I received this question today and just thought I would share it.


Question:

"Hi Tom.  I have the Vantage Pro from Snap-On.  What's the difference the Pro from the Pico?
I really like the Pico ignition scope pattern.  Does the pico do eveything?  How about recording & watching the waveform later on? Any help or suggestion please,?   Thank you Tom."

Answer (applies to Modis as well):

The V-Pro is one of the best choices you could make in a native hand held two channel automotive scope.  The differences between Pico and the V-Pro are many.  Not sure where to start.

The first thing you'll probably notice is the screen detail.  Pico, of course, doesn't have a screen but your PC provides a lot more resolution that the poor V-Pro screen.

As far as sample rate performance, PicoScope will seriously out-perform the V-Pro. 

The V-Pro can record only one full buffer capture.  Pico 6.xx can record up to 127 in a scrolling buffer. 

The V-Pro cannot use trigger on the full capture.  Pico can use trigger. 

Pico software updates are free. 

V-Pro cannot run the scope when you are zoomed out.  Pico can run zoomed out, in, whatever.

V-Pro has a vehicle specific database.  Pico has a technical library but it is not vehicle specific.

V-Pro has PGM functions.  Pico does not......yet.   

V-Pro has big box ignition scope features.  Pico does not....yet.

You can configure custom probes scaling with Pico.  With V-Pro you cannot.

More on recording:

All those V-Pro "screens" that make up the record that is represented by the progress bar at the top is the entire capture.  There are hundreds of screens in that record right?  All that would be a single Pico screen.  The V-Pro only runs zoomed in remember.  You can't see what you are getting with a V-Pro when the scope is running.  All you can see is a small fraction of the capture.  To do that with a Pico, you would have to zoom way in. 

The V-Pro captures the equivalent of one Pico screen.  However, it scrolls.  The old data falls off as the new arrives.  Pico captures many screens each of which can have more data than the entire V-Pro record capability.  Pico screens are snapshots.  These snapshots pile up in a scrolling buffer many times larger than the V-Pro total capacity.  As Pico snapshots, each full capture (screen) is a continuous record but each one is separated by a small gap.  Pico screens are an entire record and, as they scroll into the Pico buffer, there are gaps between them.  The size of these gaps depends on your scope settings.  They are as small as 1% of the data and as large as 50%.

V-Pro users may tell you that there are no gaps between the V-pro screens.  That's true, but Pico has no gaps within their screens.  You have to remember that the V-Pro total capture is only one Pico screen.  For example...Imagine a V-Pro and a Pico side by side with all the same settings on the same signal.  Each is set to a similar total capture time and similar sample rate.  Let's say capture time is one second.  Pico is set to 100ms/div and V-pro something much less so that all its screens add up to close to one second.  V-Pro captures one second of data in a scrolling buffer.  Pico captures up to 127 screen shots of one second each in its scrolling buffer that you can page back through and examine each one in ultimate detail.

V-Pro/Modis work differently than Pico but are very capable scopes.  To get more power than these you have to go to a PicoScope.

Hope this answers your questions.  If not...........


Tom Roberts
http://www.autonerdz.com
PO Box 810
East Olympia, WA 98540
360-455-9130
877-628-4899 Toll Free US/Canada
Skype:  autonerdz
____________________

Autonerdz is THE PicoScope Automotive Authority in North America

Hi Rick,

Things like raster and superimposed views.  I don't have a V-Pro but I think the V-Pro is similar to a Modis.  Here is a little movie showing the Modis on a DIS ignition system coupled to a Pico Mixmaster:

http://www.autonerdz.com/flash/modismix2.html

These are features which may appear in PicoScope 6 as it continues to develop.  Pico does a fine job in lab scope capture of ignition with superior resolution anyway but cannot do the raster and superimposed views at this time.

Utooflyer, I think you may have been drinking... or worse. You have been doing something like that haven't you Utoo?

Hi John,

If that is just the whiskey talking, feel free to delete your own post and I will delete the related responses. 

If you have legitimate concerns, let's air them.

This site is about knowledge, learning and sharing and membership here is still free.  There is a lot more going on in these forums than Pico stuff.  However, the title of this section is PicoScope so obviously most of what is in this area is about Pico 

If you are not sure about me, then talk to me.  I sure have helped you out a lot over the years, especially when you were part of out PicoScope support group.

You don't have to worry about this site.  Thanks to all the great techs here, it's only going to grow and get better.  We will continue to do what we can to facilitate that.

We have all benefited from your past contributions.  Thanks for sharing.  However, if you no longer wish to be part of this community, you are free to delete your membership at any time.  We would miss you though 

Your right, Rick.  The Modis does have an ignition scope type parade where the same number of cyls stays on the screen independent of RPM.  Lab scopes without ignition scope functions don't do this.  You can parade them but the number of events on the screen changes with RPM, so it's not a true ignition scope parade.

Of course, with Pico, you can capture a lot of events and still see the detail when zooming in.  This old movie done on PicoScope 5 demonstrates capturing a snap accel with trigger and examining it.

TFI 4 distributor ignition example with PIP, SPOUT, Secondary, and Primary Current top to bottom:
(have sound on)   

http://www.autonerdz.com/flash/snaps.html

Carl,

I think John referred to a different Carl.  Here are the Wikapedia results for the two names in his last line.  Not sure what this means.  They are both psychiatrists.

http://en.wikipedia.org/wiki/Carl_Jung

http://en.wikipedia.org/wiki/M._Scott_Peck

Both psychiatrists.

Added later:

John has deleted his membership.  Just thought I would add that so you would know it wasn't me that did it.  I have no idea why.  It seems John has some personal issues to work through.  We all get our turn don't we.     Best of luck to you bud.

Thank you Tom.  I'm guessing that with that clip you wanted to show me how to capture a freeze frame snap throttle  using the trigger level.  Have to admit I hadn't thought about it but I'll remember that tip.

Hi Tom

Could you explain that?  "They can't trigger on a capture.  The capture free runs all the time."

maybe im just kidding myself, but today I hooked into the primary on an ignition coil, with an ammeter around the power ckt, and trigger was an rpm adapter on a secondary cable. I was pretty sure I was only looking at 1 cylinder, was I wrong?

Qwix

Hey Quix,

I know, you already get this but maybe I can explain it more clearly.

The Modis/V-Pro trigger only works on a zoomed in screen.  If trigger is not met, the scope continues to acquire data in the buffer and only the screen will stop.  Then if you were to stop the scope and look at the capture, your triggered screen would vanish into oblivion if enough time has elapsed and that screen has scrolled out of the buffer.  You can't trigger the whole capture.

This prevents you from making use of trigger to capture a failure or other event.  There are not enough sample points on one screen to be of much use.

There is more detail on all this in this post we did a while back on an earlier Modis version.  Much of this still applies:

http://www.autonerdz.com/cgi/yabb2/YaBB.pl?num=1135299068/0

Pico has come a long way since then though with the PicoScope 6 developments and the ability to stream into the PC RAM at high speeds.  This allows Pico to pull way ahead of anything else out there right now, as far as raw sample rate power is concerned.

Quix,

I admire your thirst to learn.  You are sure in the right place.  We all have the same affliction.  Jut call us "Autonerdz Anonymous"   

What scope you are using doesn't matter nearly as much as understanding a bit about how it works and where your scope's limits are.  Almost any scope can be used effectively.  Where you get into trouble is working outside your scope's capability without realizing it.  All scopes have limits.  Some just more than others.

If you are interested in The Nerd Series on CD, you don't have to buy it all at once.  Just get Nerd I and I will send you the boxed set.  Then you can just purchase the keys for the other CDs when you are ready.

Glad you have been playing with the PicoScope software in demo.  That gives you a pretty good hands on experience.  What it cannot show is the high speed streaming capabilities.  You need the hardware for that.

You might also find the following post of interest.  This is an example of a modern throttle control system.  The capture shown cannot be duplicated by any other automotive scope today.  This capture is sampled 20x faster than a Modis.  The detail is astounding.

http://www.autonerdz.com/cgi/yabb2/YaBB.pl?num=1180471365

Qwix,

You will not be able to get that much information on the screen with the V-Pro. First of all, you're lacking two channels. And secondly, you don't have the resources. Having to run the scope zoomed in puts you at a disadvantage as well by not being able to see what is taking place. This how you have to run that scope to get any usable resolution. If you increase the timebase, you loose resolution and your sample rate, so you have to run it zoomed in.

I personally don't like running a scope in this manner. An event could happen with out you knowing it. The proponents will just say stop the scope and zoom out and review. Thats fine if you felt something, but what if you didn't? Would you know if an anomoly occured that the PCM recognized and you didn't? No. With those screens flying by at fast timebases, I have no idea. If there is more time on the screen, I would. Even if I got lucky, once I zoom out, the resolution is not on par with what I consider valuable real estate. I can take a paraded pattern with primary ignition coil current and pick out a problem with PicoScope and not do it with the Modis. It is like night and day. Trust me, I've tried.

As far as the Cobalt drive by wire operating at 10,000 Hz, you could grab two channels and see those. In order to see that digital frequency in the timebase shown and the slow analog TPS signal, you would have to operate at 10 mS and only then be able to recontruct that signal with 5 sample points. That is the minimum number needed. That is pushing it as hard as it will go, but it will do it. At 20 mS you are done. It is all about having enough sample points to reconstruct the waveform at longer timebases. The more the better.

I think where many get in to trouble is trying to put too much sweep speed on the screen with the V-Pro or the Modis. The key is to have the timebases small and then zoom out. It's a backwards zoom in a way. It works different. Much of what Tom already posted expains this. The main gripe I have with it is the horrible resolution. This is mainly because of the limited amount of pixels of the screen for display. You can indeed utilize the VGA port for an external monitor.  The hardware is 12 bit vertical resolution from what I understand. Since there is no zoom vertically, this is no advantage at this time, maybe for later. The Snap-on software needs some work in my opinion. The benchmark is already here and has been for some time.

Nerd 1 would be a good CD for you, Qwix. It goes in to great depth on the subject. Also, practice with your V-Pro as much as you can. Scope training classes are all over the place as far as quality. Be careful.  When you're ready for the advanced version, let us know. There is so much to learn. New tricks roll out daily.

Regards,

Carl

Thx for your input I find I get decent information at 1ms sweep, but I record it all and use a pc to view. I was able to pick out a bad crank sensor that way

I havent even played with the zoom out feature much, the small screen doesnt do it any justice

Mwebb Fortunately I have use of the V-Pro , the only one in the shop that does use a scope, so I dont have to buy it But I dont think I can talk the boss into a 4 channel, so the next purchase will have to be mine

Qwix

HI Tom and everybody in general 
My question is what do you think about the vetronix 5100 lab scope?  I have been looking for the specs so I can compared it using the calculator but haven't found them, I am asking you this because thats what we have at this time.