question

jpetzrick avatar image
jpetzrick asked

VE.Direct signal drop?

RasPi 4 8 gig with Venus OS 2.92. I have Smart shunt and MPPT 150/70 connected by home made TTL-USB cables. The VE.Direct devices would randomly drop off and the only way to get them back was to reboot the Pi. I decided to try the official $30 Victron cable to see if that helped. There was only one available when I ordered it so I figured it would show if one device stayed connected and the other dropped off. I connected the official cable to the MPPT and to my suprise both devices have stayed connected for 3 days now. Maybe there is some kind of keep alive signal with the official version. Any body have similar results?

Raspberry Pi
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1 Answer
Kevin Windrem avatar image
Kevin Windrem answered ·

The VE.Direct to USB cables are ISOLATED where your home made cables are likely not. That is, the Victron cables have no continuity between the VE.Direct and USB connections. Your home made cables can cause communication issues because they lack the isolation that helps keep the comms stable and avoids other issues like ground loops resulting in current and voltage measurement errors in the device.

The reason the system works is probably that you broke the "ground loop" that existed with your two non-isolated cables by using one isolated cable.

You should use isolated USB cables for all connections.

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