UI Functionnalities with multiple JS220


I was tasked here at Paradox to find a good solution for current measurement for our battery operated wireless security modules. It took a lot of research but when I found the gem that the JS220 is as well as the software and support, I was blown away! After some testing with the first unit, we bought 2 more!

Anyhow, I would have some questions with the arrival of the new version of the Joulescope UI (1.0.23).
We want to run the 3 units at the same time (I didn’t know that was an option until I tried plugging all three of them at once, which was a pleasant surprise! :slight_smile: )

1) Is it possible to have three current accumulators at the same time, one for each JS220?

I have tried to add three widgets, and modify the settings of them. The only option to me that made sense to do this was the statistics_stream_source, but by specifying the device’s name didn’t seem to change anything on my side, since all 3 had the same measurement.

2) How do I know which of the signals the annotation is measuring if I have three devices at the same time? It would be nice to toggle on which of the connected device I can annotate, or to have a way to view the different measurements of each scopes.

3) This is more of a general improvement: Would it be possible to enter a precise period for the annotation? For example, if I use dual vertical markers, I would want them to be an exact 15ms time period, without having to struggle by sliding the markers. Also, it would be nice if we were able to slide this block of dual markers without having to move the first, and then the second marker.

To conclude, very satisfied with everything yet! My boss was happy when I found this gem of a device.

Thank you for your time, it is very appreciated!!


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Hi @AnthonyR, and welcome to the Joulescope forum! Great to hear that you have been happy with your Joulescopes so far.

Yes, the Joulescope UI 1.0.x internally supports multiple simultaneous Joulescopes. The actual support between widgets does vary, and we will be working to improve this over the coming months.

1) I tried using the Joulescope UI 1.0.23 with two Joulescope JS220s. I added two Accumulator widgets. I see the same thing you do:


The Accumulator widget does not respect the default and ignores statistics_stream_source. I took a quick look at the Accumulator widget code, and it appears to have some code to handle different sources. However, it obviously is not complete. I created issue #201.

2) The Waveform widget already displays waveforms from each connected Joulescope, but it needs work to support simultaneous devices fully. This is on our list! Here is what we plan on adding:

a. A new legend control widget. This widget will display which Joulescope is which color, allow you to toggle the display on/off for each Joulescope, and select the active Joulescope for statistics.
b. A way to override the dual marker display to select a specified Joulescope.
c. Improved time alignment. Right now, time is generated host-side and be off between Joulescopes by 10s or even 100s of milliseconds. The first step is to implement device-side synchronization in firmware. We will also add hardware synchronization through the GPI/GPO/Trigger signals.

Unfortunately, there is no great way to get the control you want today. Simultaneous Joulescope support is new with Joulescope UI 1.0, and we will get there! You can open multiple Joulescope UI instances and open one Joulescope in each instance. This is how the Joulescope UI 0.10.x and earlier “supported” multiple simultaneous Joulescopes.

3) We could certainly add this feature. I just created issue 202. Please let me know if I misinterpreted your request!

You can slide both dual markers today. Hold the Ctrl key and left-click on one of the markers, like this:

We need to do a better job documenting these types of features!

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Thank you for your answers, it is good to know that those features are on the way ! For now, I will be opening 1 instance for each Joulescope.

As for the Ctrl key and left-click, I don’t know why I didn’t think of trying that! :sweat_smile:

And for issue 202, that is precisely what I meant!

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