If the FourJaw MachineLink hardware is unplugged it will return 'Offline' in the production timeline. If you do not have access to the production timeline, the 'Machine Connectivity' page will display this machine as offline.
If this is the case please check the MachineLink unit is powered. If in doubt please unplug and plug the mirco-usb power cable back into the unit.
If you're on the Standard and Pro plan you can also setup Live alerts to notify users by email that a unit has gone Offline for a given period.