Abstract: In a radio paging method of transmitting message information from a subscriber's substation (32) through a base station (30) to pager receivers (31) in the form of a radio calling signal, the message information is divided into a plurality of species to which key codes are assigned, respectively. When a selected one of the key codes is indicated from the substation prior to transmission of the message information, the base station sends a request to the substation in compliance with the selected key code to receive, as the message information, a message indicated by the request. The indicated message preceded by the selected key code is carried from the base station to the pager receivers by the radio calling signal. Each pager receiver reproduces the indicated message with reference to the selected key code. The substation comprises a push-button telephone set to send each message to the base station.

Abstract: A device for remotely controlling the position and orientation of a camera borne by a vehicle includes a first support member including two arms and an intermediary bracket. The arms have first ends pivotally mounted in a substantially vertical plane to the vehicle for movement in the vertical plane and about the substantially vertical plane, and opposite, second ends pivotally secured to the intermediary bracket to form a pivoting parallelogram structure, with the intermediary bracket always remaining in a substantially upright position during the movement of the arms. A parallelogram jack is pivotally secured between a substantially fixed point of the parallelogram structure an one of the arms for pivoting the arms in the substantially vertical plane. A rotation jack is pivotally secured between a fixed point of the vehicle and at least one of the arms for rotating the arms about the substantially vertical plane.

Abstract: In a pager receiver responsive to a call number signal preassigned thereto, a decoder (25) detects the call number signal to deliver a call indication signal to a loudspeaker (27) and is connected to a connector (36) for use in releasably receiving a controller (35) for detecting a message signal which follows the call number signal. A circuit portion (27, 150) is connected to the detector and the connector to produce the call indication signal simultaneously with detection of the call number signal when the decoder is singly operated. The circuit portion produces the call indication signal after detection of the message signal when the controller is coupled to the decoder through the connector.

Abstract: In a time-division multiplex transmission system, a host machine (3) and a plurality of addressable terminals (51 to 56) are connected together by way of a signal line (6). The same address (A) is assigned to a group of the terminals (51 to 54) so that the group of terminals (51 to 54) may be placed under control at the same time upon receipt of a transmission signal (SS) from the host machine (3). Reply signals (RS1 to RS4) from the respective terminals (51 to 54) are adjusted so that they are sent back at different points in time. This enables the host machine (3) to determine which of the terminals sent back the reply signal (RS1 to RS4).

Abstract: Remote control apparatus for controlling a number of pieces of equipment in which each unit includes a microprocessor which produces a first remote control signal on its data bus line and an interface circuit including a first latch circuit which receives the first remote control signal from the data bus line of the microprocessor and a second latch circuit which receives a second remote control signal on its input terminal and transfers the second remote control signal to the data bus line of the microprocessor. A common input/output terminal receives the first and second remote control signals and a switching means is connected between the common input/output terminal and a reference point such as ground and the switching means is controlled by the first remote control signal to pass it to the common input/output terminal.

Abstract: In a contention type of communication network, the collision backoff time period during which retransmission of collided messages may not be attempted is computed as a multiple of a time slot S such that B+2A.ltoreq.S<2B+2A, where A is the maximum interstation propagation delay of the communication medium and B is the intrastation propagation delay of the network stations. The collision backoff time period is timed from the point at which the medium becomes quiescent following collision and transmission of the jam signal.

Abstract: A microprocessor based system for storing and monitoring articles such as the keys for the vehicles in the inventory of an automobile dealership. The keys are held on binary coded cards which are received by edge connectors mounted on four removable panels on a wall mounted storage board. Each key has an identification number determined by the code on its card, and each edge connector has a unique address. The microprocessor continuously scans the edge connectors and stores in memory the code of the key at each address. Each edge connector has an indicator light which is turned on when a valid user code is entered on a keyboard and a request is made for the key located at the address of the edge connector. If request is made for a key which is missing, the system displays the number of the key and the user code of the person who removed it.

Abstract: In a communication facility a masterstation initially directs a single inquiry signal to the aggregate of the operating stations and receives a response from this aggregate indicating by its structure which of the several individual stations currently needs service from the communication facility. Messages are thereafter exchanged between the masterstation and those stations only which need service to inform the masterstation as to the details of the needed service. The many message exchanges between the master station and individual stations needing nothing is eliminated.

Abstract: Contention among a plurality of synchronous and asynchronous devices connected to a shared communication medium for access to time slots in a sequence of frames is resolved by assigning a unique priority word including a priority code prefix to each device and granting access to a given slot by comparing the values of the priority words assigned to competing devices. The priority code prefix is assigned as a joint function of whether synchronous or asynchronous communication is desired and whether synchronous communication is being initiated or continued. In each assignment protocol, synchronous communication is enabled by assuring any device that initially gains access to a particular time slot continued access to the same slot in succeeding frames. If desired, devices with synchronous access may relinquish unused time slots to asynchronous traffic, while reserving the ability to resume synchronous communication.

Abstract: In a distributed computer control system in which remote stations are interconnected by a communications link, the remote stations take turns having supervisory control over the communications link. Each remote is numbered in sequence in a predetermined succession order and takes its turn having control of the communications link in accordance with this succession order. When a remote station has completed its turn of having supervisory control, it transmits a first control message over the communications link. The next remote station in the succession order then takes control over the communications link by transmitting a second control message over the communications link. Each remote station has two variable timers which are set in response to the first control message and the second control message, respectively, and have time out intervals depending upon the offset of the receiving remote station from the remote station which transmitted the control message.

Abstract: A communication system comprises several transmission bus segments (A . . . G) to which data stations (ST) are attached. Node units (1 . . . 7) are provided for interconnecting the bus segments which are selectively activated in a predetermined sequence for authorizing message transmission by attached data stations according to any given access protocol. Thus, only small groups of stations contend for access, but all messages are distributed over the whole network. Activation of a bus segment is effected by an authorization message from an assigned node unit. A token message is used to pass the status enabling a node to activate its assigned bus segment, sequentially through all nodes of the network. Each node unit comprises a control unit (17) for sending and receiving token messages and segment activation messages, and further comprises unidirectional amplifier means and switches (11) for establishing a connection between two associated bus segments selectively in either direction.

Abstract: In a programmed logic array (PLA) having a crosspoint AND plane and a crosspoint OR plane, each of these planes has input lines and output lines intersecting at crosspoints across each of which a transistor driver is connected or not, depending upon the details of the desired logic transformation function of the plane. Each output line is connected to a separate clocked pull-up (or precharge) transistor for precharging that line, and the source terminal of each driver is connected to a clocked pull-down transistor for logic evaluation or computation. In order to reduce the time needed for precharging, the source terminal of every driver is connected to another clocked pull-up transistor.

Abstract: This invention has as its object an infrared emitter. The case of a remote control device has a cover (14) doubly hinged around an axis (X--X) around which it can swivel to carry out the push button function that makes possible the activation of an infrared emitter in the case. The case is also hinged around a movable second axis of articulation (Y--Y) around which it is made to rotate when it is desired to replace the direct current power source (18) which is attached to the cover (14). The locking and unlocking means for the opening of the case by swivelling of the cover (14) around the second axis of articulation (Y--Y) consists of the hinge pin (50) of the hinge (42) that defines the first axis of articulation (X--X) of the cover.

Abstract: A two-stage, rearrangeable multiconnection switching network for connecting N.sub.1 input channels to n.sub.2 output channels. The network comprises a number of first stage switches and a second stage switch, e.g., rectangular arrays. The second stage switch has n.sub.2 outlets each connected to one of the n.sub.2 output channels. A connection arrangement connects each of the first stage switch inlets to an associated predetermined input channel such that for any group of n.sub.2 of the input channels, there is a group of n.sub.2 of the first stage switches each having one inlet connected to a different one of that group of n.sub.2 of the input channels. The approach is easily extendible to switching networks serving any larger number, N.sub.2, of output channels by adding second stage switches and connecting each additional second stage switch to each first stage switch. In larger networks, the first and second stage switches are themselves replaceable by two-stage networks in accordance with the invention.

Abstract: A device for detecting the presence of an alarm tone of a given frequency within a received signal carrying digital data in addition to said tone. The receiver comprises an analog-to-digital converter (42) the output of which is applied to a first recursive bandpass filter centered at the frequency of the alarm tone and the feedback loop of which includes a limiter. In addition, an input feedforward loop is provided for adding (at 58) the output signal from the converter (42), as multiplied by a coefficient .gamma., to the output signal from the limiter. The output signal from the adder (58) is hard limited (at 44), then passed through a second bandpass filter. The energy of the signal obtained at the output of said second filter is then measured to provide indication of a tone's being received when said energy exceeds a predetermined threshold.

Abstract: A precision fathometer interface adaptor for interfacing a shallow and a p water sonar with a computer operated survey system for a 20-line to 16-line data selector is coupled to a multiplexed 16-line data bus. Two sources of bathymertic data are input to the data bus. For 5-bit BCD the four MSD or LSD are selected for input. The output is selected by three operational modes: Select Source 1, Select Source 2 or Automatic. The Automatic mode selects the bathymetric data output for the computer according to the water depth. An externally activated timer generates time/event markers for external devices.

Abstract: A distress light and signal system including a light adapted to be anchored in the ground in proximity to a road passing by a house. The light includes a switch for selectively actuating the light in an emergency from within the house and is powered by a solar collector and a rechargeable battery. Information is retained at a location remote from the house including directions for use by a person responding to the emergency. The system includes immediate retrieval of the information upon notification of the existence of an emergency at the house. With these features, a person responding to an emergency may reach the house rapidly by visually locating the light upon reaching the vicinity of the house.