If anyone is interested, I used this Modbus converter, reasonable priced, and it can connect both to LAN or directly to your wifi network (no cables )
You can even have it setup as server and access point so you can also access it directly.
It works fine with my GroWatt SPA10000TL3 BH-UP
Settings:
![image](https://global.discourse-cdn.com/business4/uploads/athom/original/3X/0/4/04a04fae9678c13e9b951bb5693173310163966e.png)
![image](https://global.discourse-cdn.com/business4/uploads/athom/original/3X/7/c/7cf6f555157b1f6f2caef4ba374bb05e234df608.png)
![image](https://global.discourse-cdn.com/business4/uploads/athom/original/3X/b/2/b23c57afabd0fcadcb23f9887e333b5f96e7aa68.png)