Abstract: An adapter response circuit indicates the number of adapters on a link responding to a given address and hence permits the detection of possible data collisions. Each adapter responding to the address transmitted on the link induces a current on a common conductor. The magnitude of the current unambiguously identifies the number of adapters responding to that address. The proper resistive termination of the link may be checked by inducing a similar incremental current on the conductor and evaluating a voltage variation indicating the presence or absence of a termination resistor.

Abstract: A flash-on reduction circuit for use in the binary state output circuitry of an industrial controller employs a current conductor to charge parasitic capacitances of the output circuitry when the industrial controller is first turned on and a current limiter for preventing high current flows through the output power stages of the output circuit when the industrial controller is first turned on. The current limiter is deactivated by a timing means after the parasitic capacitances have been charged by the current conductor. In a first embodiment, the current conductor and current limiting means are provided by a current source applying increasing power to the output circuit.

Abstract: A switch operator, such as a manual push button, mounts a latch onto which are mounted up to four cartridges. A pair of laterally opposed arms of the latch receive each cartridge between them, and lock the cartridge to the latch. Each cartridge has four lips, two for each arm, which engage a pair of spaced apart locking surfaces on each arm. Each arm fits between the two lips it engages, and each cartridge has a pair of feet which fit into a pair of pockets in the latch. A contact cartridge has a follower, and the follower and feet are both positioned to one side of the cartridge, and the feet cooperate with the pockets to insure proper orientation of the cartridge in its position on the latch.

Abstract: A programmable controller has a rack that houses and electrically connects a number of I/O modules and a processor module. The processor module includes a external communication network interface, a system memory, a processor section which executes a user-defined control program and a I/O interface that handles the exchange of data with the other modules. The I/O interface has circuitry for pre-processing data from defined input modules, thereby relieving the processing section of certain tasks. The shared memory contains information defining the input module from which to obtain data for pre-processing and the bits of that data to be examined for specified logic level transitions. The stored information also designates the frequency at which the data is to be read from the defined input module and how many occurrences of the specified logic level transitions must take place before the I/O interface signals the processor section that the pre-processing is complete.

Abstract: An autotuning procedure for a PID-type controller employs a low frequency sine wave as an exciting input and models the controlled system as a second order linear system. The system is tuned to a desired damping ratio by following an overdamped trajectory, in closed loop gain and phase lag space, to the target closed loop gain and phase lag values on a locus of a desired damping ratio as based on that modeling system.

Abstract: A collimator/aperture, in an absolute encoder, produces a line of light to illuminate the encoder's code wheel. The collimator employs a bundle of fiber optics to receive an intense and generally cylindrical beam of laser light. The opposing end of the fibers are spread in a fan and clamped between carefully dimensioned clamping surfaces to produce a line of light one fiber thick. The collimator/aperture avoids the wasted energy associated with a slit mask. The fiber optics are held parallel near their light emitting ends and the ends are polished square to the axis of the fibers to provide a high degree of collimation. Fibers with low numerical aperture further improve the collimation.

Abstract: A numerical controller accepts an instruction for the cutting of pockets with perimeters of irregular shapes, the instruction defining the perimeter by a series of vertex points and a straight-line, circular, or some other interpolation to move between these vertices. The numerical controller cuts the perimeter of the pocket by reference to the vertex points and constructs a bit map indicating the cut and uncut material after completion of the perimeter. A rule-based path generator employs the bit map to complete the interior of the pocket without explicit programming of those interior tool motions. The bit map is constructed on a real-time basis by offsetting the tool motion coordinates to roll over in the bit map space regardless of the tool starting position.

Abstract: A method for tightening threaded fasteners to any desired proportion of the way through a torque-angle specification window defined by low and high angle limits and low and high torque limits. The torque rate for the joint is determined from torque and angle measurements taken during tightening and compared to boundary ratios which are determined as the rates of change of torque with respect to angle from a threshold torque to the corners of the specification window. A final target parameter value of either torque or angle is calculated based upon this comparison which is approximately halfway through the specification window along a projection of a torque-angle characteristic curve for the fastener which is determined from the torque rate. Correction factors are also provided for tool overrun depending upon whether torque or angle control is used and a reject rate margin is employed to account for nonlinearities which otherwise may lead to unacceptable assemblies.

Abstract: A programmable controller has a rack that electrically connects a number of I/O modules to a processor module. The processor module includes a external device communication interface section and a general purpose processor section electrically coupled together by a set of common buses. Both of these module sections include a microprocessor and memory connected by an internal set of buses which are isolatable from the set of common buses. The isolation capability permits the different sections to perform their operations simultaneously. A shared system memory and an rack interface are coupled to the common buses for the exchange of data with the I/O modules. A unique ladder logic processor also is connected directly to the common buses. The ladder logic processor includes a hardwired Boolean bit logic processor and a custom microcoded processor to execute instructions of a ladder type control program.

Abstract: A programmable controller for operating a machine to perform programmed functions allows the user to allocate the amount of processing time to be devoted to a machine control program and to user defined background tasks. The allocation is defined by an entry stored in one of several locations in a data table. Each occurrence of a timed interrupt steps the operating system through the data table. When the operating system accesses the location at which the entry is stored, the machine control program is assigned as lower execution priority than any background tasks to be executed. When the last storage location of the data table is accessed, the user control program is restored to a higher execution priority than the background tasks before initiating another stepping sequence through the data table.

Abstract: An electric induction motor is connected by a switch means to a source of three-phase alternating electricity. The speed of the motor is determined by detecting when the source voltage a zero crossing and thereafter sensing the polarity of the back emf voltage induced in each winding of the motor when the switch means is non-conductive. After several zero crossings a set of polarity samples has been produced from each winding. The motor speed is determined by detected the occurrence of a predefined relationship among samples in each set. For example, the speed is in the range of fifty to about thirty-eight percent of full synchronous speed when three consecutive samples from one winding all have the same polarity. The occurrence of the predefined relationship among back emf polarity samples can be used to control the braking of the motor.

Abstract: A controller for an injection molding machine controls the injection ram by means of profiles having segments with programmable setpoints. The injection molding machine is initially controlled during each segment in an open-loop manner. Closed-loop control is then adopted. The difference between the open-loop and the closed-loop output to the injection molding machines valves is used to change the setpoints with each cycle to improve the open-loop accuracy over time. The learning rate of change of the open-loop setpoints decreases after the initial correction. During the open loop control, the closed loop control is deactivated to prevent it from being affected by the previous open loop error.

Abstract: A teaching method for a recurrent neural network having hidden, output and input neurons calculates weighting errors over a limited number of propagations of the network. This process permits the use of conventional teaching sets, such as are used with feedforward networks, to be used with recurrent networks. The teaching outputs are substituted for the computed activations of the output neurons in the forward propagation and error correction stages. Back propagated error from the last propagation is assumed to be zero for the hidden neurons. A method of reducing drift of the network with respect to a modeled process is also described and a forced cycling method to eliminate the time lag between network input and output.

Abstract: A method of manufacturing a core for an electrical inductive device. A blind hole is provided through a stack of laminations into which an oil or an epoxy resin adhesive is placed. The blind hole provides a slow release for the oil to the outer surfaces. This obviates the contamination of the outer surfaces of the coil during manufacture as in the case with a dipping procedure. When the epoxy resin adhesive is employed in the blind hole, a wicking action takes place for better fastening of the laminations together. In another embodiment of the fastening feature, epoxy resin adhesive is molded to the outside of the end piece laminations as well as through a passage in the laminations. An improved resulting core is also provided.

Abstract: Graphical editing methods are employed to construct programs in high-level graphical languages prior to compilation and operation in controllers for industrial or commercial equipment. The editing methods include process, hardware and program editing tasks for defining both process and hardware I/O points and connecting them to variables in a controller program. Each editing task has a tree graph window, a graph editing window, and a palette with rotating panels of graphical editing tools. The hardware editing taks uses two-layered icons to graphically simulate the hardware environment. A plurality of graph types are based on generalized node-vert-arc graphical elements which are special classes programmed in the Smalltalk programming language. Languages for the controller program include function block, sequential function chart and ladder diagram.

Abstract: High-level language motion control programs are downloaded and uploaded between a programming terminal and a remotely located I/O module through a peer-to-peer network and a programmable controller system processor. Automatic block transfer between the programmable controller system processor and the I/O module is executed in response to commands from the programming terminal. The programmable controller processor and motion control I/O module are modified to handle two types of block transfers, the first controlled from the user applications program of the programmable controller processor, and the second controlled from the programming terminal.

Abstract: A high speed counter employs a number of functional blocks, flexibly interconnected on a bus structure, to provide efficient and high speed implementation of arbitrary range measuring tasks. A set of independent counters blocks are connected by the bus structure to programmable comparator blocks which establish count thresholds. The output of the comparators are paired by switchable AND/OR blocks to create ranges. The division of functions by block and the interconnecting bus structure allows the structure of each counter to be effectively programmed to fit the application at hand.

Abstract: A node adapter chip for linking a node microprocessor to a serial data link incorporates a read/write circuit and an interrupt processing means to allow increased flexibility in connecting the adapter to different node microprocessors with different interface protocols. The read/write input circuit accepts dual strobe or single strobe type read/write commands and the interrupt processor accepts either conventional interrupt handling or "polled" operation for use with microprocessors that do not have interrupt capabilities. A flag multiplexer allows the controller in the node adapter to receive status information from a serial interface in the adapter without the need for extra data transfer cycles.

Abstract: An interface circuit couples a host processor in an industrial control system to a local area communications network. In includes a protocol machine for receiving and transmitting messages on the network and an interface controller which is programmed to implement one or more protocols. As a message is received by the protocol machine, the interface controller anticipates a responsive message which it writes to the protocol machine even as the message is being received. If the message is received accurately, the responsive message is transmitted without delay.

Abstract: A motor controller includes a set of thyristors which couple the motor to a source of alternating electricity. A detector senses when the voltage of the source makes a zero crossing. A mechanism is provided to vary the frequency of a clock signal at a rate determined by a user selectable input which represents the rate at which the motor speed is to change during starting or stopping. The clock signal is applied to a counter which produces an active trigger signal when a given number of clock signal cycles have been counted following a zero crossing of the source voltage. The active trigger signal causes a brief trigger pulse to be applied to gate electrodes of the thyristors. The varying frequency of the clock signal alters the relative times at which the thyristors are triggered to vary the amount of voltage applied to the motor. Different frequency variation functions can be stored in a memory for the starting and stopping modes.