Abstract: To perform call control signaling between a user and a telecommunications switching network (and end-to-end between users), a portion of the multiplex overhead of a multiplexed data stream is formatted so that it includes the call control signaling. This in-band signaling is actually in the multiplex overhead and not in the user data as in standard multiplex formats. At nodes of the network and at user devices connected to the network, the call control signaling is extracted from the overall data stream and is processed to selectively generate new and responsive call control signaling for completing the signaling operations. The invention is useful over the entire multiplex hierarchy.

Abstract: A long distance telephone switching system is adapted to provide various enhanced subscriber services, such as an audio news and information service, conference calling, voice messaging, message storage and forwarding, and speed dialing, in addition to conventional long distance calling. Additional improvements include the use of prerecorded opening and closing scripts to facilitate the handling of operator-assisted calls, the retrieval of stored subscriber billing data prior to each call reorigination in order to detect instances of possible abuse, and the concatenation of subscriber-input authorization codes with access number data to allow the use of shorter authorization codes by the subscribers.

Abstract: The invention is an adaptive method and apparatus for telephone call reorigination (i.e., the placement of successive calls without extended re-dialing). It allows shorter, uniform DTMF reorigination requests or commands to be recognized and responded to during certain stages of a call while preserving a filtering effect to avoid "talk off" reorigination during the call's talking stage. In the initial stage of a call, prior to verifying the caller's authority to place the call, a first mode of request detection, responsive to short duration tones is used. During call setup and prior to answer by a called party, a second mode of detection is used which is also responsive to short duration tones. In the talking stage, another mode of detection is used to avoid inadvertent reoriginations due to spurious tones. In one aspect, a dial tone is automatically returned to the caller upon called party disconnect.

Abstract: A threshold detection circuit is provided for determining when a data input signal exhibits an amplitude which exceeds a first programmable threshold level, is less than a second programmable threshold level or between the first and second levels. Respective scaling circuits scale down the data input signal and a line voltage signal which is supplied to the circuit to generate a scaled data input signal and a scaled line voltage signal. The threshold detection circuit scales the first and second threshold levels by a predetermined factor. The scaled data input signal is compared with the scaled first and second threshold levels. In response to this comparison, the output of the circuit assumes a first logic state when the data input signal exceeds the first threshold level and assumes a second logic state when the data input signal exhibits an amplitude less than the first threshold level. The comparison is repeated for the second threshold level.

Abstract: A data sharing mechanism employs a broadcast bus communication system to physically interconnect various control and monitoring nodes that cooperate in controlling a physical process. Shared, or global, variables are exchanged between connected nodes via a global data service provider and protocol. The protocol allows global variables to be addressed by symbolic names with multiple namespaces for the names. Additionally, the protocol allows data to be formatted with special identifiers such that once a variable name has been located in a message from a specified source, and other messages from that source with the same identifier are received, they will have the named variables in the same relative locations. The receiver can therefore directly index to the named variable when the source and identifier are known.

Abstract: The invention disclosed is useful in an I/O system of a programmable controller and provides a method and circuitry by which control and diagnostic information is exchanged between a control unit of an I/O module and a plurality of input/output points thereof. A control signal is generated in the control unit in the form of sequential pulse frames such that the control information is defined by a series of pulse width modulated pulses. Each frame includes a no-pulse time period following the review of pulses to mark the end of a frame. Each I/O point receives a control signal of its own and generates a clock pulse in response to each pulse. The clock pulse initiates a sampling of the corresponding pulse and simultaneously initiates return of a diagnostic signal value to the central unit. Thus, the control signal provides for sampling of its own content and provides for a return of a diagnostic data bit for each control bit.

Abstract: The invention disclosed provides an intelligent input/output system for a programmable controller and includes a plurality of input/output (I/O) modules, each of which may be located in proximity to the process being controlled. Each module is interconnected, via a communications link, to a central processor unit (CPU) through an I/O controller. Each module is made up of a plurality of input/output circuits and each may be selectively operated as an input circuit or as an output circuit. The selection is preferably under control of the CPU. Each I/O module includes an operations control unit for controlling each I/O circuit and for providing an exchange of diagnostic and control signals between each I/O circuit and the I/O controller and CPU. Communications between the operations control unit and each I/O circuit is preferably carried out via a pair of conductors, one conductor of which conveys a set of recurring control signals (e.g.

Abstract: A connecting apparatus is provided for removably attaching a first member to a second member. The first and second members include respective mating surfaces which mate with each other. A pivot arm is situated adjacent one end of the mating surface of the first member. A jack screw is retained adjacent the remaining end of the mating surface of the first member. The jack screw includes a threaded end which extends from the mating surface of the first member and which faces the second member. The second member includes a pivot structure adjacent one end of the mating surface of the second member. The pivot structure of the second member permits the first member to pivot about the pivot structure when the pivot arm of the first member is removably engaged in the pivot structure. A screw captivating structure is situated in the second member for captively engaging the jack screw when the mating surface of the first member is pivoted toward and mated with the mating surface of the second member.

Abstract: A keying apparatus is provided including a key support structure having a plurality of protrusions which mate with a corresponding plurality of recesses formed in an edge surface of a printed wiring assembly. The key support structure includes a mechanism for permanently latching the key support structure at a predetermined location on a mounting rail adjacent a backplane interconnect. The printed wiring assembly is conveniently removable from the key support structure. This keying apparatus assures that when a printed wiring assembly is removed from the key support structure at a predetermined location on the rail, only the proper printed wiring assembly may be reinserted at that location.

Abstract: A method of determining access on an electronic serial bus by implicit token passing. The serial bus receives and transmits data between a plurality of devices. Each device has a receiver for receiving data to the serial bus, a transmitter for transmitting data to the serial bus, a bus idle timer for detecting an idle condition on the bus, and a bus access timer for controlling access to the serial bus. Each device is assigned a unique bus address. The bus access timer of each device is loaded with a value representative of each device's own unique bus address and the unique bus address of the transmitting device. The bus access timer starts a count upon receiving an end of transmission condition from the transmitting device and stops upon receiving a start of transmission condition from the transmitting device. When a bus access timer of a device reaches a predetermined value, the device of the timed out bus access timer is given access to the bus.

Abstract: A method is disclosed for determining the operability of a switching device controlling an electrical load and the status of the load as open, shorted, or normally connected, without disruption of the operative state of the load. The method includes the steps of: (1) commanding the switching device to switch the load to the opposite state for a momentary period less than required for an actual change of state; (2) measuring electrical responses as an indication of the operability of the switching device and the status of the load; and (3) repeating the momentary switch of the load for increasingly longer periods of time until the status of the load is determined or until the momentary time period reaches limiting time duration.

Abstract: The disclosed invention provides manually operated apparatus for precise placement of surface mounting integrated circuit devices on a printed circuit board. A dispensing unit operates to position a device into an oriented, predetermined position with respect to a first reference member, and a hand-held pickup unit is manipulated to pick up the positioned device from the dispensing unit while fixing its position with respect to a second reference on the pickup unit. The device in the pickup unit is transferred to and placed upon a prepared printed circuit board. The device is maintained in the same position relative to the two references and the desired placement points on the printed circuit board.

Abstract: A method for controlling an articulated robot manipulator with an offset wrist made with only rotary joints. The method relates to transforming a given position and orientation of the robot tool or end effector in Cartesian space to the equivalent joint angles of the robot. Commands generated from the joint angles are sent to actuators connected to the rotary joints, where the desired motion of the robot tool is generated. This method of transforming a point in Cartesian space to joint angles is accomplished by providing a cross-product and dot-product recursive methods that employ the robot geometry to determine the location of the the end effector, such that the computational complexity of the techniques allows real-time computations for current state of the art microprocessors.

Abstract: Color is added to the standard video display (18) of a computer numerical control system for controlling the operation of a machine tool (10) in the performance of specified operations with respect to a workpiece. Color assignment records (62) are included in the machine setup data (MSD) source file (54) for implementing background color, reverse video color, forms character color, data character color, errors and/or alarm color, operator required response color, and high-lite color. The MSD source file (54) is processed to generate a binary MSD file (56) which is then read into the numerical control basic (NC) software (24) which operates to generate both text and graphic displays. The original or default color assignments may be dynamically modified or changed through an MSD file editor (58).

Abstract: Input/output circuitry is disclosed for use in an I/O system of a programmable controller. The circuitry is protected against overcurrents without the use of fuses or circuit breakers, and is automatically restored to normal operation following correction of an overload condition. Diagnostic signals are produced for monitoring the operating condition of the circuitry. The invention includes an insulated gate transistor (IGT) having a main current section carrying a majority of the load current and an emulation section which carries a fractional portion of the load current. The emulation section current tracks the total current at all times. A current sensor monitors the emulation section current and provides a signal representing the instantaneous load current. This signal is continuously compared with preselected reference levels to derive a set of diagnostic signals that are indicative of the operating condition of the circuit, and whether output loads are open or shorted, for example.

Abstract: A method for defining and executing customized canned cycles for a numerically controlled machine in which the end user or original equipment manufacturer can define a sequence of actions or tasks to do precisely what a particular application warrants. The customized sequence of tasks can be subsequently edited or modified or desired. A set of executable tasks capable of being carried out by a machine are defined with an assigned number associated with each task. The desired customized sequence to be performed by a canned cycle command code is entered by the user into memory. A part program containing the command code is loaded into the computer numerical control. The command code is processed to retrieve the desired customized sequence of tasks from memory. The desired tasks are then executed in sequence to cause the commanded action in the controlled machine.

Abstract: The invention disclosed provides circuitry which is selectively operable either as an input point or as an output point in a programmable controller having multiple input and output points for exchanging signals between a central processing unit (CPU) of the controller and a process being controlled. Preferably, operation as an input point or as an output point is under control of the CPU. The invention includes a common input/output terminal for terminating both input and output devices; an input return terminal for terminating a return conductor from the input device; an output return terminal for terminating a return conductor from the output device; a preload resistor connected between the input/output terminal and the output return terminal so that a status signal is developed across the preload resistor indicating the status (generally, open or closed) of the input device; and an insulated gate transistor (IGT) connected between the input/output terminal and the input return terminal.

Abstract: A method is disclosed for machining multiple entry threads on a workpiece. The preferred steps of the method are preferably carried out in conjunction with a computer-based numerical control system. The method includes the steps of: determining the angular position of the workpiece as it is being rotated by a machine tool spindle; determining the desired separation of thread entry points; specifying the angular position of the workpiece at the start of tool motion for cutting a first thread on the workpiece, the angular position being stored as a reference angle; and for each subsequent thread, starting motion of the cutting tool from the first thread starting point whenever the angular position of the workpiece is displaced from the reference angle by an amount equal to the desired entry point separation from the first entry point, the motion being maintained along the identical path used to cut the first thread.

Abstract: An interfacing system for selectably interfacing signals to a computer, or other control apparatus such as a numerical control system, from either of alternative transducers which provide position indicative signals differing in format. A system according to the invention is useful for interfacing signals to a control system from either a resolver or an encoder and includes a digital counter whose output count, irrespective of the transducer type, is indicative of the monitored object's position. A data latch connected between the control or receiving instrumentation and the counter holds a count at an appropriate time and then provides a transfer of the position indicative count to the receiving instrumentation. Circuitry is included for automatically causing the counter to function as a reversing counter or as a reference counter, depending on the type of transducer signals to be interfaced.