Abstract:
The present invention relates to a method of coding a data flow carrying binary information in a local transmission equipment. The data flow comprises two kinds of data signal elements and control signal elements, whereby an optional polarity on the line terminal of the transmission can be selected. The coding method uses four different binary code words 0101, 1010, 0011 and 1100, so that the first kind of the data elements corresponds to one of the code words 0101 or 1010 and the other kind of the code words corresponds to one of the code words 0011 and 1100. One or the other of the code words is selected so that more than two of the code words will not follow one another upon the coding of more than two data elements of the same kind.