Abstract: A circuit interrupter provides a conducting path between two conductors and interrupts the conducting path in response to overcurrent conditions in the conductors. The interrupter includes a magnetic core around which the conductors are disposed. Each conductor is electrically coupled to an arc runner and a spanner is biased into contact with the arc runners to compete a conducting path between the conductors. A secondary response mechanism is provided adjacent to the core and includes arms extending around the core and a magnetic body. In response to overcurrent conditions of a first magnitude the body of the secondary response mechanism is attracted to the core causing the arms to displace the spanner out of contact with the arc runners. In response to overcurrent conditions of a second magnitude, such as due to direct short circuits, the spanner is repelled rapidly to a non-conducting position and the secondary response mechanism is attracted to the core to hold the spanner in the non-conducting position.

Abstract: The base plate module of an electromagnetic switching device, specifically a contactor, is mounted on a base plate (1). The base plate module contains the core (2) of the electromagnet, a magnet coil (5), a printed circuit board (10) with its connected ancillary devices, as well as the contact plugs (16, 17) and terminals (24, 25), both of which are accessible from the outside. Printed circuit board (10) is mounted on base plate (1) and is located between base plate (1) and core (2), which is mounted on the base plate. Strip conductors (12, 13, 14), on the side facing core (2), feature several spring-loaded stub contacts (19, 20) and/or contact plugs (21, 22), all of which are vertically mounted on circuit board (10). Flange (7) of coil module (6), which is oriented toward base plate (1), provided with terminals (23) of magnet coil (5). With magnet coil (5) in the mounted position, terminals (23) of magnet coil (5) are in contact with the spring-loaded stub contacts (19) of strip conductors (13).

Abstract: A hybrid active filter shunts three-phase power with passive elements tuned to have low impedance at a frequency of harmonic distortion. The passive elements are in series with controlled voltages sources providing cancelling currents to the harmonic currents. Rapid determination of the harmonic currents is provided in real-time through the use of a Park transformation reducing the variables which need to be manipulated. Measured currents as transformed are used to model undistorted current based on an average power consumed by the load. When the undistorted current is subtracted from the actual current, a harmonic current signal is produced that may be used to drive the voltage sources. The time domain method requires rapidly computed running averages and thus may be performed in-between the acquisition of the measured current samples.

Abstract: Subprograms together making up an industrial controller program are encapsulated in shells which make explicit the connection relationships and data flow directions of the subprogram normally implicit in the sharing of variables. The shells also identify the consumer/producer relationship of the variables as may be used to identify data contention problems. Actual connections between subprograms along which variables may be shared are externalized in a connection database that permits ready cross-referencing of such data sharing. Connection information stored in the shell may be used when a shell is cut and pasted to provide an initial suggestion of how to connect the new pasted shell. The automatic reconnection of the pasted shell refers to the previous connections and makes use of a hierarchical arrangement previously determined by the programmer reflecting the logic of the program.

Abstract: The present invention provides an efficient method of transferring multi-word data across a fixed width parallel bus normally transmitting a single word at a time by allocating part of the bus word to the transmission of a fractional address dividing the given addressing space into subaddresses or "fractional addresses". A data transfer request provides the desired fractional address and the data transfer response returns the fractional address value and the portion of the multi-word data corresponding to that fractional address.

Abstract: An industrial controller Input/Output module includes on-board processing circuitry in the form of a microprocessor and associated memory, a first programmable logic circuit and a second programmable logic circuit connected through an isolation interface. The isolation interface is comprised of optical coupling circuits. The programmable logic circuits are programmed to provide circuitry for parallel-to-serial data conversion of 24 bits of system Input/Output data on each side of the isolation interface. The data is then transferred as serial data in both directions at once in response to a shift clock signal. The data signals and the shift clock signal utilize three one-bit optical coupling devices in the isolation interface. After transfer across the isolation interface, the system Input/Output data is converted to parallel data for further processing.

Abstract: A digital communication network carries high and low priority data. The network stations that produce high priority data are assigned to a first group of stations and stations that produce low priority data are assigned to a second group with the two group not being mutually exclusive. Activity on the network is divided into periodic intervals of the same duration. Network control information, that defines how access to the medium, is determined is broadcast to all stations during a first segment of a periodic interval. The network control information defines the length of the periodic interval and of the periodic interval segments, and defines how many stations are in each group. Then during a second segment of the periodic interval, every station in the first group is afforded an opportunity, in a predefined order, to transmit high priority data over the medium.

Abstract: A method and apparatus to be used with a motor controller for determining the speed of the motor rotor using current zero crossing times of the stator winding currents. An error signal set, consisting of phase angle errors between consecutive zero crossings over a sampling period, is generated and analyzed in a region of interest in either the time or frequency domain, producing a signal frequency, the signal frequency being the frequency of the motor rotor.

Abstract: A method and apparatus used with a motor controller that detects load imbalance at a relatively low speed and, if the degree of load imbalance is greater than a predetermined acceptable maximum degree, produces an alarm signal that indicates an imbalanced load. If the degree of load imbalance is greater than the predetermined acceptable maximum value, the present invention may either attempt to rebalance the load or stops the motor until the balance can be manually adjusted.

Abstract: A bar code reader mirror oscillator is disclosed herein. The oscillator includes a permanent magnet having first and second poles of opposite polarity and an electromagnet having a core with first and second pole locations. The permanent magnet is fastened to a mirror carrier resiliently mounted to a frame to oscillate about a rotational axis, wherein the electromagnetic core is fastened to the frame so that the poles of the permanent magnet are equidistant from the pole locations of the electromagnet. This oscillator configuration directs substantially all of the energy applied to the electromagnet to the production of oscillatory motion in the associated reader mirror.

Abstract: Activity on a digital communication network is divided into periodic intervals and during a segment of each periodic interval a moderator station broadcasts a numerical count of the periodic intervals to all stations on the network. Each station has a memory in which a numerical value is stored, and a comparator that compares the numerical value to the numerical count received from the network. When the numerical count of the periodic intervals equals the numerical value, an apparatus within the station performs a defined operation, such as transmitting a message over the network or synchronizing a clock in the station to a master time standard. The equality of the periodic interval count and the numerical value also can be used to determine when to signal an external device. By using the count of the periodic intervals in this manner, the operation of several stations on the network can be coordinated.

Abstract: A bar code reader for reading bar codes falling within a rectangular scan area having two vertical sides, a top and a bottom is disclosed herein. The reader includes two oscillating mirrors operable to scan a light beam over the area. Each mirror is oscillated by an assembly controlled by a control circuit which produces controls signals which define the rate and frequency at which the mirrors are oscillated. More specifically, the mirror which sweeps the light beam between the vertical sides of the area is oscillated at a constant frequency, and the mirror which causes the mirror to progressively sweep between the top and bottom of the area is rotated so that a greater number of sweeps occur when the light beam progresses from the bottom to the top of the area than when the light beam progresses from the top to the bottom of the area.

Abstract: A bar code reader including a dynamic damper for an oscillating mirror assembly is disclosed herein. The reader includes a frame which supports a light source for producing scanning light, and a transducer for receiving scanning light reflected from a bar code being read by the reader. The light produced by the light source is scanned over the bar code by an oscillator assembly including a carrier defining a rotational axis, a light reflector fastened to the carrier, and a spring assembly fastened to the carrier and the frame to resiliently support the carrier for oscillation about the rotational axis. A damper fastened to the frame and slidably engaged with the carrier is provided to inhibit oscillation of the carrier perpendicular to the rotational axis. Such undesirable oscillation is typically caused by forces external to the scanner such as jarring of a structure supporting the scanner.

Abstract: A system for synchronizing a plurality of motors is disclosed. The system includes a universal drive controller which can control the operation of two motors, a power module for each motor, and a power module interface rack which is utilized to interconnect the motor to its associated universal drive controller. If a plurality of universal drive controllers is involved, a common clock is utilized to synchronize the operation of same.Synchronization of the motors is achieved by monitoring the output shaft of each motor through the use of a resolver, transmitting feedback data relative to the position of the output shaft to the universal drive controller via the power module interface rack, calculation of command data by the universal drive controller to effect synchronization, and transmitting the command data to the power module interface rack wherein the power module causes the proper firing signals to be transmitted to the associated motor.

Abstract: A highly distributed industrial control system employs a number of separate control modules communicating together on a shared communications medium. Each module emulates one or more basic electrical parts having electrical terminals, such as switches and relays, and transmits production messages indicating the state of the parts, such as conducting current or not. A connection list for each part in each control module defines message identifiers of other parts whose production messages are received by the control module and interpreted as current flow to one or more of its parts. The control system is programmed by generating a schematic on a programming terminal showing connections of terminals on symbols of the parts such as would represent actual wiring of the emulated parts. A parts layout diagram is used in conjunction with the schematic to identify each part to a physical module.

Abstract: A bus bar having reduced parasitic inductance and equal current path legends. A bus bar of the present invention has a first plate connected to a collector of a first transistor, a collector of a second transistor, an emitter of a third transistor and an emitter of a fourth transistor; a second plate including a second plate input connected to a collector of the third transistor and a collector of the fourth transistor; a third plate including a third plate input connected to an emitter of the first transistor and an emitter of the second transistor; and a fourth plate which is connected to the first plate. The first plate, the second plate, and the third plate are disposed such that the lengths of the current paths from the fourth plate through the first transistor to the input of the third plate is equal to the length of the current path from the fourth plate through the second transistor to the input of the third plate.

Abstract: A harmonic analyzer using a short sampling window eliminates truncation artifacts in the sampling of an AC power waveform by equating the length of the sample period to a period of the sampled waveform. The period of the AC power waveform is estimated from the waveform and used to produce a set of "resampled" points evenly spaced within that period as estimated from the sampled. By performing a spectrum analysis on the resampled points, artifacts at the harmonic intervals are reduced to zero.

Abstract: A point-to-point soldering apparatus applies solder to predetermined points on a workpiece in response to control signals from a control circuit. The apparatus includes a heat source moveable to first locations adjacent to the solder points in response to control signals from the control circuit and a solder material source moveable to second locations adjacent to the solder points independently of the heat source in response to control signals from the control circuit. The heat source is mounted on a first robotic positioner and the material source is mounted on a second robotic positioner for independent movement and positioning. A user-programmable controller executes preset soldering routines in which the heat source and material source are positioned adjacent to solder points and commanded to apply heat and solder in accordance with the soldering routines.

Abstract: A method for providing a standard coordinated time throughout spatially separated functional modules of an industrial controller employs a module operating as a time-master which transmits a coordinated time value to various dependent modules through communication modules. The particular time-master is determined by an arbitration process among potential masters which examines a time quality value, indicating the precision of the time-master's clock, and incorporated in the transmitted synchronization signal. Upon the loss of a master or the introduction of a new master, mastership is reallocated so that the master time value is provided from that module having the best time quality. Offset caused by "ripple through" of the time value through communication modules is minimized by summing to that time value as it traverses a communication module with a time quantity measuring the processing time of the communication module.

Abstract: An optical code reader having an improved mirror support is disclosed herein. The optical code reader is of the type which scans a code with a light beam and determines the information embodied in the code by decoding signals representative of the portions of the light beam reflected from the code. The scanning motion of the light beam is produced by a mirror supported for oscillation at a predetermined frequency. In particular, the mirror is supported by a shaft which is supported relative to the frame of the reader by two sets of four U-shaped springs. One set of springs is fasted between the first end of the shaft and the frame and the second set is fastened between the second end of the shaft and the frame. This spring configuration supports the mirror and shaft for oscillation about a desired rotational axis without the use of bearings.