Update to PPK2 power profiler desktop app changed behaviour for reverse voltage

[GT Software]

I use the PPK2 to measure the power supplied from a lithium polymer battery to a test device. I use 'Ampere meter' and the 'Enable Power Output' switch in the UI then 'start' to collect power consumption readings.

The test device can be plugged in to USB which supplies power to recharge the battery.

Previously I was able to plug the USB power source in and out while carrying on using the power profiler.

Today the desktop app updated to 3.4.4 and now plugging in the USB or removing it causes the collection to stop. 

Changing 'Enable Power Output' doesn't help. 'stop' then 'start' doesn't help. The log says sampling started and sampling stopped but no samples appear.

Exiting the power profiler and starting it again works fine so it appears to be a desktop application issue.

[GT Software]

At the moment the USB is plugged in, the PPK blue light changes to green. No amount of clicking enable/disable power (seen as DUT ON and DUT off) or changing start/stop or changing the mode will get the blue PPK light back.

Exit the power profiler and start it again, select the PPK device and the light changes to blue again and functional again (with the USB cable in the same position)

[Kenneth]

I will check with the developers if they can comment.

Kenneth

[Kenneth]

We are not able to reproduce the behavior at the moment. Can you provide a verbose log? You can turn on verbose logging in About pane.

Do you see the same problem if you power the DUT with a power bank or a different PC, as it sounds like the issue comes from device management. When the PPK2 switches to green light it indicates that it has been disconnected.

What OS are you running, and what can you tell me about the DUT?

We will continue to look into the issue, but in the mean time a verbose log and some additional details would be very helpful.

Kenneth

[GT Software]

Retesting to get verbose logging I found more details.

I now have two scenarios, one where it all works and another where it stops working until the desktop power profiler is restarted.

laptop and OS being used:

Processor Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz 2.21 GHz
Installed RAM 16.0 GB (15.9 GB usable)
System type 64-bit operating system, x64-based processor
Edition Windows 10 Pro
Version 21H2
Installed on ‎02/‎11/‎2020
OS build 19044.1889
Experience Windows Feature Experience Pack 120.2212.4180.0

The failure mode: laptop USB 3 to switch with the PPK2 and a cable to plug in to DUT. With PPK2 running as Ampere Meter, connecting the cable to the DUT causes the power profiler to stop. As described in the original post.

However, I should state that the USB cable is using a jack to socket rather than a standard USB form factor. The PPK2 running blue light changes to green the instant that the cable (jack) is plugged in to the socket

The working mode: Using two USB 3 sockets on opposite sides of the laptop. With the PPK2 running as Ampere Meter, connecting the cable to the DUT works fine. Lots of unplugging and plugging causes no problems. (This is the exact same jack/socket connector on the DUT)

I repeated the failure mode using the second USB 3 socket, where it behaved as before (i.e. the particular USB socket does not change the behaviour)

Having found the working mode again, I believe that is the successful use case before updating the desktop application power profiler to 3.4.4, so the update is a red herring. My apologies.

I have a working mode so I'm happy gathering power consumption again - it is an excellent tool that has already enabled me to halve the standby power consumption of the DUT

(looking for a way to upload the verbose log file)

Colin