The Autonerdz Community Forums - Stumbling out of the gate

Tom Merritt

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Stumbling out of the gate
Apr 13^th, 2008 at 10:01am

This is my first exerience with an oscilloscope. I have the 3223 unit.

I am trying to capture and analyze some waveforms from a 1979 Mercedes 450 SEL 6.9 to trouble shoot an idle issue.

I am using the MI074 probe along with the 600A probe and the 20:1 attentuator. After figuring out that I needed to turn off the triggers to get the capture to work I got the attached waveforms. The first is from the king lead. The next 4 are from cylinders 5,6,7, and 8. The last is a relative compression test attempt. Note that I used the 20:1 adaptor for all but the relative compression test.

I also used the 6.0.13.3 software recommendations for the settings for each capture.

Here is my question. When I look at the pdf help pages that Picoscope provides the ruler scales don't match those inside the software when I open each of these waveforms. I can't figure out how to change the scales (voltage and time) to match those of the pdf help page examples.

I know I'm making some bone headed mistakes but if Tom or someone on the board could point them out and get me unstuck I would appreciate it. I know I've got a lot to learn and just want to get grounded on some of the fundamentals and build from that.

Thanks,

Tom

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rel_comp.psdata (8 KB | )

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Tom Merritt Freshman Member Offline Posts: 7	Re: Stumbling out of the gate Reply #1 - Apr 13^th, 2008 at 10:02am Also, please advise how to attach multiple data files per post.
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Tom Merritt Freshman Member Offline Posts: 7	Re: Stumbling out of the gate Reply #2 - Apr 13^th, 2008 at 10:03am I'll just leave these three files until I get the multiple attachment thing figured out......
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Tom Roberts

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Re: Stumbling out of the gate
Reply #3 - Apr 13^th, 2008 at 10:37am

Tom,

You can only attach one file per post.

You do not have an signal in either of those files, just a lot of zoom applied. You do not need the attenuator with the secondary probe or the current probes. You only need them when you expect an input to the scope of over 50 volts. The secondary probe is already 10,000:1. (1KV=100mv)

We provide PicoScope specific help in our Picogroup areas. You might benefit by subscribing tho our PicoScope support and training package.

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Tom Merritt

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Re: Stumbling out of the gate
Reply #4 - Apr 13^th, 2008 at 12:00pm

Tom,

Thanks for the info!! I tried to email you yesterday about the cost of support but they both got caught by your spam filters.

No question that I would benefit from the support.

I thought since you said I would need the 20:1 adaptor that I needed to use it for the probes I ordered from you. Better to redo than to damage something.

Thanks!!!

Tom

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Carl Grotti LSD Guide Picogroup Offline Deceased Posts: 1,501	Re: Stumbling out of the gate Reply #5 - Apr 13^th, 2008 at 12:39pm Tom, The only time you need attenuation is when the ADC inputs exceed 50 volts for the 3223. Primary igniton can easily shoot up over 500 volts. Injection spikes can go around 100 volts. These are two instances that require an attenuator to protect the scope.
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Tom Roberts

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Re: Stumbling out of the gate
Reply #6 - Apr 13^th, 2008 at 1:53pm

Quote:

I tried to email you yesterday about the cost of support but they both got caught by your spam filters.

Tom,

I don't have any spam filters except locally on my own machine and I received nothing from you in my spam trap.

Are you sure you used the correct email? If you got any returned mail messages I would like to see them. If there is any filtering going on at my ISP I will need to forward these to my attorney.

You can email me direct from my forum profile or use the contact form on the web site.

Here is a link to the support subscription option:

http://www.autonerdz.com/picokit.htm#_DOH!__I

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« Last Edit: Apr 13^th, 2008 at 2:15pm by Tom Roberts »

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Tom Merritt

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Re: Stumbling out of the gate
Reply #7 - Apr 13^th, 2008 at 2:38pm

Tom,

Here is the question I was trying to send you off the board if you feel inclined to take a look......

I am still not able to capture any useful info and can't figure out what I'm doing wrong.

I'm using the inductive problem clamped on the king lead and the ground attached to a common engine electrical ground. I using the default settings from the Picoscope software except that I'm setting the Trigger to none (king lead.psdata default and secondary pickup). I click Go and I see waveforms streaming across the laptop display. I click stop after a couple of minutes and then do a save as to the Waveform folder. When I open the waveform back up I have nothing just like the ones I sent you. Noise only.

I think I am unclear on a basic concept. I had thought this scope captured a data stream which would be only limited by hard drive space? Not that you would want to capture that much but it appears when I save I'm only saving a single small time interval out of the buffer. When I do a save as and look at the properties of the psdata file it is only a very tiny file between 10-15 KB.

I may go back out and try the second probe you sent me and CHB to see if that has anything to do with it.

Very sorry to seem so dense with this. I thought I would at least be capturing some valid data at this point and be able to start to learn how to interpret it.

Thanks,

Tom

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« Last Edit: Apr 13^th, 2008 at 4:29pm by Tom Roberts »

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Tom Roberts

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Re: Stumbling out of the gate
Reply #8 - Apr 13^th, 2008 at 4:36pm

Tom,

Thanks for the email info. Sorry, I removed that from the board because I didn't want my email address harvested. Not that it has not been already Tongue

The present automotive presets do not make good use of your 3223 scope. You are better off setting it up manually. You need trigger to stabilize the waveform on the screen.

You will need to dial up the sample rate and increase the time base for one thing.

Our extensive tutorial movies that come with the support package cover most of the operational issues.

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Tom Roberts
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Tom Merritt

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Re: Stumbling out of the gate
Reply #9 - Apr 13^th, 2008 at 5:29pm

Tom,

That explains a lot!!! I thought that one of the big selling points of the automotive picoscopes was that there were correct menu driven settings and examples for many of the basic captures?? If I had known that they weren't usable I'm not sure I would have bought a picoscope.

On the fee for the support I would not hesitate if I were a pro and using this for a work situation but mine is for personal use only and I only have 3 vehicles at present. I did this to myself but what is frustrating me right now is that I've got about $ 1300 in the scope and probes I got from you which is only about $ 300 short of what I could have spent to get a package with support.

I'm probably going to have to figure this out myself given the circumstances.

Sorry about the email address.

Thanks,

Tom

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Tom Roberts

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Re: Stumbling out of the gate
Reply #10 - Apr 13^th, 2008 at 5:43pm

Tom,

The automotive presets were made mostly with the old 212 series. They were not optimized for best performance on those. Now with these 3000 series scopes they only utilize a small percentage of the scope ability.

They are still a great resource for waveform examples and technical description with photos of hook ups etc. Pico is working on updating the library and when this is available it will be in a free software upgrade.

But, it's still best to learn how to set it up yourself and get the best performance and results then save the files as your own custom setups.

You should still be able to get a pattern with the presets if you have attached everything correctly. (no attenuators for secondary, etc.)

Call me......I think we can help each other. I called Earthlink about the mail blocking. Doesn't look good.

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Tom Roberts
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Tom Merritt

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Re: Stumbling out of the gate
Reply #11 - Apr 13^th, 2008 at 6:12pm

Tom,

Thanks very much. I'll give you a call tomorrow afternoon. I downloaded all the manuals off the Picoscope website and they all seem to be outdated although I think v6 just came out.

It might be a better use of your time if I set this up on the car and then call you. I'm feeling guilty about wasting your time. It is a classic case of thinking the auto stuff in the software works so it will be easy to run out and grab some waveforms and begin to study them.

Thanks!!

Tom

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twelch Freshman Member Picogroup Offline I love YaBB 1G - SP1! Posts: 36	Re: Stumbling out of the gate Reply #12 - Apr 13^th, 2008 at 6:24pm Tom Merrit, Tom Robert's Autonerdz disc set is worth every penny. The support is great too, but if you want a good understanding of how scopes work and how to use them get the discs! I have been using scopes for almost 15 years and Tom's discs cleared up a lot for me. I think I have watched them 4 times start to finish.
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