We purchased 3 sets of MIRXR1X contact over ip units as a pilot for a customer’s system. In Base Station, for each paired set shown, one of each set shows as Master:True the other is False. The non-Master units will readily accept static IP settings. The Master units will not. I am using these units at remote sites with no DHCP so static configs are required… that is why I purchased these MIRX instead of MIRC units.