Waveform overlay

[Technician]

Please advise if you can... When I open pico 7 and have a waveform on screen, if I wanted to compare it to a previous waveform, how would I get both on the same screen?

Thanks

[ben.martins]

Hello,

Apologies for the late reply. It is of course possible to create, save and import reference waveforms into PS7. If you are looking to create a reference from a previous capture to then compare pre and post fix, the following video will help as I walk through loading a file in and then creating the reference before capturing the live signal. It's quite an old video now as it features PS6 but the PS7 section starts around 5:27.



Steve has also created a video on a similar subject but this time looks at how to load a reference waveform from the waveform library in order to compare before and after. This technique can also be used for 'My waveforms' so if you have uploaded the original file to the library, then you can import the references directly from the library.



The is a small piece on the A-Z section of website on reference waveforms here - https://www.picoauto.com/library/picosc ... -waveforms and also in the training section here - https://www.picoauto.com/library/traini ... d-features.

I hope this helps.

[Technician]

I'm still somewhat confused with the operation of Pico 7 at the moment. When your about 6 minutes in the video you show how to put two waveforms onscreen! The first waveform I can manage, but following the instructions does not make it clear (to me) how selecting A,B,C and D puts the next waveform on screen? In my trials at the moment I can put the first waveform up, but then Pico 7 copies the first waveform and puts that second (same) waveform underneath the first one?

I'm still getting confused how to put two different waveforms on the same screen for comparisons?

[ben.martins]

Hello,

Not a problem. I've put the following video together which I'm hoping will help with any confusion.



Hope this helps.

Kind regards

Ben

[Technician]

Thanks Ben, I've watched the video at work today on Windows 10 and I will need to watch it a few times for the information to sink in. It will probably be tomorrow evening when I try again to compare waveforms as my PC at home is Windows 7 and sort of freezes and becomes unstable with Pico 7 operating as you show in the video.

[Technician]

I had a go last night using two computers, one watching the video and one trying to follow the instructions. I struggled to get two different waveforms on screen. I've tried again today at work. I can't get it to see two different waveforms, i.e. prev and post repairs. Each PC just seems to duplicate the same waveform?

To me the software is over complicated in use. It would be much easy if something like the following was used...

Open Pico, go to open file, select file on screen. select views to provide two views. Select second view, go to open file and select second waveform, click open and second waveform opens in view 2. Now both previous and post views can be seen at the same time.

I try to live by the rule, keep it simple, it will work much easier.

[ben.martins]

Hello,

I'm sorry you are still finding it difficult to create the reference you require. From your last post, you are going to need to save the reference waveform and then import it back into another file. The methods in the videos above look at creating a reference and then taking a live measurement. What you are describing is doing everything post capture. I did touch on it briefly regarding loading saved references but maybe a separate video is required.

I will look to create something for you.

Kind regards

Ben

[Technician]

If it loads up, here is a screen shot of what occurs!

When I try to move the waveforms on screen what you see moves, but nothing is hiding behind them. What you see is what you get, I can't alter it in anyway. Its like the Windows 10 package I'm using is not able to support the software? I've tried this on three computers and all three do the same! I can't seem to get two different waveforms on screen at the same time!

Thank you for your help on this one Ben. I'm sure it is the software packages I'm using rather than user error now, especially after following your video frame for frame.

[Rfmotors1]

I am not sure if I guess correctly based on the picture.
It looks like you are trying to insert reference waveform to your current screen and the reference waveform was recorded with different time/division.
Best practice is to record both waveforms with the same setting, especially the time/div.

Your current screen is 500ms/div so your waveform that you are importing as reference waveform should be recorded also at 500ms/div (5 seconds as there is 10 divisions, half second each or 500ms each) .

For example if your reference waveform was recorded at 10%, just 50ms/div, then it will occupy exactly just 10% (half second) of your current screen which is 5 seconds.
As the time must be the same for both.

Hope it helps.
Roman

[Technician]

Thanks Roman, however, the time/div can be altered to bring both waveforms into line with each other as Ben has pointed out in his video.

It is possible that a person might scope a trace and then check a good trace from the library only to find that the good trace from the library had a different time/div setting from the one recorded from a faulty engine?

In my case to get the scope to record a full 720 degree waveform was difficult at best because I had other issues at the time, i.e. scope connections and loss of trace on screen because for whatever reason,the scope trace did not stay on screen after cranking engine stopped!

I did seem to resolve that issue, but I wanted to compare my bad waveform saved on my pc to a known good waveform saved on my pc, but it seems its not possible to open two waveforms from my hard drive and split them on the same screen?

Thanks