturbing at low timebase settings
- no advanced synch functions, like hold-off, pulse shorter/longer then..., video
- no double time base
- record memory could be longer, it's only 2 times the display window
- inaccurate DC voltage readings on the numerical window, the zero value depends on the voltage range settings, the highest error I observed is 0,6V at 10V/div, much less in other ranges, strange
- only 3 digits in freq measurement

My general opinion:
Good simple oscilloscope for general hobby work, especially for the price. (the labor scopes at work have the functions I missed but that scopes are way more expensive)
Could be a great little device with some advanced sw functions.

Final:
I am happy with it. :D

[podavis]

mmormota, glad you like the PSCU1000. I just used my PSC500 last weekend to get a PIC12F683 based servo tester debugged, it was great running the oscilloscope in a window next to the PICKIT2 application with MPLAB running. The only nit I had to pick was that it would have been nice to have finer scroll control over the vertical and horizontal positions.

[mmormota]

mmormota, glad you like the PSCU1000. I just used my PSC500 last weekend to get a PIC12F683 based servo tester debugged, it was great running the oscilloscope in a window next to the PICKIT2 application with MPLAB running. The only nit I had to pick was that it would have been nice to have finer scroll control over the vertical and horizontal positions.

I did the same with icd2 and a dspic30f4013... :D
To have finer scroll control, I select the control with the mouse, then scroll it using the keyboard arrows.

[podavis]

I did the same with icd2 and a dspic30f4013... :D
To have finer scroll control, I select the control with the mouse, then scroll it using the keyboard arrows.

You must be an old hand at PIC to have used a 16-bit MCU for the job. I was able to get ~1000 steps with the 12Fxxx by running it at 4MHz and using the 16 bit preset timer in a btfss loop, did the job with a small amount of code. I think it would have to run at 8MHz to get 1 us resolution because the btfss loop takes 2 us at 4MHz.

I think I tried that but it still jumps in discreet steps and I couldn't get the bottom trace of a square wave to sit right on the grid, no biggy. I'll try it again.

edit: Tried the arrow key, this put the trace on the grid, good tip, thanks.

[mmormota]

The job is different, just the oscilloscopecope and the PIC development is similar... :D

You can get 1 usec resolution at 4 MHz using the
addwf PCL, f
nop
nop
nop
nop

code for creating the 1 usec resolution part, and a 4 cycle loop for the rest.

[thirsty]

Have you guys checked out the bitscope? www.bitscope.com - they do a couple of instruments for not much more than the Velleman offering but with many more features and the software is also pretty comprehensive.

I've just spent a couple of weeks researching these tools and the only thing I found that comes close feature wise was the elab-080 from www.dynoninstruments.com.

I reckon the additional logic inputs will be very useful.

Regards

Tony

[podavis]

...You can get 1 usec resolution at 4 MHz using the
addwf PCL, f
nop
nop
nop
nop

I should have been clearer, I'm using the the internal oscillator set to 4Mhz, 1MIPS. Paul

[JRuggiero]

Gentlemen,

Thanks for this info. I note that the ELAB-080 from Dyno Instruments has no spectrum analyzer function. Does anyone miss this? It seems to me, as a naive user, that without a spec.an. function, it's not possible to look at harmonics of a sinusoidal wave form, which I'd like to do.

On the other hand, one day I'll want to look at logic signal wave forms, which the PSCU1000 doesn't seem to have. What's a young boy to do?

Jim R

[thirsty]

Check my post re: the bitscope - it has both of these features (the 310 model),

Regards - Tony

[JRuggiero]

thirsty,

You are only too right re Bitscope 310. I checked their Web site.

Jim R

[thirsty]

Hey Jim.

The software provided by Bitscope is release standard also whereas the software provided by Dynon is beta software hence probably isn't as usable.

I bought the pocket scope (BS50) recently after going through this whole process. There's lots of functionality there plus they include the schematics of the design of the scope in case you want to see how it all works,

Good luck choosing :)

Regards - Tony

[s3r4ph]

Am I correct in reading that the Vellemen USB scope does NOT display signals to your computer screen in real-time? This would seem like a VERY bad thing, for troubleshooting and digital analysis.

Please clarify this:
I have one; the USB works fine on Win-XP SP2. It's too bad the PC based display is static (it requires a manual download every time a acquisition is desired).

[mmormota]

Am I correct in reading that the Vellemen USB scope does NOT display signals to your computer screen in real-time? This would seem like a VERY bad thing, for troubleshooting and digital analysis.

Please clarify this:

It's not true. I have a PCSU 1000, and there are the usual synch modes, only the single shot is static... ;)
Of course there is an inherent delay, if the trigger point is in the middle of the displayed time slot.
Pretty good scope for the price.

[s3r4ph]

Thanks alot,

I've been messing around with the demo today, and I was just waiting on a reply about the real-time display. I'll probably end up buying it. 60MHz for that price is probably the best MHz for the dollar that I'll find.

[mmormota]

I ordered it about a year ago, and happy with the features. I use it for hobby projects, uC based devices for RC etc.

I am EE, have practice with high end scopes as well.
Of course there is no comparison in high speed or complex measurements, but for the usual home projects it's just good enough. For the time, I didn't had to bring home a better scope for weekend, as the small Velleman did the job.

The most disturbing missing feature so far: no hold-off function. Disturbing, because I often watching ppm signal, without hold-off the pulse frame is moving...

[s3r4ph]

I can see how that would be a problem. I don't think I'll really need as high as 50MHz, but I plan on doing some RF work as well as some PWM motor control. I'm probably OK with a 20MHz O-scope, I'm still shopping around, a stand-alone box looks nice, and the Owon at the start of the topic is nearly the same price. But then again... the frequency analyzer is a nice touch...

[MrBungle]

The job is different, just the oscilloscopecope and the PIC development is similar... :D

You can get 1 usec resolution at 4 MHz using the
addwf PCL, f
nop
nop
nop
nop

code for creating the 1 usec resolution part, and a 4 cycle loop for the rest.

Or:

addwf PCL, f
goto label1
label1 goto label2
label2 ......

:D

[GeorgeP]

I have been reading up on both the Velleman PCSU1000 and the Bitscope BS50U (as they are both comparable in list price). Unfortunately I have come to the conclusion that I like the Bitscope hardware and the Vellman software :-( What a deal.

This winters project is a PIC based battery charger. The PCSU1000 (PC-Lab2000SE) has the Transient Recorder with a scan rate down as low as 2000 seconds/div. This would be over 11 hours, well within the 4 hour scan rate I would like to use to watch the discharge/charge. It appears that using the Bitscope DSO software, the slowest scan rate I can use in the Oscilloscope mode is 500ms with the multiplier set to 500ms would give me a 1 second/div rate. I did email the folks "Down Under" and they responded that I can do this using their DDR capture. From what I can see on the Demo, I would have to capture to the DDR while in the 500ms scope mode and then -after- I'm done with the 4 hours, replay the DDR and see the charge graph in a condensed mode. Anyone with a Bitscope care to comment on this? I did reply back and ask them to give me a step-by-step instruction on how to basically do what the PSCU1000 is doing with the Transient Recorder but I have not heard back yet.

This is not the only use I have for a PC based scope, but for right now it is the current one. I feel that over the years I would make more use of the Bitscope, but I really do want to have something with a slow scan rate for other projects as well.

tnx
George

[AndyKunz]

George,

What are you really looking to see in the data? The slow charge of cells? Or to capture transients? Why not just use an ADC on a PIC (a second one, perhaps?) that provides the data at whatever rate you want to capture it into your PC. You can easily have the PIC generate a CSV file which makes for a nice graph source. No, it's not real time - but that's why you hook it up via serial or USB port to your PC and write a VB program to refresh the display after each sample it receives.

The full data is not on their website yet, but Microchip has a PIC24 with QVGA display module coming out "soon." You can see the demo video if you go to www.microchip.com and then search for QVGA. This pulls up a link to the .FLV file of the demo, which you can then convert to MPEG or whatever floats your boat using RivaEncoder (www.rivavx.com for free download). This platform would be an ideal tool for building your own sorta-o'scope. Ask your local Microchip salesperson or FAE for more information.

Andy

[GeorgeP]

George,

What are you really looking to see in the data?

Andy


Andy...

Good Question. I also have a Eagle Tree Data Logger, but it is mounted on my Corona Heli. I could use it as a data logger to watch the battery voltage during the Charge cycles of the charger I want to build, but I'm looking for a excuse to spend some money on a scope. The charger is just one of the many projects I have plans on playing with and the others require the faster scan rates and Spectrum analyzer abilities of the two PC Oscilloscopes I sighted above.

Having a foot in both the PIC and Ham Radio hobby I have a need for something that will satisfy both Digital and RF.

Opps, I guess I didn't really answer your question.... Voltage/Current & Delta V peak.

tnx
George

[GeorgeP]

Well I did get a answer from Bruce at Bitscope Design. He at first said that I could use the DDR software to get the 4 hour scan rate like a transient recorder but when I asked him to give me a step-by-step instruction on how to set this up I got the reply:

>
> The current DSO software can record the data you want but it will not
> replay it as a continuous chart of 4 hours duration at present. This
> capability is coming soon to the DSO for use our new BS100U and soon
> to be released BS320N which both support up to 1 hour per division.
>

I don't need a record/playback function, just a slower scan rate, but from what he described it appears that the scopes input is first captured/regenerated then displayed to look like real time. So it looks like for now at least, Bitscope is off my list. Too bad because I like all the other features it has, but I really want/need a transient record function to watch the charge curve on a battery pack.

George

[mmormota]

Choosing the Velleman you get not only a working transient recorder, but a toolkit. Using the toolkit, you can write your own recorder application for your specific requirements.
A .dll includes the hw specific functions, and there are source code samles how to use them. Very good starting point for developing an automatic battery tester station.

[GeorgeP]

Yes, I will probably end up with the Velleman PCSU1000 because not having the ability to display a very slow scan rate (Transient Recorder) is in my case a deal breaker.

I have been looking at the BS50U which is about the same price and am surprised that for all the additional features it has (8 Logic Inputs, Wave Form Generator, deeper memory, and so on) it lacks something so basic. Bitscope also includes the .dll so you can write your own software, but for that price I'd rather not.

Anyone get a good look at those Hantek DSO-2150 scopes that are flooding Ebay? Sure a bunch of them for sale, but a Google search turns up very little about them (or at least in a language that I can read :confused: ).

George

[AndyKunz]

Why do you need a transient recorder on a rechargeable battery? They make great filters.

How transient is transient?

Andy

[mmormota]

Why do you need a transient recorder on a rechargeable battery? They make great filters.

How transient is transient?

Andy

A "transient recorder" is a long term data logger, not a special device hunting for short spikes or similar... ;)

[AndyKunz]

Totally different use of "transient" from anything I've ever done. I look for "transient response" and "transient persistence" and other transient (ie, short term) things. The HP data loggers we use run days or weeks - but we've never called them a "transient recorder."

Thanks for the clarification.

Andy

[GeorgeP]

Transient Recorder = Chart Recorder = Line Recorder = Roll Recorder = Data Logger. Different names but pretty much the same result. Plot a input over a long period of time. (long meaning seconds/division vs ms or us per division.

George

[phil_g]

Has anyone tried the Swordfish?
http://www.easysync.co.uk/index.html?lang=en-uk&target=d16.html
I quite fancy one of those... the only thing that puts me off is the 5mhz analogue bandwidth... not sure why that should be so low on a 40mss adc... I've queried it with them, maybe its a typo.

Phil

[mmormota]

Even more painful, that it's single channel only.