Abstract: The resolver drive circuit on a numerical control system includes a microprocessor system which monitors the phase and amplitude of the sinusoidal wave forms applied to the resolver. Any changes in amplitude or phase shift of the applied wave forms due to such factors as time and temperature are automatically corrected by the microprocessor system. A highly accurate resolver position feedback system is thus formed with a minimal number of temperature sensitive components and a minimal number of required manual adjustments to analog circuitry.

Abstract: A push button switch has an operator that is mounted for axial movement within a bezel towards its exit end. A contact assembly is disposed across the exit of the bezel. The contact assembly includes a pair of termination areas formed on a substrate and a shorting patch disposed on a flexible membrane, the shorting patch being separated from the termination areas by a spacer to provide a switch air gap. A second spacer is disposed on the other side of the substrate and forms an air reservoir that communicates with the switch air gap through an aperture in the substrate. When the operator is moved against the membrane to close the switch air gap, air is circulated into the air reservoir increasing the pressure therein, and returns to break the contact of the termination areas with the shorting patch when the operator is retracted.

Abstract: A protection circuit protects a motor against excessive energizing current and exposure time conditions in accordance with the inverse relationship existing between these quantities. The circuit includes a pulse generator which generates a pulse train signal having a pulse rate proportional to the magnitude of the excess current applied to the motor. The pulses of the pulse train signal are counted up in a counter to a predetermined number. When that number is reached, the circuit operates to disconnect the motor. The greater the excess motor current, the higher the pulse rate of the pulse train signal, and the shorter the counting time required to obtain the predetermined number. The inverse relationship between excess current magnitude and exposure time is thus obtained. The circuit indicates when excess current is being applied to the motor and retains that indication after disconnection.

Abstract: A CRT terminal includes a main unit which houses circuitry and the CRT display. An application module which includes a keyboard plugs into the front of the main unit and electrically connects to its circuitry. A flexible membrane keyboard is employed which includes a keyboard overlay that is easily changed to provide keyboard symbols appropriate to a wide variety of different applications. Resilient bumpers extend completely around the main unit to facilitate its use in industrial applications where physical abuse is common.

Abstract: An assembly for connecting a tubular conduit to an apertured wall of a non-metallic enclosure including a tubular insert seated in the aperture and a threaded, rotatable, hollow hub member arranged to be received by an externally projecting portion of the tubular insert. The closed end of the hub member adjacent the enclosure rests against a compressible resilient ring for sealing engagement and being further adopted for rotatable engagement with respect to the enclosure by means of an interposed washer made of a material having relatively low coefficient of friction with respect to the hub member. The components of the assembly are held together by means of a laterally extending lip formed at the distal end of the insert after assembly of the cooperating elements to the enclosure.

Abstract: A secondary, protective triac is connected in series with a main load-control triac in an a-c output circuit for a programmable controller. The two triacs are coupled to a pair of digital inputs and when the main triac is conducting the secondary triac is not conducting--unless the main triac stays "on" after an "off" signal is received, signifying a shorted main triac. If that occurs, a triac-failure fuse is blown and the secondary triac switches to conduct current and complete a virtually short circuit through a main power fuse. The blowing of the triac-failure fuse illuminates a neon bulb to give an indication of a main triac failure, and the blowing of the main power fuse illuminates a corresponding neon bulb to indicate a failure on the module and its disconnection from the load.

Abstract: An armature for electric motors having a magnetic core of stacked laminations mounted on a shaft with a plurality of electrically conductive rotor bars disposed in the magnetic core, and also having a number of arch shaped permanent magnets disposed in the core that are circularly spaced from one another and arranged concentrically with the shaft. Each permanent magnet has a pole of one magnetic polarity on its radially outer face and a pole of opposite polarity on its radially inner face, and is surrounded by magnetic core material at its circumferential ends and radially inner side to form flux return paths, whereby there are two magnetic armature poles for each permanent magnet.

Abstract: An industrial communications network includes microprocessor-based interface circuits which each connect a controller such as a programmable controller to a high speed serial data link. Each interface circuit connects to the data link and its associated controller, and each is operable to receive messages on the data link directed to its associated controller. In addition, each interface circuit can assume mastership of the communications network when the existing master generates a poll command indicating it is ready to relinquish mastership. As a result, the communications network will continue to function even though one or more controller or their associated interface circuits become inoperable.

Abstract: An adjustment mechanism for a pneumatic timing device, that operates relay contacts with a time delay, in which a needle valve is aligned longitudinally with a bellows and the needle valve is operated by a rotatable adjustment knob that operates a visual indicator through a reduction gearing.

Abstract: A programmable controller includes a microprocessor which operates in response to machine instructions stored in a read-only memory. A control program comprised of programmable controller-type instructions is stored in a random access memory. These are executed by translating their operation codes into the starting addresses of corresponding sets of machine instructions. In addition, one or more "universal instructions" may be contained in the control program, and when these are read from the random-access memory, they are translated to enable the microprocessor to execute a user defined set of microprocessor machine instructions. These user defined machine instructions may be stored in a read-only memory or they may be stored in the random access memory with the control program. The programmable controller may thus effectively be programmed in two languages, a programmable controller language and a microprocessor machine language.

Abstract: A programmable controller has a high density I/O module for interfacing eight analog input devices to a main processor module. The high density I/O module has a microcomputer for reading, storing and updating eight words of input data. The microcomputer also communicates with the main processor of the main processor module to transfer the eight words of input status data to a main memory. The main processor is programmed to communicate with the microcomputer in two alternate modes. In one mode the main processor is directed by an applications control program to individually couple words of the status data; in the other mode the main processor is directed by firmware instructions to alter the input/output scan and couple a block of input data.

Abstract: A programmable controller interfaces a numerical control system to sensing and operating devices that control the auxiliary functions on a machine tool. In the controller a microprocessor is coupled to a random-access memory (RAM) and an electrically alterable read-only memory (EAROM) through an address bus and a data bus. The RAM stores a user control program and an I/O image table that depicts the status of the sensing and operating devices on the machine tool. Under program control the microprocessor verifies the contents of the RAM and copies the verified contents into the EAROM. If the contents of the RAM are altered or lost, the master copy of data stored in the EAROM is reloaded into the RAM.

Abstract: A summing watt-hour transducer is connected to a three-phase power line to monitor the energy being supplied to one load, and is connected to an ordinary watt-hour transducer that monitors energy supplied to a second load. A summing integrator circuit sums and integrates signals derived from the power line and the ordinary watt-hour transducer to obtain a voltage proportional to a unit of total energy demand. The summing operation is triggered by a signal from a control circuit that is responsive to contact closure pulses from the ordinary watt-hour transducer. Output signals from the summing integrator circuit are converted to contact closures for input of energy demand signals to an energy demand/schedule controller.

Abstract: A small, low-cost programmable controller is programmed with both bit-oriented and word oriented program instructions that are stored in a main memory. A microprocessor couples each program instruction to a respective interpreter routine of machine instructions stored in an interpreter memory. Bit-oriented program instructions with a common operation code but different bit-pointer codes are coupled to their own respective interpreter routines. The program instructions have operation codes and bit pointer codes that are assigned by a program panel, and are then translated by a translator PROM as they are coupled to an interpreter routine. Operand addresses are read through the translator PROM unchanged. Error-locating circuitry assists in detecting faulty chips in the main memory as the control program is executed. The hardware required to execute the control program is minimized, while the translator PROM allows the processor unit to be used with prior program panels.

Abstract: A memory circuit receives memory modules which may vary in their size and their type. The memory circuit includes a decoder circuit which receives size feedback signals from each memory module which enables it to automatically assign each module the address space it requires. If the size of a memory module is changed, the decoder circuit reassigns the address space to accommodate the new module. Type feedback signals generated by each memory module enable the memory circuit to apply the proper control signals and enable the proper supporting circuitry when the memory module is addressed.

Abstract: An input circuit for a digital control system includes a rectifier circuit, a current limiting circuit and a set of zener diodes which can be selectively employed to receive a wide variety of signals from industrial sensing devices. The signal is generated to an output drive circuit by an optocoupler which provides electrical isolation. The output drive circuit generates a logic level signal which is compatible with the digital electronic control system. The input circuit is particularly well suited for fabrication as an integrated circuit.

Abstract: A programmable controller includes a processor formed around a pair of four-bit bipolar microprocessors. A control program formed by selected macroinstructions is stored in a random access memory and it is executed by sequentially mapping each macroinstruction operation code into a corresponding microroutine which is stored in a read-only memory. Some macroinstructions include operand addresses of a line in an I/O image and data table portion of the random access memory, and one macroinstruction (ADX) expands this operand address to enable the I/O image and data table to be expanded in size. A timer macroinstruction is executed in part by reading the state of a counter which is driven by a real time clock, and arithmetic functions are performed with the use of a decimal adjust accumulator.

Abstract: Associated with each processor in a multiprocessor numerical control system is a watchdog timer circuit which is periodically reset by its processor under normal operating conditions. If a malfunction should occur in one of the processors, its watchdog timer is not reset and it times out. A fault monitor line connects to each watchdog timer circuit and an emergency stop circuit, and when a malfunction occurs in any one of the processors, this condition is indicated to all the processors and to the emergency stop circuit.

Abstract: A pneumatic timer for a timing relay is regulated by the axial movement of a valve needle through a chamber formed in the body of the timer. The valve needle forms a tapered valve stem along its longitudinal axis and the valve stem is eccentrically disposed in a passageway leading from the valve chamber to provide a crescent-shaped bleed area between the valve chamber and the interior of an expandable bellows. Springs are disposed in the valve chamber to bias the needle to its eccentric position, where the valve stem contacts a portion of a valve seat formed around the passageway. The size of the bleed area between the valve stem and the noncontacting portion of the valve seat changes as the valve needle is moved along its axis, but the shape of the bleed area remains substantially the same, so that the valve can more easily be set to provide the desired time delay.

Abstract: A rack adapter for a programmable controller is included in each of four remotely located I/O interface racks that are connected in series to a central processor. The rack adapter includes a rack interface processor under program control which converts serial data received from the central processor to parallel data that is written into I/O modules in its rack. The rack interface processor also converts parallel data from I/O modules to serial data, which is sent back to the central processor through a select data out circuit in proper sequence with data from the other racks. The rack interface processor initiates the decontrol of machines connected to the four racks if a major transmission fault occurs, but the rack interface processor is tolerant to transmission errors caused by electrical noise.