UC400Eth not visible over Wifi

[onetimeasker]

My friend and i are trying to install a Stepcraft machine, and we have successfully done so with a direct connection. But the whole reason for going with the Network-enabled controller was to hook it up to a wifi-enabled router/modem, and be able to control and run the CNC while being able to move the computer around and use it in some lower capacity at the same time (do some word, email checking etc, without being in the room with the noisy CNC machine).

Now when the controller is connected trough direct ethernet cable, all is dandy.
When we plug that same controller into the wifi router, the controller is no longer visible on any network, and is not able to be pinged on it's original IP-address.

We both have quite some knowledge of computers, but none at all about networking. Can somebody help us out here?