New user - Solax X3 Hybrid G4 with DTSU666 connected to inverter via modbus (I think) - best way to integrate this setup with HA - wifi dongle vs RJ45 ethernet?

[darmach]

Hi, as in the topic title - I'm about to become a fresh user of Solax X3 hybrid, connected with DTSU666 counter, and solax batteries.

What is the best / optimal / easiest way to integrate with HA?

Should I use the wifi module, or order the ethernet RJ45 one - which is better to integrate, or this doesn't matter (I'd opt for a wired connection then)

[wills106]

PocketLAN doesn't provide a Modbus Connection.
PocketWiFI 3 does, but they are temperamental at times.
There is a newer PocketWiFi and LAN combined, I don't know if that provides a Modbus connection over LAN / Ethernet.
Recommended solution is a device like the Waveshare. https://homeassistant-solax-modbus.readthedocs.io/en/latest/compatible-adaptors/

[darmach]

I bought Waveshare USB - RS485 adapter on FT232RL chip. Here however I just found that RS485 by wave share to ethernet bridge might be "better"... https://homeassistant-solax-modbus.readthedocs.io/en/latest/modbus-adaptor-setup

Any experiences between those two? Should I return the USB and buy ethernet version?

I assume I should connect the GND to have a common ground between inverter and modbus adapter?

[darmach]

@wills106 do you have any experiences with the above? It's claimed in there that USB adapter can cause problems in HA itself.

Also there is a note on connecting only two RS485 wires, and I'm not sure if I should interpret this as "DO NOT connect GND" - as I'd expect to connect GND too to provide common ground for signal level.

[wills106]

May I ask on why separate DTSU666 is better than using clamps with Solax and his "own" built in metering?

The company installing this claims it does not matter

I'm not an installer or an electrician. I just assumed a Power Meter would give more accurate measurements.
But it might be that they just want to save a few £££?

Also there is a note on connecting only two RS485 wires, and I'm not sure if I should interpret this as "DO NOT connect GND" - as I'd expect to connect GND too to provide common ground for signal level.

Connecting ground on some Inverters actually introduces noise.

USB or ethernet to RS485 shouldn't make much difference. Just depends on what's easier to connect to your HA setup. They also do a POE version of the Ethernet one, so maybe even easier if you have a POE switch.
Ethernet used to be preferred as there was a lot of blocking calls in the old USB code of the Integration but I believe they have all been resolved now.

But I don't use RS485.

[darmach]

Oh, what do you use then? (For now I connected via API exposed on local network by wifi adapter with default integration, not modbus one)

[wills106]

The Gen2 X1 & the Gen3 X1/X3 Hybrids all had built in Ethernet. So can used Modbus over TCP.

They dropped the built in Ethernet on the Gen4 & 5's for whatever reason.