DEVICE FOR INTERROGATING AND CORRECTING A SERIAL DATA SIGNAL

摘要

A device is described for the interrogation and correction of a data signal which adopts a finite number of discrete signal values in a consecutive series of data cells. The transitions between the signal values exhibit a nominal minimum spacing. The signal is periodically interrogated with a period which amounts to at the most half of said minimum spacing. If a finite series of successive interrogation values exhibits a permissible pattern, the data value is directly derived therefrom (36). There is a set of further patterns which are not permissible, but which do not deviate excessively from a permissible pattern; the associated data value of the corresponding permissible pattern is then simulated. In the other cases an error signal (34) is formed. The patterm has a length which exceeds the length of a data cell. The inherent redundancy of the data signal is thus partly used for the correction of errors.