Unexpected multiple problems RS485-USB connection Multiplus II GX

[geromd]

I have multiple problems after connecting the RS485-USB Serial from my Daly BMS with the USB-Hub and my Multiplus II GX with the new driver last evening.
The problem already starts when I connect the USB to the Multiplus. The menu of the serial batterie appeared but then the connection come and go for a few times till it looks stable.
I connected everything yesterday in the evening when the Multiplus was in already in discharge mode and in the morning, when the sun came out, I was wondering that the Multiplus was still in discharge mode, but the real current flow was into the batterie for charging.

I disconnected the RS485 Serial connection for the whole day to read about similar issues in the www. One case had a description, that the USB-Hub need an external power source. So I connected external 5V supply to my DIGITUS USB-Hub, but when I connected the USB to the HUB, the connection was still stuttering.
I disconnected the RS485 again and let the system doing his job. The system was charging the batterie in Bulk mode, but when it was getting cloudy and darker in the later afternoon, the system was in fact discharging current from the batterie but still showed “Bulk charging” on the display.

After all, I disabled the driver in SSH with “sh /data/etc/dbus-serialbattery/disabledriver.sh” and rebooted the system and connected the energy meter without hub directly to the Multiplus. For now the Multiplus is working again correctly without any failings, what mean that it is switching between charge and discharge mode in the correct way.

I tried with the delivered Daly RS485 coverter and also with an original Victron RS485 cable. Both show the same problems. For analysis of the problem I also connected the USB-RS485 cable from the Daly BMS directly to the Multiplus (without HUB) and the driver recognized the device promptly and give a stable connection from the first second (but useless without energy meter). I also used an other USB-HUB from Anker, but the problems of stuttering connection was still the same as with my Digitus Spider USB-HUB.
For now I am a little bit frustrated and don’t know what is the core of this problems and how to solve it. Is it in general a HUB at the Multiplus, that is causing some technical interference of the whole system? Is it the new driver? Is it related to the Daly BMS, so should I purchase a JK-BMS and try again? Or do I need to switch to REC-BMS and try it with the CAN-Connection and give up the RS485 solution.

Had anybody some similar problems or any helpfull advice?

[geromd]

Solved by galvanic isolation of USB-Host port and setting the inverted mode to -1.