SMA Sunny Boy 4000TL: adding a Waveshare (B) RS485 -> Ethernet card

[digital]

We've had the 4000TL since 2011 and I've finally decided to add an SMA RS485 Interface to enable me to read data into Home Assistant. To connect the interface to the network I've got a Waveshare (B) RS485 to PoE Ethernet converter (Link to Waveshare RS485 -> PoE Ethernet Converter).

The connections I've made are:
SMA link 2 -> Waveshare 485A
SMA link 5 -> Waveshare Ground
SMA link 7 -> Waveshare 485B

When the inverter was turned on for the first time with the interface card installed the SMA panel showed something along the lines of 'RS485 interface upgrade' and I've not seen that since.

After all that, the power LED on the Waveshare shows it's powered up but the Link LED is faint green, the ACT LED isn't lit and I can't get a network connection to the inverter.

Can anyone help please?

 

[wpns]

Nice, thanks for the pointer, I have one on order. Amazing how cheap this stuff has gotten!

Can you get a network interface to the Waveshare? How do you have it configured? It looks like there are a _LOT_ of configuration options, from RS485 baud rate to completely overwriting the UI with an MQTT server. And of course the manual is opaque (one of those "once you know, you know, but until you know, there's nothing comprehensible" paradigms), so I'm glad you are the pioneer. 8*)

 

[Hedges]

Are there terminators at both ends of the bus, and pull up/down somewhere?

Most SMA RS-485 operates at 1200 baud, so try to set that.