A radio frequency identification (RFID) system first interrogates, in a first mode, one or more particular target zones of the plurality of target zones including a given target zone. Each particular target zone is interrogated with one of the antennas at a time at a first power for the particular target zone. The RFID system monitors, upon first interrogating, for a trigger condition to occur. In response to the trigger condition not occurring, the RFID system continues the first interrogation in the first mode. In response to the trigger condition occurring, the RFID system second interrogates the given target zone in a second mode at a second power with a plurality of the antennas. The second power for the given target zone is greater in an aggregate across the second interrogating antennas than the first power for the given target zone.