Abstract: A removable stiffener, which is made of titanium so that it will not be wetted by solder, consists of a thick, straight center member with wedge-shaped feet evenly spaced along its length. A latching pin is included on one end. The stiffener also includes flanges made of thinner stock, running the length of the stiffener on both sides. These flanges strengthen the center member and hold it perpendicular to the card on which the stiffener is installed. The stiffener requires a one-half inch wide channel on the card and a special pattern of slots. To install the stiffener, the feet are inserted part-way into the slots with the latching pin of the stiffener oriented near the latching slot of the card. The card is then bent gently away from the stiffener while the stiffener is being pushed forward so that the latching pin and the latching slot align and engage. When the card springs back the stiffener is latched in place.

Abstract: The Printed Circuit Board Assembly Extraction Tool is designed to provide a method for removing Printed Circuit Board Assemblies from card file assemblies. The Extraction Tool is provided with a rubber bumper that protects the card file designation strip from damage during the extraction process. Also provided is an handle design that accommodates spare rubber bumpers. The handle also provides a way to remove PCBA's from the card file directly above panels by inclusion of a 15.degree. offset in the handle design. The Extraction Tool design allows transfer of the extraction force to the same direction as PCBA removal. Finally, a channel is provided that acts to automatically deactivate card retainer strips while using the tool.

Abstract: An adapter for supporting e number of printed wiring cards onto an electronic equipment rack equipped with means of support for cards of a larger size. The adapter includes end plates mentioned to fit into the mounting hardware of an existing rack normally providing space for larger cards. The end plates and sides being virtually identical to the older type and size of printed wiring card.

Abstract: A circuit for indicating the status of a telephone line at the CPE end, where the status is either on-hook, ringing, or off-hook is disclosed. The telephone line is the normal two-wire telephone line. First, a transconductance amplifier converts a floating voltage difference between the two-wire telephone line into a current. The current is proportional to the voltage difference. Next, a current to voltage converter converts the current from the transconductance amplifier to a single ended ground referenced voltage. The single ended voltage is proportional to the current from the transconductance amplifier, thus the single ended voltage is proportional to the voltage difference across the two-wire telephone line. A voltage controlled switch is turned ON when the single ended voltage is greater than a predefined value indicating the on-hook status. When the single ended voltage is below the predefined value, the voltage switch is turned OFF indicating the off-hook status.

Abstract: A card file adapter assembly for mounting a plurality printed wiring cards of a smaller size than are normally permitted on an associated electronic equipment mounting rack. The adapter is so constructed in size as to be able to be slid directly into existing mounting hardware of an older type providing mounting space for printed wiring cards of a more reduced size.

Abstract: An enhanced subscriber line interface circuit for a digital switching system which includes a line configuration and protection circuit connection tot he subscriber line and to a thick-film hybrid module. The thick-film hybrid module comprises a high voltage interface circuit and a PCM conversion circuit. The high voltage interface circuit provides power to the subscriber line, converts received analog voice signals transmitted from the subscriber instrument into differential voltage voice signals and detects the subscriber lines status. The PCM conversion circuit is connected to the high voltage interface circuit and is disposed to convert received differential voice signals into PCM digital signals.

Abstract: A digital line card for interfacing a remotely located digital telephone to a central office system by a two-wire connection is disclosed. The digital line card consists of a line interface connected to the two-wire connection. The line interface provides a full duplex transmission link with the remotely located digital telephone over the two-wire connection. A buffer is connected between the line interface and the central office system. The buffer converts data between the line interface and the central office system. The line card further comprising a protocol controller connected to the line interface. The protocol controller performs a packet protocol for communications with the remotely located telephone.

Abstract: In order to accomplish the object of the present invention there is provided a movable standoff for maintaining a distance between a backplane and a shroud. Several receptacles are attached to the front side of the backplane and have pins that pass from the front side of the backplane to the rear side of the backplane. Additionally, the pins pass through the shroud. The movable standoff has an orifice extending from a first end to a second end. The pins of the receptacles pass through the orifice. The first end rests against the back side of the backplane, the shroud rests against the second end. Also, the second end of the movable standoff is smaller than the first end.

Abstract: A hybrid balance and combination codec filter circuit used in a subscriber line interface circuit over which a connection is established between a digital switching network and a subscriber instrument. The hybrid balance and combination codec filter circuit in combination includes a transmit section that converts differential voltage audio signals representing voice transmissions transmitted from the subscriber instrument into Pulse Code Modulated (PCM) encoded digital data, for transmission to the digital switching network. A receive section converts PCM encoded digital data representing voice signals switched through the digital switching network into differential voltage audio signals for transmission to the subscriber instrument. An included hybrid balance and echo cancellation section connected between the transmit section and the receive section reshapes the audio band signals output by the receive section.

Abstract: A method of bit rate adaption between a user data rate and an adapter data rate using the ECMA 102 protocol. The user data is received from a user terminal at a user data rate, the rate adapted data is transmitted at an adapted data rate, and the adapted data rate is greater than the user data rate. The user data is either in a asynchronous or a synchronous format and contains a start element and at least one stop element. The method involves the steps of: (1) converting the user data into an intermediate data; (2) storing the intermediate data in a receive buffer; (3) only if the user data is in an asynchronous data format, adding stop elements to the intermediate data; (4) transferring the intermediate data in the receive buffer to an intermediate buffer; (5) constructing a frame using data from the intermediate buffer; (6) storing the frame in a transmit buffer, and; (7) transmitting the frame where the step of transmitting changes the frame into the rate adapted data.

Abstract: A central processing unit arrangement for detecting a fault in a central processing unit system that includes a master processor and a slave processor. Master and slave processors are resynchronized at every bus cycle by conditioning the processors' READY signal with the ADS (address status) signals from each processor (ADS indicates that an access cycle has begun and a valid address is present on the address bus). This method of synchronization was selected over the more traditional method of lock-step, which was deemed impractical to implement given the timing constraints of a high speed bus. Also, the dual processors may not always begin their respective bus cycles on the same clock. In addition, it is necessary to synchronize processors for the first instruction fetch following a reset, because the time of completion of an internal self-test may not be deterministic.

Abstract: A ringing signal control circuit used in a Subscriber Line Interface Circuit (SLIC) for connecting a ringing signal bus to a subscriber loop. The ringing signal bus transmits ringing signals along the subscriber loop to a subscriber instrument. The SLIC includes a High Voltage Line Interface (HVLI) circuit connected to the subscriber loop and the ringing signal bus is connected to a ringing generator that provides a source of ringing signals. The ringing signal control circuit comprises a logic interface circuit connected via an address/data bus to a central controller that is arranged to receive ringing connection signals from the central controller and to generate a ringing activation signal. A ring timing circuit receives the ringing activation signal and generates a first and second output signals. The second output signal is transmitted from the ring timing circuit at a specific time interval subsequent to the first output signal.

Abstract: A method of bit rate de-adaption between an adapted data rate and a user data rate using the ECMA 102 protocol. The user data is transmitted from a data adapter to a user terminal at a first data rate, the adapted data is received by the data adapter at a second data rate, and the second data rate is greater than the first data rate. The adapted data contains a start element and a plurality of data elements while the user data contains a start element and at least one stop element.

Abstract: A message arrangement and method for interfacing a digital telephone Digital system including a Digital Facility Line Card (DFLC) that connects a user operated Telephone Instrument (DTI) to a stored program operated digital Central Office (CO) system. The message arrangement comprises, a DFLC message processor that generates and transmits to the DTI control messages in response to report messages transmitted by the DTI, following a user activated DTI event. The control messages provide the user with visual and aural DTI operating information. The DFLC message processor further generates and transmits to a CO system central controller, device report messages requesting access to, and network services from the CO system, responsive to call processing report messages from the DTI. The CO system central controller sends device control messages to the DFLC which operates in accordance with the received device control messages to generate and transmit to the DTI, DTI control messages.

Abstract: A data adapter for simultaneously providing a low speed channel, a first high speed data channel, and a second high speed channel over a two wire connection; the two wire connection connects the data adapter to a telephone system. The data adapter includes a line transceiver connected to the two-wire connection, the line interface provides a full duplex transmission link with the telephone system over the two-wire connection. A telephone interface converts data between the first high speed channel and a telephone instrument. A rate adapter converts data between the second high speed channel and a data processing equipment. A protocol controller performs a packet protocol on the low speed channel, and routes the first high speed channel to the telephone interface and the second high speed channel to the rate adapter.

Abstract: A tool for extracting a cable connector from a cable shroud. The cable and cable connector are connected to a cable shroud. The extraction tool must disengage the shroud locking tabs before the cable connector can be removed. The alignment members mate with the cable connector and, when fully inserted, disengage the shroud locking tabs. To remove the cable connector, the extraction tool must be firmly attached to the cable connector. This is accomplished by forcing the engagement pins into the engagement holes. The engagement pins are forced into the engagement holes by moving the actuator plate from the open position to the closed position causing the locking apparatus to force the engagement pins into the engagement holes.

Abstract: A digital test card for testing the quality of a digital system in a central office system is disclosed. Where the digital system consists of a digital line card connected to a customer premise equipment by a two-wire connection. The digital test card comprises a line interface which provides a full duplex transmission link. When the digital test card is testing the customer premises equipment the line interface operates as a master; when testing the digital line card the line interface operates as a slave. There is also a relay for connecting the line interface to the customer premise equipment or the digital line card. Connected between the line interface and the central office system is a buffer. A protocol controller connected to the line interface performs a packet protocol. And finally there is a processor. Under the direction of the central office system, the processor controls the operation of the digital line card and determines the quality of the digital system.

Abstract: An electrical substrate including a flexible printed circuit mounted on the substrate arranged to provide electrical contact between the flexible printed circuit and circuit contacts on an associated carrier substrate. Portions of the flexible printed circuit extended from the top surface of the electrical substrate to the bottom of the substrate by way of recesses included in the geometry of the electrical substrate. Portions of the flexible printed circuit are folded under the bottom side of the electrical substrate and fastened thereto by some compliant material. Properly positioned, electrical contact is established between the flexible printed circuit and circuit contacts on the carrier substrate.

Abstract: A method is disclosed for distributing operating program data stored in a common memory area of a digital telephone system, to a plurality of digital telephone system controllers. The method includes transmitting the operating program data from the common memory via a control/data bus to remotely located digital facility test card. The digital facility test card receives and stores a load image of the operating program in random access memory (RAM). A PCM network connection is established from the digital facility test card to each of the plurality of digital telephone controllers through the digital telephone system. The stored load image from the digital facility test card RAM is then transmitted to each of the digital telephone system controllers via the PCM network connection.

Abstract: The process of the present invention allows interconnecting one conductive layer to another in a Multichip Module. The process uses bumps formed by wire bonding, or any other means of forming bumps of 0.002"-0.004" height with comparable diameter. These bumps create an opening through dielectric insulating layers, thereby allowing one conductive layer to be electrically connected to the next conductive layer.