Abstract: The invention provides improved digital data processing systems with distributed object management for use, e.g., in process control. These systems are of the type having servers and, more particularly, object request brokers (ORB's) that route requests generated by one or more clients to implementation objects maintained by a server application. Routing is based on a binding table (or other such store) that identifies dispatching procedures, or “skeletons,” that invoke requested services on implementation objects specified in the requests. Such systems may be CORBA-compatible, though the improvements provided by o the invention are applicable to distributed object management systems having other architectures, as well. The improvements are characterized by the utilization of a single entry in the binding table (or other such store) to route requests to a plurality of different implementation objects, e.g., representing process control blocks and parameters, maintained by the server.

Abstract: A method for manufacturing a Personal Computer Memory Common Interface Architecture (“PCMCIA”) printed circuit board (“PCB”) includes providing a PCB having a PCMCIA area and an auxiliary area. The PCMCIA area has multiple locations adapted to receive electronic components. The auxiliary area has multiple test points disposed thereon. The method also includes populating the PCMCIA area with electronic components. Testing of the PCMCIA area is next performed by electrically contacting at least some of the multiple test points within said auxiliary area. If the testing produces unsatisfactory results, diagnostics and repair are performed. After the testing produces satisfactory results, the auxiliary area is separated from the PCMCIA area to produce a populated, tested, PCMCIA PCB.

Abstract: An I/O device in the form of an internal dongle includes a body having connective structure being arranged to removably attach the body to a housing of an electronic device. The dongle also includes a circuit assembly that has an exterior connector on the body for electrically connecting to a second electronic device, a dongle circuit being electrically coupled to the external connector through the body, an electronic cable having a first end electrically coupled to the dongle circuit, and a second end being structured and arranged to connect to an electronic component of the first mentioned electronic device within the housing.

Abstract: A barrel lock padlock is provided which can be used to engage the hasp-and-staple fitted to an enclosure such as a gas or electricity meter box. The housing of the barrel lock has a slot into which the staple can be passed to align with the bore in the housing in which the plunger of the barrel lock is movable, so that when the plunger is moved to the locking position by its spring it passes through the staple to lock the box. A key is passed through a key hole in a cap of the lock to engage the plunger and retract it, allowing the padlock to be removed from the staple.

Abstract: A binary voting solenoid arrangement 10 is provided which operates in a “2 out of 3” manner to provide relatively high safety, low spurious tripping and a relatively low installation cost, while also enabling on-line testing of each solenoid individually without process interruption. Solenoid arrangements 10, 10′ and 10″ are preferably used in a three-way configuration, while solenoid 10′″ may be used in a two-way configuration.

Abstract: A field controller for use in a distributed control system including an area controller and at least one field controller. The field controller manages at least one controlled device in an industrial process operation. The field controller comprises a processor module segment through which it can control a selected number of devices, and it may also include one or more expansion module segments to enable it to control a larger number of controlled devices. The processor module segment includes a processor module and at least one local interface module for interfacing to a controlled device, and the expansion module segment includes interface modules for interfacing to other controlled devices. In the processor module segment, the processor module and said local interface module are interconnected by a bus segment, which is also connected to an upstream off-module connector.

Abstract: A field controller for use in a distributed control system including an area controller and at least one field controller. The field controller manages at least one controlled device in an industrial process operation. The field controller comprises a processor module segment through which it can control a selected number of devices, and it may also include one or more expansion module segments to enable it to control a larger number of controlled devices. The processor module segment includes a processor module and at least one local interface module for interfacing to a controlled device, and the expansion module segment includes interface modules for interfacing to other controlled devices. In the processor module segment, the processor module and said local interface module are interconnected by a bus segment, which is also connected to an upstream off-module connector.

Abstract: A pulse width modulation (“PWM”) generation circuit is described. The circuit includes a main PWM generator, a trimming signal generator, and a summer. The main PWM signal generator generates a main PWM output which is modified by the summer in accordance with a trimming signal produced by the trimming signal generator. In particular, the main PWM signal may be lengthened, shortened, or preserved by the summer circuit. Accordingly, the main PWM signal is trimmable, without direct modification thereof by using the trimming signal generator.

Abstract: Equipment storage apparatus, such as equipment racks and cabinets, according to the invention have a vertical load bearing member with a stepped cross-section. Thus, for example, a load bearing member of a frame according to one aspect of the invention can have two faces on its front: one with a frontward directed normal for accommodating equipment mounts, and one with a frontward directed normal for accommodating front door mounts. A pair of such load bearing members can be provided, along with one or more horizontal cross-pieces or other such structural elements, to form a frame defining a generally rectangular central region in which mounted equipment is disposed.

Abstract: An angular position sensor is couplable to an actuator for angular positional sensing of a shaft thereof. The sensor includes a base for mounting to the actuator. A diametrically magnetized permanent magnet ring is coupled to, and axially aligned with, the shaft. Further, a magnetic material cylindrical sleeve is coupled to the said base and disposed circumferentially around the magnet ring such that the sleeve is separated from said magnet ring by an air gap. A pair of diametrically opposing cylindrical segments are coupled to the sleeve by a circular support member and extend through the magnet ring. The cylindrical segments having a slot between them in which a hall effect transducer is disposed. The transducer senses the magnetic field flux of the magnet ring in the slot and thereby produces a signal indicative of the shaft's angular position.

Abstract: An article adapted to pass a cable through a housing includes a substantially solid body, including front and rear ends. A side surface of the body provides a groove extending into the body from the front to the rear end. The groove is sized to carry a selected size electric cable. The body also includes connective structure adapted to removably connect the body to the housing. The article also includes a sheet of nonconductive material extending across the groove at the front end of the body. The sheet provides a circular opening sized to allow the cable to pass therethrough. The sheet also has a slit extending from the side surface to the circular opening. The sheet is fabricated of a resilient material and is structured to allow the cable to be inserted through the slit and into the circular opening such that the cable extends along the groove and extends into the housing from the rear end of the body when the body is connected to the housing.

Abstract: A computer is connected to redundant network switches by primary and secondary connections, respectively. Test messages are sent across each connection to the attached switches. A break in a connection, or a faulty connection, is detected upon a failed response to one of the test messages. In response to this failure, traffic is routed across the remaining good connection. To facilitate fast protocol rerouting, a test message is sent across the now active connection bound for the switch connected to the failed connection. This message therefor traverses both switches causing each to learn the new routing. Rerouting is therefor accomplished quickly.

Abstract: A solid state transducer is provided for a Coriolis flow meter having a flow tube adapted to vibrate at a predetermined resonance frequency to determine mass flow rate of a fluid passing therethrough. The driver includes a strain element, such as an elongated piezoelectric or magnetostrictive element fastened axially along the wall of the tube. The strain element is adapted to oscillate in the axial direction along with the tube wall to generate and/or sense vibration of the tube in response to. The transducer may be utilized as a driver or alternatively, as a sensor wherein the transducer is oscillated along with oscillation of tube wall in the axial direction to generate an output signal responsive thereto.

Abstract: A current source circuit includes a variable impedance circuit coupling the returns of dual-floating power sources, and is configured to limit maximum current output in the event of fault and facilitate detection thereof. The first power source powers the current loop using its source, with the current loop returning through the second power source's return. Control circuitry detects an increase in current beyond the predetermined maximum and appropriately increases the impedance between the first and second power sources returns to limit current provided to the current output to the predetermined maximum. This amount of current is detected by, for example, analog to digital conversion and the fault can thereby be appropriately signaled.

Abstract: A field controller for use in a distributed control system including an area controller and at least one field controller. The field controller manages at least one controlled device in an industrial process operation. The field controller comprises a processor module segment through which it can control a selected number of devices, and it may also include one or more expansion module segments to enable it to control a larger number of controlled devices. The processor module segment includes a processor module and at least one local interface module for interfacing to a controlled device, and the expansion module segment includes interface modules for interfacing to other controlled devices. In the processor module segment, the processor module and said local interface module are interconnected by a bus segment, which is also connected to an upstream off-module connector.

Abstract: A series resonant circuit converts a DC input to an AC output. The circuit includes first and second series circuits connected across the DC input, but in opposite polarities. Each series circuit includes a switch, a transformer primary and a capacitor. Also within each series circuit, a diode is connected across the combination of the switch and transformer primary to provide limiting. The transformer primaries are connected together so that the switches are effectively in series. Singular and multiple transformer cores may be used in connection with singular and multiple secondaries to provide the AC output.

Abstract: A circuit used to convert a DC input to an AC output includes a pair of series circuits. Each of the series circuits is in parallel with the DC input and includes a switch and a transformer primary. A capacitor couples the two series circuits, and is attached to each series circuit at a node between the respective transformer primary and switch. A secondary on the transformer provides the AC output. Optionally, multiple transformers may be utilized. Similar topologies may be used for rectification instead of inversion.

Abstract: A field mountable controller boots by transmitting a seed letterbug to a server. The server responds with an initial operating system and program. The program reads configuration information about the controller and transmits it back to the server which responds with a particular letterbug for the controller. The controller then transmits the letterbug to a boot image server which returns a corresponding operating system image to the controller. The controller then boots using the operating system.

Abstract: A solenoid actuated valve has a magnetic armature slidably received in a closed guide member secured to the valve body by a spin welded ring. The armature guide has external peripheral teeth which interengage corresponding internal teeth on the solenoid coil assembly to permit any desired rotational orientation of the coil when assembled onto the guide. The coil assembly is secured in the desired rotational position by interengagement of the teeth and is secured axially by snap tabs formed on the end of the guide.

Abstract: In a process control system, a user selects a displayed object. The user then asks to be shown documents related to the selected object. A list of related documents is automatically displayed to the user who may then select a document for display. The association of documents with displayed process control objects is facilitated by a document librarian. Within the document librarian, a user drags documents from within a document hierarchy over to hierarchically designated objects within the process control system, and drops them thereon. Links between the documents and the process control objects are thereby established.