Open Server/Manage Devices 

You need to put in either the IP address or the mDNS name for the printer.  Otherwise the device will appear offline.

Memjet will have labeled the printer with a sticker that provides this information. 

Our device's mDNS address was pasted into the window and now it is online.

If you have release 7 or later then you will need to do some further configuration.

Please see here