A self-contained RFID-enabling drawer module includes a probe antenna to introduce a robust EM field into a container within a Faraday cage to activate RFID tags within the container, regardless of the container's resonant frequency. A receiving antenna and reader read the data of the activated RFID tags, and a processor and communications module transmit the RFID tag data to a remote processor. The RFID-enabling module is self-contained in that it needs only power and a data connection with which to operate. Where an Ethernet is used, power is obtained by PoE. The RFID-enabling module may be used to retrofit existing medication drawers of a medication cabinet or may be used during the construction of a new cabinet. The RFID-enabling system includes auto tuning of the antenna to dynamically compensate for loading changes on the EM field. Assembly and testing costs are reduced and serviceability of the system is increased.