An elevator control system using vertically elongated single-turn loops of wire movable with the car past a vertical column of stationary coils of wire, one at each floor, which are de-energized one at a time repetitively at high speed. The sudden collapse of magnetic flux from a coil induces a pulse into the loops if the car is adjacent. Each loop has one or more twists so that the polarities of the induced pulses vary in a predictable manner over the vertical length of the loops. When pulses are induced in the loops, the unique combination of positive and negative pulses defines the quantized distance between the car floor and the building floor whose coil caused the pulses. The quantized distance between the car floor and any desired target floor in the building is computed repetitively by adding the pertinent floor heights, as stored in a memory, to the reading obtained from the loops.