"rtt interface already open" error when connecting Power Profiling Kit

[gnf]

I am using a setup with a PCA10040 with the PPK as piggy back. I also use a JLink Ultra+ connected to the "Debug in" connector on the PCA10040. I have cut the SB20,21,26,27 on the PCA10040 to break the SWD connection to the interface chip to enable the use of the "Debug in" connector. On the PPK the COM switch is set to DK.

So far, so good. This setup seemed to be working. PPK power plotting has been working, I can download new software to the PCA10040 board with the JLink Ultra+. Disconnecting the cable from the "Debug in" connector enables me to see "true" current consumption.

Yesterday something happened. Now I get this error when trying to connect to the PPK:

2021-12-03T10:03:09.256Z INFO Validating firmware for device with s/n 000682697891
2021-12-03T10:03:09.265Z INFO PPK closed
2021-12-03T10:03:09.267Z DEBUG Found matching firmware definition nrf52
2021-12-03T10:03:12.725Z INFO Opening device with s/n 000682697891
2021-12-03T10:03:12.760Z INFO Initializing the PPK
2021-12-03T10:03:12.760Z INFO SEGGER serial number:  000682697891
2021-12-03T10:03:12.760Z INFO SEGGER version:  J-Link OB-SAM3U128-V2-NordicSemi compiled Feb  2 2021 16:47:20
2021-12-03T10:03:12.761Z ERROR Failed to start PPK
2021-12-03T10:03:12.761Z DEBUG rtt interface already open
2021-12-03T10:03:12.769Z INFO PPK opened

I think it is some kind of combination with which debugger I enable first. If I run the PPK from cold start, it works. But then it seems to have a conflict with the JLink Ultra+. Maybe. Not sure yet. But right now I am stuck. I can't get out of the "rtt interface already open". I tried to close all applications possibly holding a JLink process. I even disconnected the JLink Ultra+ but the error is still there. Any ideas?

Edit:

I accidently found at least three "jlinkarm_nrf_worker.exe" down in the taskbar. Yes, in Task Manager I see them too. Every time I try to connect to the PPK it will open another one of them. Interestingly, when clicking on the "Eject button" ("Disconnect device") one of the processes will close, but closing the PPK window will leave the process behind.

[Stian Røed Hafskjold]

Hi, sorry for the late reply. Did you manage to find a solution meanwhile? It looks to me like a problem with the JLink driver and some stuck processes. Of course restarting the computer would probably help, but maybe the problem just reappears? You can try to download the latest JLink driver to see if that fixes the issue. I will also ask the developers if it's a known problem that the Jlink process persists after the PPK app is closed.

[gnf]

Yes, I think it has to do with the stuck processes. I started using the Eject (Disconnect) button and it has been working since. Maybe I unplugged the USB cable from a running PPK session and that produced stuck processes.