In a voice packet switching network (10), following call path set-up, continuity packets (500a-c) are transmitted between the call originating (100) and destination (101) nodes to check call path continuity. The continuity packets carry time stamps of their (503) and the preceding continuity packet's (504) time of transmission, to permit determination of call path transit delay, and computation of asynchrony between clocks (200) of the two nodes. A call path is considered acceptable if one half ...

The present invention relates to an apparatus for verifying a data path through a digital switch between a transmitting port and a receiving port. The apparatus comprises a transmitter which transmits a test data block in a first predetermined time slot which corresponds to the time slot associated with the transmitting port. A receiver receives the test data block in a second predetermined time slot, which corresponds to the time slot associated with the receiving port. Test logic examines the ...

In a data processing system in which data is sent over a data path between at least first and second devices, a clock distribution network is provided with the capability of selectively delaying the clock signal to either the sending or receiving devices to stress the short and long data paths.

A path control method and apparatus which are well-suited especially for application to articulated machine tools and industrial robots having path-controlled parts, using commands calculated from teach point information and orders calculated from the commands by operations performed without coordinate transformations so that a large number of path points can be evaluated without considerably lengthening an operating period of time.

A dental path of insertion guide which provides visual comparison of tooth surfaces that have been prepared for bridgework. The guide can be straight, U-shaped, or arcuate, and has at least four pins supported for slidable movement thereon, which pins extend vertically upwardly or downwardly and are parallel. A removable cap is provided to facilitate addition or removal of pins from the guide.

A speech path system for a telephone exchange having crosspoint switches of a speech path network comprising semiconductor switching devices of four or more layers, including a memory circuit for storing the operating conditions of said switching devices, a drive circuit of a high A.C. impedance for actuating said switching devices in response to output signals from said memory circuit, a subscriber D.C. loop detection circuit of a high impedance provided at a subscriber terminal of said speech ...

An optical path-length modulator which comprises a tube having at one open end a lens of which the focal length is equal to the distance between this lens and the surface of a concave mirror which is disposed at the closed end of the tube and which has a radius of curvature equal to the focal length of the lens. The tube is carried between and mounted on two spaced apart diaphragms which can flex in order that the tube may move axially. The tube constitutes an armature for an electromagnetic vib...

A method for synchronizing apparatus on the receiving side of a time multiplex or code multiplex transmisson system with apparatus on the transmitting side of the system, in particular in a system which operates in accordance with the SSMA technique, with which system the information is transmitted in a broad frequency band compared with the base band occupied by the information wherein a rapid frequency change modulated oscillation is transmitted by the transmitter at the beginning of transmiss...

Improved aerial weapons comprise an aircraft capable of controlled flight relative to a preselected target, means to automatically control the flight path of said aircraft, means to continuously determine the position of said aircraft relative to said target, means to automatically impose upon said flight path a helical component which at one instant in time passes through a munition release point appropriate for the said target, and automatic means to release the munition at the said munition r...

A circuit board or sheet of homogeneous material having one or more circuit elements adhering to a surface thereof, said sheet providing a low through resistance path between each circuit element and opposed and aligned contacts positioned in surface contact with the opposite side of the sheet while providing a high isolation resistance between out of alignment contacts positioned on the opposite side of the sheet and between contacts positioned on the same side of the sheet positioned an isolat...