Abstract: The invention relates particularly to the switching of an SDH low order VC-3 using a high order switching apparatus, such as an STS switch. A low order VC-3 is aligned with a TU-3 pointer to form a TU-3. The TU-3 is mapped into a high order VC-3 type data structure which, in turn, is aligned with an AU-3 pointer to form an AU-3 type data structure. The AU-3 type data structure is suitable for switching by the high order switch. After switching, the AU-3 type data structure is combined with similar AU-3 type data structures and converted into an AU-4 suitable for transmission across an SDH/SONET network. Advantageously, the arrangement is such that each AU-3 pointer has the same fixed value. Hence, conversion to an AU-4 is achieved by a fixed pointer replacement operation.

Abstract: Process and apparatus for measuring variations in a stream of material, such as thickness in a strip from a mill. A radiation source and detector are positioned at a gauging station. The stream of material moves past the station providing an electrical signal varying as a function of material at the station which signal includes a lower frequency component, a higher frequency cyclical component, and a higher frequency noise component. A circuit for providing a thickness output varying as a function of the lower frequency component of the signal, and a circuit providing an output indicating chatter varying as a function of the higher frequency cyclical component. Digital and analog versions are disclosed.