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.

Abstract: A wiring base for a bar code scanner or the like provides a conductive housing open at one face for connecting cables at various screw terminals to a circuit board providing signal processing for the signals and permitting various different-connections of the cables. The shields of the cables pass into the conductive housing to be terminated on conductive housing thereby enlisting the conductive housing as a shield around all the cables. Attachment of the scanning head to the upper face of the wiring base closes the housing to be free from the egress of dust or liquid and completes a Faraday cage around the connections while connecting two multi-pin connectors one within the base and one within the scanner, communicating the signals to the scanner. A visual indicator attached within the conductive housing indicates the presence of power and its polarity prior to connection of the scanning head to the conductive housing.

Abstract: An electric motor has three windings which are supplied by a three-phase source of electricity that has one polarity during a first half-cycle and another polarity during a second half-cycle. The motor is controlled by an apparatus that has three thyristor switches coupling the phases of the source to the motor windings. A switch controller triggers the thyristor switches to apply electricity that produces movement of the motor. One thyristor switch is operated to be in a first non-conductive state during a portion of every first half-cycle and in a second non-conductive state during a portion of every second half-cycle. The first non-conductive states are longer in duration than the second non-conductive states. A current sensor provides a first value that indicates the magnitude of the DC component of electric current flowing through one motor winding that is connected to the one switch.

Abstract: A bar code reader of the type which directs a light beam to scan an area (i.e. raster scan) is disclosed herein. The reader includes first and second oscillating mirrors for directing a light beam from a photodiode to a bar code, and for directing portions of the light beam reflected from the bar code back to a photodetector which generates an electrical signal representative of the information embodied in the bar code. The first oscillating mirror scans the light parallel to a first line (e.g. vertical line) at a first frequency onto the second oscillating mirror. The second oscillating mirror scans the light from the first mirror parallel to a second line (e.g. horizontal line perpendicular to the vertical line) at a second frequency greater than the first frequency onto the bar code. The first mirror may be a compound mirror having a concave, reflective surface which circumscribes a flat, reflective surface.

Abstract: A non-invasive system for accurately determining the stator resistance in an electric motor during motor operation. The system includes a mechanism for determining the phase angle of the stator current within the dq frame of reference and a mechanism for transforming feedback voltages into a new frame of reference defined by this phase angle. Counter EMFs are detected which are free of stator resistance and used to force the counter EMF components of the stator winding voltages to conform to desired values. The stator resistance is then derived using simple mathematical relationships between the resistance, stator current, feedback voltage and known counter EMF values.

Abstract: A method and apparatus for incorporating fuzzy logic into a feedback controller is provided. An error signal and the derivative of feedback or error is provided to the fuzzy logic to develop a proportional and differential signal, the differential signal is subsequently integrated and added to the proportional signal to create a control output of the controller. The fuzzy rules of the fuzzy logic decrease the integral term under situations that might lead to "wind-up".

Abstract: A method and apparatus for motor control tuning wherein an extremely accurate estimate of inertia is determined by using the second derivative of a desired motor velocity and the torque supplied to a motor is altered as a function of inertia.

Abstract: A programmable controller for executing general instructions and relay ladder instructions employs a general purpose microprocessor together with a high speed relay ladder processor. The relay ladder instruction in a user program are executed by the special processor exclusively. When a general instruction is encountered, the special processor releases the general purpose microprocessor from a wait state and provides it with data in response to a previous long read instruction. This data is interpreted by the microprocessor to indicate the next instruction to be executed and points to a series of machine instructions terminating in another long read instruction to a designated address. When a read of this designated address is detected by the special processor, thus indicating the conclusion of the execution of the general instruction, the special processor puts the microprocessor back in the wait state and continues to execute relay ladder instructions in the user program if any.

Abstract: A node circuit is operative to couple Manchester encoded data between a transmission medium and an associated electrical device. A first mechanism detects a message frame preamble having a pattern of alternating signal level of substantially identical duration, and a second mechanism that detects a start delimiter in the message frame. The start delimiter has a plurality of binary signal levels in a unique pattern that satisfies a defined set of criteria to optimize the probability that the pattern will be detected while minimizing the likelihood that random valid data will alias into the start delimiter pattern. A data decoder is provided to convert the Manchester encoded data into binary data which then is sent via a signal path to the associated electrical device. Another mechanism is included to detect a unique end delimiter that signals the termination of the message frame.

Abstract: A motor control system and the electrical bus for interconnecting the components of the control system are disclosed herein. The system includes a main motor control unit connected to four motor axis control modules. The control algorithms and commands for the system are stored and executed by the control unit which communicates control commands to the individual motor axis control modules. Each motor control module processes the control commands to control a motor connected to the module, and also communicates feedback signals produced at the associated axis to the control unit. The interconnection between the control unit and the modules is positioned at the face of the components to facilitate removal and insertion of the modules. The electrical bus includes both communications conductors and power conductors, and is included in the interconnection of the components.

Abstract: Activity on a digital communication network is divided into periodic intervals, that are further subdivided into first and second phases during which different classes of data are transmitted. A media access controller for a station on the network has an interface that connects to an external device which supplies first and second classes of data for transmission over the network. A first memory stores the first class of data and a second memory stores the second class of data. The external device supplies a third class of data that may be transmitted over the network during either the first or second phases. The third class of data is held in a third memory. A transmitter connects the three memories to the interface in order to send data over the network. A control circuit regulates the transfer of data from the memories to the transmitter, with data being transferred from the first memory when the media access controller has access to the network during one of the first phases.

Abstract: A method and apparatus to be used with a motor controller for determining the degree of rotor winding failure and stator winding failure using current zero crossing times of the stator winding currents. An error signal sequence, consisting of phase angle errors between consecutive zero crossings over a sampling period, is generated and analyzed in different regions of interest in either the time or frequency domain, producing signals with varying amplitudes, the signal amplitudes together with other motor parameter measurements being used to determine the degree of rotor winding failure and stator winding failure.

Abstract: A bar code reader and the mirror oscillating system thereof are disclosed herein. The bar code reader is of the type which produces a scanning light beam by oscillating at least one mirror with a electromagnetic oscillator. The electromagnetic oscillator includes a winding which is energized with an alternating current signal produced based upon a position signal generated by a magnetic pickup. The position signal is representative of the location of the mirror. The position signal is amplified, phase-shifted, and assigned a duration based upon the difference between the desired angle of mirror oscillation and the actual angle of oscillation to produce the alternating current signal which is applied to the winding. When applied to the winding, the alternating current produces an alternating magnetic field which interacts with a permanent magnet fixed relative to the mirror to oscillate the mirror.

Abstract: A module interfaces a programmable controller to several serial communication networks over which data may be exchanged according to different protocols. A module has a central controller and a separate port circuit for each of the networks. Each port circuit includes a microprocessor and a shared memory to which both the central controller and the port microprocessor have access for the exchange of data. The central controller transfers data from the shared memories to a module output coupled to other components of the programmable controller. A removable memory cartridge stores a plurality of programs for execution by the port microprocessors to exchange data over the networks using different communication protocols. Configuration data is stored in the module defining which program is to be transferred from the memory cartridge into the shared memory of each port circuit.

Abstract: A mounting for a single in-line package (SIP) module includes an elongated slot aperture for receiving an edge of the module. The module may be a circuit board or other electrical device and preferably includes edge finger connectors. The elongated slot aperture preferably includes hemicylinders located about the periphery. The hemicylinders provide plated through conductors for connecting to the finger connectors of the module. The aperture is made according to an advantageous method in which the aperture is etched in order to remove barbs or extra copper material caused by milling the aperture. Preferably, the module fits into the aperture with an interference or size-on-size fit. The aperture may include strain relief areas.

Abstract: A capacitor precharge circuit limits both peak DC link current and peak AC line current to any desired peak magnitude thereby providing for optimum precharge control and robust operation. The precharge circuit employs a microprocessor which implements a non-linear discontinuous current control scheme without the need for current sensors. The precharge circuit is well suited for use with an AC to DC converter having link inductor and a DC bus capacitor which requires precharging before full power is applied to the converter.

Abstract: A "navigation protocol" is implemented via a computer program to provide communication and invocation capability among object-oriented application programs and precompiled library routines, collectively referred to as `programs`. Each application program is "registered" with the operating environment during its installation; registration entails updating a registration-table data structure with information about 1) a program identifier; 2) an object-type identifier identifying a class of objects; and 3) an action identifier, e.g., a menu entry, identifying an action which the program can perform on objects of the class specified by the object-type identifier. A user can manipulate an object by selecting the object and requesting that a list of all actions performable on the object be displayed, then selecting one of the displayed possible actions.

Abstract: An industrial controller I/O module includes on-board programming 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 programmable logic circuits are programmed by the microprocessor on power up by reading configuration data from the PROM and writing it to the logic circuits to define their I/O circuit functions in controlling the I/O drives on a controlled machine or process.