I have tried to connect the RM J630 to my 24” IMAC with a built in ethernet. I manually changed the IP address to the one you recommended
I have set the Ruida Controll to the same IP address. I have changed cables. Still I cannot connect Lightburn to the Laser. Would the Lightburn Bridge Kit solve the problem. I have also tried connecting with my MacBook Pro. Tried usb and Ethernet connections. I am at wits end to know what to do next. Any ideas or suggestions. Many thanks. 
Generally, without the Lightburn bridge, you have to set the Ruida up with it’s own IP on your local network.
If you’re going from your pc to the Ruida via Ethernet, it won’t plug and play, you have to configure your port to handle it’s own IP domain as the Ruida.
Many systems will use DHCP to hand out addresses. The Ruida is a static only IP, so you have to tell your router about it and for it not to hand out that address when a new device shows up.
You should simplify this with configuring the Ruida to your local lan and talk to it over your pc’s network.
Make sense?
For what I understand the Lightburn bridge works out of the box.
Many thanks. For your input. Pleased to report with the help from the Fantastic support from the LightBurn Team.