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