There have been users of X-Rite's 391 that received an "Illegal Modem" error while attempting to print. The user would be well advised to ensure that the "Answer to Ring" setting in the network configurations is set to "0". If this is set at anything but "0", the densitometer thinks that it is connected to a modem rather than a printer. Follow these steps to select "0" in network configuration -
1 - Press [p1] 2 - Press [p2] 3 - Press [netw] 4 - Press [cfg] 5 - Press [ring] 6 - Select the down arrow until "0" is displayed. 7 - Press [exit] and then return to the home screen.