Help connecting H3-15.0-SMART to MODBUS

[thommo17]

Hi everyone,

I just got my Waveshare RS485 TO ETH (B) and have it powered with POE and got the settings as per this guide
https://github.com/nathanmarlor/foxess_ ... TH-%28B%29

I'm getting this error when trying to connect the HA plugin

Error connecting to your adapter or inverter. Ensure the adapter is properly configured and is correctly wired to your inverter (see the setup link above), then try again. Details: Modbus Error: [Input/Output] Modbus Error: [Invalid Message] No response received, expected at least 8 bytes (0 received)

I can see in VirCom that when I try and connect it will send and receive packets but I just get that error each time.

I feel like it is how I have the inverter side wired up.

I have an ethernet cable plugged into the meter port and wire 1 and 2 into the corresponding port on the adapter with A to A and B to B. I can see the manual for the inverter says the meter port give out meter 485A and 485B on this port.

Or do I have to use the big COM port plug?

Thanks for any help!

[Dave Foster]

Yes you should be in the big COM port, the meters use a different 485 protocol.

The COM port has pins labelled EMS485 A & B (sometimes just labelled 485A/B) - they are the ones to connect to.

[thommo17]

I can confirm that this worked for me.

I also needed to use the beta version of Nathan's integration in Home Assistant for it to work too