Abstract: A method and apparatus for processing information includes receiving electronic information at a second device from a first device, where the received electronic information is sampled periodically, resulting in a plurality of numerical data value samples. The data value samples are analyzed within the receiver to determine slope transitions within the data which are interpreted as high and low transitions representative of bit transitions ordinarily seen in the transmission of digital data. The bit transitions are then converted into a receiving device appropriate usable and readable form, such as bytes (8 bits each) or groups of bytes, as needed. Data bytes may be commands, information, or other indicators useful to the receiving device.

Abstract: An Ethernet-type local area network having multiport repeaters and nodes within a specified distance of the hub is able to communicate high speed digital data over multiple pairs of twisted-pair wires using long symbol group-type ternary coding. Bundle mode termination minimize impedance mismatches. Low-frequency collision detection circuitry permits detection of packet collisions on an a.c.-coupled network. Precise serialized digital to analog conversion is realized using chains of gates to form delay elements with precise delays.

Abstract: An Ethernet-type local area network having multiport repeaters and nodes within a specified distance of the hub is able to communicate high speed digital data over multiple pairs of twisted-pair wires using long symbol group-type ternary coding. Bundle mode termination minimize impedance mismatches. Low-frequency collision detection circuitry permits detection of packet collisions on an a.c.-coupled network. Precise serialized digital to analog conversion is realized using chains of gates to form delay elements with precise delays.

Abstract: An Ethernet-type local area network having multiport repeaters and nodes within a specified distance of the hub is able to communicate high speed digital data over multiple pairs of twisted-pair wires using long symbol group-type ternary coding. Bundle mode termination minimize impedance mismatches. Low-frequency collision detection circuitry permits detection of packet collisions on an a.c.-coupled network. Precise serialized digital to analog conversion is realized using chains of gates to form delay elements with precise delays.

Abstract: An Ethernet-type local area network having multiport repeaters and nodes within a specified distance of the hub is able to communicate high speed digital data over multiple pairs of twisted-pair wires using long symbol group-type ternary coding. Bundle mode termination minimize impedance mismatches. Low-frequency collision detection circuitry permits detection of packet collisions on an a.c.-coupled network. Precise serialized digital to analog conversion is realized using chains of gates to form delay elements with precise delays.

Abstract: A collision detection circuit in a network transceiver detects collision among a type of digitally-encoded signals by detecting for transitions at a timed position relative to previous transitions within a preselected time tolerance band or window. (Manchester encoding is one such binary code, which has all data divided into bit cells containing the complement of a data bit and the value of the data bit separated by a transition ideally placed in the center of the bit cell.) Absent occurrence of such a transition, a signal is generated indicative of the occurrence of a collision between signals. A typical network in which the invention is used is a broadband network or a fiber optic network, and a typical use is in a CSMA/CD (Carrier Sense Multiple Access/Collision Detection) channel as for example defined by IEEE Standard 802.3 (Ethernet).

Abstract: A simple impedance measuring tool is provided for performing an accurate but inexpensive determination of impedance and assurance of an impedance match in an installation environment. The apparatus operates according to a method wherein the average instantaneous voltage on a transmission line is sensed based on the integration of a series of reflections stimulated by a pulse generator. The apparatus comprises a fast repetitive pulse generator, a fast comparator, a flip-flop and a means for integrating the output of the flip-flop to produce an output voltage which can be read by a simple low-cost meter such as a d.c. voltmeter. The output of the comparator is coupled to the data input of the flip-flop, which is driven at its clock input by a variable phase clock output of the pulse generator. The absolute time delay or phase determines the distance at which the measurement is to be taken.

Abstract: Impedance of each termination in a wiring environment, wherein unshielded twisted pair wires with a characteristic impedance at 10 MHz of about 85 to 130 ohms are used as a communication medium for a local area network where run lengths do not exceed about 250 feet between terminations, is matched at each termination by an impedance matching termination and line conditioning apparatus, hereinafter a matching device. The matching device matches impedance of twisted pair wiring to a nominal 50 termination over a bandwidth of d.c. to above about 10 MHz. The matching device comprises a low-pass filter coupled at a first port to a fifty-ohm standard BNC connector and at a second port to a tapped autotransformer means with a d.c. blocking capacitor for impedance matching and balanced to unbalanced conversion, which in turn is coupled to a common mode inductor, which in turn is coupled to terminals for each side of a twisted pair cable.

Abstract: A local computer network transceiver is provided for a distributed control local computer network which applies a signal to a medium which has a DC component wherein isolation is implemented at the medium interface without need for direct current coupling of any active circuit to the communication medium. The medium is typically a coaxial cable. Transmit isolation transformers are coupled across a coaxial coupler, the medium side thereof being coupled in series with a diode. A plurality of transmit isolation transformers may be coupled in parallel to the medium to permit operation at substantially higher frequencies than would otherwise be permitted due to self-resonant frequencies of the isolation transformers. A receive interface through a receive isolation transformer is provided with capacitive balancing to prevent common mode voltages from being converted into recognizable signals.

Abstract: An improved local computer network transceiver comprising transmitter, receiver, collision detection, and power supply circuits. The transceiver is connected between a plurality of host CPU controller interfaces and a coaxial cable with the coaxial cable being utilized as the communication medium at a nominal data rate of 10 megabits per second. The transmitter circuit includes triple redundancy in the output circuits to prevent single and double component failures from causing the transceiver to continuously jam the coaxial cable. The receiver circuit includes input compensation in order to permit use of the transceiver with long lengths of coaxial cable. The transceiver is capable of sending very wide pulses in order to aid in the location of coaxial cable impedance discontinuities (i.e. a time domain reflectometer function), and the ground planes associated with the host CPU interface cable and coaxial cable are physically separated by a plurality of interstage isolation transformers.