Abstract: A control system for controlling the temperature within process machinery such as the feed assembly in an injection molding machine. The control system provides a six phase process for starting up the machine from cold conditions and controlling the machine temperature to rapidly and accurately attain a command temperature while identifying control parameters for use under steady state conditions for maintaining the command temperature.

Abstract: A method of fine tuning the "gain" of a fuzzy logic controller, the controller having input and output membership functions where the input membership functions receive one or more inputs and are grouped in sets according to each input, where the gain is tuned by uniformly scaling the domains of one or more of the sets of the input membership functions.

Abstract: A transformer-coupled, bridged-T network for connection of a load to an electrical communication network includes a transformer with a center tap and two end taps, a drop cable for electrical connection of the load to the center tap and passive elements connected across the transformer to compensate for impedance of the drop cable and the load when the load is connected through the drop cable to the center tap

Abstract: Multiple motion controllers for controlling servo motors are connected by a digital communications link so that controlled axes of the motion controllers may be slaved together regardless of their physical proximity. A given controller broadcasts position or command signals on the communications link in response to a request report message from any another controller. A second request report message may stop the broadcasting to conserve link capacity. Time shifting implicit in the link messages is corrected by estimating the velocity of the master axis and extrapolating the position to the local axes' time of updating.

Abstract: A communication circuit sends asynchronous digital signals in parallel to an external device. A first parity circuit in the communication circuit computes a first bit which indicates the parity of the control signals. This first bit is sent to the external device. When the digital signals and the parity bit are received by the external device, a first control signal is produced when each of the received digital signals has the same logic level for a defined period of time. A second parity circuit produces a second control signal when a parity error is found in the received digital signals. An error signal is generated in response to the presence of both the first and second control signals.

Abstract: A programming aid for troubleshooting real-time motion control programs controlling servo motors employs a graphical control language in which functionally related groups of instructions are represented by icons displayed on a programming terminal and interconnected by sequence lines to indicate the order of the instruction's execution. The programming terminal receives the address of the instructions being executed and identifies this address to a displayed icon to modify the icon thus indicating the internal operation of the program on a real time basis with little interruption of the control process.

Abstract: A real time three-phase analyzer stores digitized values of the signals of the three-phase circuits in memory so that they may be addressed according to circuit and sample number. Positive, negative and zero phase sequences are developed without the need for trigonometric calculation by combining samples offset in memory by a number of samples approximating 120.degree.. That number of samples may be determined for an arbitrary frequency of the three-phase system by identifying zero-crossing points of one such signal and assuming the number of samples equates to 360.degree. of phase of that circuit. The phase sequence of the three circuits necessary for the calculation of the positive, negative and zero phase sequences may be determined by comparing the relative position of positive going zero-crossings for each of the three circuits.

Abstract: A fuse blown detection circuit for use in conjunction with the control transistor output circuits of a programmable controller which provides low leakage after the fuse is blown. The detection circuit comprises a pair of voltage dividers and a diagnostic triggering device forming an H-bridge network connected across the terminals of the fuse and a blocking diode. When the fuse is blown the voltage levels defined by the dividers change to activate the trigger device and enable a diagnostic signal indicative of the fuse blown condition while the blocking diode prevents current flow back through the control transistor and output circuit.

Abstract: A modular product assembly platform which includes a multiple number of industrial robots or other similar assembly devices which are removably mounted on a specially designed platform deck. The product assembly platform also includes a programmable controller system housed in a logic control cabinet, a vision control system housed in a vision control cabinet and a set of robot controllers which operate together to control the robots or assembly devices for performing product assembly tasks. The mechanical layout and configuration of the platform and the control equipment provide for convenience and flexibility in configuring and reconfiguring the assembly platform for different assembly procedures associated with different products.

Abstract: A system for filtering electrical signals and cancelling large amplitude disturbance events contaminating such signals which might otherwise interfere with these signals being further processed. The system includes a disturbance filter which is operative for identifying disturbance events and passing an inverted signal corresponding solely to these events to a summing junction for use in cancelling these events as they occur. In the preferred embodiment this system is adapted for use in a bar code reader.

Abstract: An operator interface for a photoelectric control unit including a graphical display having a plurality of icons corresponding to different control functions and a numerical display for indicating parameter settings and operating margin values. The operator interface allows the user to rapidly and conveniently reconfigure the control unit for operation in a number of different modes in accordance with a number of different operational settings. Furthermore, the interface provides information on the operating margin of the photoelectric control unit which can be useful to the operator in aligning the unit and in judging conditions under which the unit is operating. Furthermore, the operator interface allows the user to select different light pulse repetition rates and corresponding operating ranges for the photoelectric control unit.

Abstract: A dual phase resolver to digital converter having two separate channels for generating rotor position data. The first channel generates an indication of rotor position based on a sinewave type reference signal applied to a first stator winding and the rotor signal while the second channel provides an indication of rotor position based on a cosinewave type reference signal applied to the second stator winding and the rotor signal. Logic circuitry associated with the data channels provide separate fault data indicative of when position data may be subject to error. The data from the two channels are selectively combined in the output of the converter. Data from one channel is used when the other channel is subject to fault. An average of the data is used when both channels are operating properly in order to provide greater accuracy.

Abstract: A harmonic compensator comprises a transformer having low leakage reactance connected between a utility and a load and a signal generator which injects into the transformer a signal having a frequency which cancels undesirable higher order harmonics induced by the load. The low leakage reactance nature of the transformer permits injection of high frequency signals which restore the fundamental sine wave of the signal from the utility and thereby eliminates undesirable nonlinear harmonics which cause up-line disruptions. The low leakage reactance transformers may comprise a coaxial structure having a thin hollow tube as the primary coil, a coaxial structure having a single main coaxial cable distributed into several paralleled coaxial cables of smaller diameter, or a co-planar transformer structure having flat strip line conductors wrapped around a conventional core as the primary and secondary coils.

Abstract: An apparatus for providing an indication of the operational stability of a photoelectric control unit. The system separately measures photoelectric operating margin and background noise affecting the control unit. A stability figure is generated as a function of the operating margin and background noise in accordance with fuzzy logic techniques. An indication of the level of this stability figure is provided to the operator of the unit.

Abstract: A mechanism for an overload relay or the like employs a contact bar that is held in a reset position by magnetic attraction and in a tripped position by the biasing of a spring. The magnetic attraction effective in the reset condition may be overcome by a countervailing magnetic field developed by a coil driven in turn by overload sensing circuitry, or by the mechanical displacement of the contact bar away from the reset position by any small amount. Resetting is accomplished by another magnetic linkage which also may be subject to the countervailing field of the coil to prevent resetting during an overload condition.

Abstract: An AC motor drive includes a PWM voltage inverter which is responsive to voltage commands from a synchronous current regulator to control motor armature current and rotor speed. A feedforward voltage is also applied as input to the PWM voltage inverter and it is compensated to boost the effective gain of the inverter when it is operated in the pulse dropping region. The compensation values are precalculated and stored in a table from which they are read during drive operation.

Abstract: A target acquisition system for a photoelectric control unit which helps avoid interference problems due to optical and electrical noise. The system provides for the interpulse interval between light pulses transmitted by the photoelectric control unit to be varied in accordance with pseudo-random jitter factors during the target acquisition process. Noise which may be on frequency with the normal repetition rate of the photoelectric control unit is then eliminated from the detection process pursuant to synchronous detection procedures.

Abstract: A programmable controller stores and executes a directed sequencer program that responds to the status of input devices and controls a machine having actuators which move a member into a plurality of positions along a linear axis. An apparatus for programming the controller to execute the directed sequencer program comprises a manual data entry device and a monitor for displaying information to a user of the programmable controller. The programming apparatus enables the user to create a graphical behavior profile on the monitor which depicts operation of the machine when the member is in each position. The user also is able to designate whether each of the actuators is to be activated when the member is located at each of the positions, and the status of each input device when the member is located at each of the positions. A indication of one of the plurality of positions at which the member causes the controller to send a signal to the output also is displayed on the monitor.

Abstract: A programmable controller senses the status of input devices and controls the state of operating devices in accordance with a stored ladder logic control program. A memory of the programmable controller contains message data and data defining a set of expected transitions of the status of selected input devices. An instruction of the ladder logic initiates execution of a machine language message program which causes the programmable control to inspect the states of the selected input devices to determine whether an expected transition has taken place. When one of the expected transitions occurs, the message data and an identification of the selected input device are sent to a personal computer connected to the programmable controller. The personal computer uses the the data from the programmable controller to formulate an alphanumeric message which is presented to the operator on a display device.

Abstract: A machine is controlled by a system which has a pair of programmable controllers connected in tandem. One controller operates in the active mode governing the operation of the machine, while the other controller is in a backup mode able to assume control of the machine should the active controller fail. Each programmable controller has a backup module through which the two controllers are connected. In order to determine which controller is to be active upon power up, each backup module has an input means for receiving a first active mode request signal from another programmable controller. A means is provided to produce a tie breaker signal at one backup module which indicates that its programmable controller is to operate in the active mode when both programmable controllers simultaneously desire to operate in the active mode.