In a method or device to sample a web movement, an incremental encoder translates the web movement into two phase-offset output signals. A quadrature decoder generates first and second digital output signals with two respective signal levels. The first output signal is designated as a forward signal and the second output signal is designated as a backward signal. An evaluation circuit outputs a control signal and has a first counter that counts a signal change of the forward signal and subtracts from the count a signal change of the backward signal. A second counter counts a signal change of the control signal. A comparator compares values of the first and the second counters. A disabling device enables the forward signal if values of both the first and second counters are the same so that the forward signal is output, and disables the forward signal if values of the two counters are different.