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Pico Scope locks up

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Pico Scope locks up

Postby Guest » Fri Jan 11, 2008 9:39 pm

Product: ADC 212/3 with Pico parallel to USB adaptor

Software: PicoScope R5.18.0 (ADC200 driver v4.83

Computer: Thinkpad T60 (Intel Centrino Duo 1.66 GHz w/ 1 GB RAM)

OS: Windows Vista (Enterprise Edition)

Use of device: Automotive Diagnostics & Education


Problem: The PicoScope software will intermittently lock up and stop responding. When this occurs I can not use task manager to force the software to quit (neither commanding the application or the psw32 process to stop through the task manager will stop the non responsive program).

However, if I unplug the USB cable from the computer the software will respond and I can shut it down. In order to reconnect the computer to the ADC 212/3 I must do the following:

Go into the Windows device manager
Plug the USB back into the PC
Use the device manager to uninstall the USB to parallel adapter
Unplug the USB
Plug the USB back into the PC and allow it to reinstall
Re start the PicoScope software

Sometimes when I do this everything will run fine for a while. However, other times once I start collecting data PicoScope will lock up and I will have to go back through the above procedure again.

Occasionally, prior to locking up PicoScope will reverse the channel data (for example I might be looking at primary ignition amps on ch 1 and primary volts on ch 2, the amperage pattern will switch to ch 2 and the volts will switch to ch 1, then PicoScope will lock up).

In the past I have never had particularly good success with the USB to parallel port adapter and so I mostly used the ADC 212/3 through a parallel port. This no longer is an option though, since I am now using a laptop that does not have a parallel port.

Any help in resolving this issue would be appreciated.

Loren
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Postby makila » Mon Jan 14, 2008 5:21 pm

Just to add a little more to my post above...

The exact same problem occurs when using PicoScope R6.0.12.2

Loren
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USB Adapter

Postby Autonerdz » Mon Jan 14, 2008 6:35 pm

Loren,

You may have a defective USB adapter.

Is this Loren from Morrisville? If so, call me. I can send you another USB adapter to see if that fixes it.

Tom Roberts
(The Picotologist)
http://www.autonerdz.com
skype: autonerdz
THE PicoScope Automotive Authority
In North America
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Postby makila » Mon Jan 14, 2008 6:51 pm

Hello Tom -

Yep... that would be me. I'll give you a call. Thanks!

Loren
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Postby makila » Tue Jan 15, 2008 3:36 pm

Ok... I've been looking into this further and have come up with some further information.

I was able to set the PicoScope back up on an older PC that has both usb and parallel ports.

I also noticed that there seemed to be a pattern as to when the PicoScope software would lock up --> it would very consistently lock up when looking at both ignition primary V & A.

So, I connected the ADC 212/3 using the parallel to usb with the older PC and hooked up to a car to look at primary V & A. Sure enough the PicoScope crashed exactly as I described in the above post. I then connected the ADC 212/3 to the PC through the PC's parallel port and measured the exact same signals with no problem.

Since the problem occurs only with the parallel to usb adapter, I think it is definitely part of the problem (as Tom pointed out in his response). However, I think there is more to it than that and at this point I am not convinced the adapter is defective. I think it may just be confused...

The 212/3 can measure a +/- 20 V range (with 100 V over voltage protection I think). With the 20:1 attenuator on the channel to look at primary voltage this would give a +/- 400 V measuring range. Good for the most part when looking at primary voltage. However, primary voltage sometimes spikes higher than this. Because of the 100 V (or 2,000 V with 20:1 attenuator) over protection the ADC 212/3 can handle this. The PicoScope software displays the "out of range exclamation point" in the corner of the screen and all is good... when going straight into the PC with parallel data. However with the usb to parallel adapter I think the data gets scrambled, PicoScope software doesn't know what to do and locks up.

What I need to know at this point is:

1. If the above explanation seems even remotely plausible

2. If so, is this caused because the parallel to usb is scrambling the data because it is defective or do they all do this because the converter doesn't know what to do with an over voltage issue?

3. Is the solution going to be to replace the parallel to usb adapter or to use a 100:1 attenuator instead of the 20:1?


Thanks,

Loren
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OL

Postby Autonerdz » Tue Jan 15, 2008 4:32 pm

Loren,

Guess we'll find out soon enough if it is your USB converter. I sent you one yesterday.

No, I have never heard of an over limit condition resulting in this problem. Primary sometimes exceeds 400V. Other than going off the scale, this is not an issue with the 20:1 attenuator. In fact, techs sometimes forget the attenuator. :o

By the time the signal reaches the adapter it's just data not high voltage. I can't explain how this might be happening and why the signal type makes a difference. Because you can go direct parallel, the data must be OK up to the adapter eliminating the ADC and parallel cable from the list of suspects. The alternate PC would seem to eliminate a PC issue. What else can it be?

Maybe one of the Pico staff has run into this one before. Let's see what happens with the new adapter (it comes with a new USB cable too).
Tom Roberts
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skype: autonerdz
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Postby makila » Tue Jan 15, 2008 5:32 pm

I don't think that high voltage is making it out of the ADC 212/3, I think that the parallel to usb doesn't understand the voltage out of range signal that is being sent to it encoded as parallel data.

If I understand correctly how it works (and I probably don't :shock: ), the ADC 212/3 is sampling & digitizing the analog voltage input and sending it out as a digital signal in a parallel data format. When it hits the usb converter, the converter translates the parallel digital data into a serial digital signal.

From the looks of what is happening this conversion seems to be ok as long as the voltage stays within the +/- 20 V (or +/- 400 V with the 20:1).

Now, when the voltage goes out of range the ADC 212/3 sends out a digital signal that indicates an out of range voltage... which is correctly translated by the PicoScope software when it is sent directly as a parallel digital signal. However, when the usb converter gets this same signal it appears that it does not translate it properly causing the PicoScope software to lock up.

At this point the question is whether this incorrect translation of digital data is due to a defective converter or that the converter is working properly and just has no way to correctly translate the over voltage data signal that it is receiving.

And it looks like the answer may have to wait until I get the new usb connector to try out... Thanks Tom!

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Postby makila » Wed Jan 16, 2008 10:13 pm

I got the new usb converter and PicoScope is no longer locking up and crashing.

However, when looking at ignition primary volts & amps the data displayed is scrambled and does not reflect reality.

I set the ADC 212/3 to view primary V & A on a vehicle, set up PicoScope 5 to save on trigger, and got the following results (on two different PCs - one running XP the other running Vista)

- with the old usb converter --> locks up & crashes consistently

- with direct connection to parallel port --> No problems

- with new usb converter --> Does not lock up but none of the data saved reflects reality


I annotated and posted screen captures as a Flash slideshow at:

http://people.morrisville.edu/~makila/picoproblems.swf


I also set up a save on trigger session looking a fuel injector (V & A) and had no problems with the old converter, the new converter, or the direct parallel port connection...


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Postby makila » Fri Jan 18, 2008 12:18 am

Tom Roberts of Autonerdz figured out the problem.

RFI was interfering with the usb converter. A grounded tinfoil shield cleared up the signal and stopped the crashing...

Image


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