Abstract: The invention relates to a substrate coated with a coating consisting of molybdenum (Mo), sulfur (S), tantalum (Ta) and oxygen (O) atoms present in the form of one or several compound(s) selected from among the compounds of formula (I): MowSxTayOz??(I) wherein w is equal to 0 or 1; x varies from 0 to 2; y varies from 0 to 1 and z varies from 0 to 3; said coating comprising at least 5% at of oxygen and said coating having a dense compact microstructure.

Abstract: A DTE can control the modems attached thereto by transmitting command messages over the data path and analyzing report messages supplied by the modems in return. Each command message is identified by a specific header. A command message intended for a remote modem (34) is intercepted by the local modem (30) and reformatted so as to obtain a supervisory message that is then transmitted at the rate of one bit per baud. A command message intended for a remote multichannel modem (48) is transmitted either by means of a supervisory message or in the data mode of operation. Messages are specifically addressed to individual modems by a special hierarchical address which utilizes information of the network link level on which the desired modem resides together with information as to which terminal (DTE), if any, the desired modem is attached. All locally attached primary modems are assigned an address comprising the link level designation and a first constant.

Abstract: A DTE can control the modems attached thereto by transmitting command messages over the data path and analyzing report messages supplied by the modems in return. Each command message is identified by a specific header. A command message intended for a remote modem (34) is intercepted by the local modem (30) and reformatted so as to obtain a supervisory message that is then transmitted at the rate of one bit per baud. A command message intended for a remote multichannel modem (48) is transmitted either by a supervisory message or in the data mode of operation.

Abstract: A method of and apparatus for determining during an initial training period the initial values of the coefficients of a transversal equalizer in a data transmission system in which the transmission channel creates frequency shift. The received periodic training sequence is modulated by a time-domain window signal whose Fourier transform exhibits a relatively flat central peak and has comparatively low values in the vicinity of those frequencies which are a multiple of the inverse of the period of the transmitted sequence, and the discrete Fourier transform W.sub.k of the modulated signal is computed. The values of the coefficients of the equalizer are obtained by computing the inverse discrete Fourier transform of the ratio F.sub.k =Z.sub.k /W.sub.k, where Z.sub.k is the discrete Fourier transform of the transmitted sequence.

Abstract: This invention relates to a new clock synchronizing arrangement for use in the receiving device of a data transmission system employing PSK modulation.In PSK systems, the received signal x(t), for a given carrier angular frequency .omega..sub.c can be defined by its envelope and its phase r (t) and .phi.(t), respectively. r(t) and .phi.(t) can be expressed by:r(t) =.sqroot.x.sup.2 (t) + x.sup.2 (t) and .phi.(t) = arctan x(t)/x(t)where x(t) is the Hilbert Transform of x(t).At the optimum signalling instant t.sub.opt, r(t.sub.opt) and .phi.(t.sub.opt) normalized (without the data) exhibit the minimum variance. The clock adjustment signal is derived from the variance of the envelope or the variance of the phase of the received signal.