Error-detecting unit-distance code

A particular kind of unit-distance code is proposed. Unit-distance codes are applied especially to absolute encoders (linear or rotary). The various positions of the encoder are represented by the various code words of the code. In contrast to conventional unit-distance codes, this code offers the possibility of detecting all single-bit errors except the two single-bit errors that cause a code word which represents the adjacent position. Unit-distance codes are characterized by a Hamming distance of 1. Thus, Hamming distance is not a unit of measurement for the code's error-detection ability. Therefore, a Hamming distance is defined especially for unit-distance codes excluding the adjacent code words from the calculation of distances. An application shows the utility of the code in the field of instrumentation and measurement