Control electronics in each box energize {HEAD ~ reader coils} to query {TAIL ~ individual RFID tags} 
to query
Control electronics in each box energize { HEAD ~ reader coils } to query { TAIL ~ individual RFID tags }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL