Abstract: A terminator reduces reflections on power lines connecting an inverter to an AC motor by providing a differential-mode reflection damping element and at least one common-mode reflection damping element, the latter including a series capacitance to substantially reduce power dissipation in the resistance of the damping elements.

Abstract: A safety switch that includes a housing, a first switch, and a second switch. The switch has a two part rod that is axially moveable within the housing. The parts of the rod are co-operable with respect to one another and independently operable to activate one of the first and second switches. A biasing element is arranged to bias the rod parts into contact with a cam arrangement and arranged to bias the rod parts out of engagement with one of the respective switches. The cam arrangement is configured such that rotation of the cam arrangement will move the rod parts thereby activating the switches to allow the safety switch to conduct electricity.

Abstract: An industrial control monitoring system provides visualization of historical data acquired from an industrial process in a manner that mimic real-time visualization of real-time data acquired from the industrial process. The monitoring system provides an operator interface that allows the operator to direct playback interactively, such as rewinding and forwarding of the playback.

Abstract: Fault-tolerant Ethernet is provided through the use of special interfaces providing duplicate ports that may be alternatively enabled with the same network address. A switching between the ports, corrects for single faults in a two-way redundant system without time-consuming reconfiguration of other end devices or the need for complex middleware in the end devices.

Abstract: A distributed control system and methods of operating such a control system are disclosed. In one embodiment, the distributed control system is operated in a manner in which interrupts are at least temporarily inhibited from being processed to avoid excessive delays in the processing of non-interrupt tasks. In another embodiment, the distributed control system is operated in a manner in which tasks are queued based upon relative timing constraints that they have been assigned. In a further embodiment, application programs that are executed on the distributed control system are operated in accordance with high-level and/or low-level requirements allocated to resources of the distributed control system.

Abstract: A control system for controlling and synchronizing a plurality of medium-voltage vacuum contactors comprises a two-level network structure. A dedicated network includes a plurality of servant control units operably coupled to the vacuum contactors and configured to ascertain a plurality of different data and conditions thereof. In addition, the dedicated network includes a master control unit in serial communication with the servant control units and configured to send and receive communications therewith. The master control unit is operably coupled to a control network including a plurality of various control devices. The master control unit is configured to send predetermined data received from the servant control units to the control network. The two-level network structure enables relatively jitter free communication on the dedicated network while not overwhelming the control network with unnecessary data.

Abstract: A current-loop output circuit for an industrial controller provides for low power dissipation and reduced part count by driving current loads of different resistances directly from a switched voltage source. Proper filtering and design of a feedback loop allows the necessary transient response times to be obtained.

Abstract: A safety switch plunger includes a moveable conductor which extends transversely through the plunger and protrudes from opposite sides of the plunger. The plunger is provided with a structure that is positionally fixed on the plunger. The structure is positioned such that it is arranged to come into physical contact with and affect the movement of the moveable conductor when the moveable conductor and plunger are moved relative to one another thereby providing a fail-to-safe safety switch.

Abstract: A safety switch assembly having a handle pivotably attached to a casing to allow selective operation of an electrical contact assembly. The handle is attached to the casing with a movable pivot such that excessive grip pressure renders the safety switch inoperable until the safety switch is reset. The handle is moveable responsive to grip pressures that range from no actuation to a first grip pressure. Actuation of the handle in this range controls operation of the electrical contact assembly. Gripping of the switch with a grip pressure greater than the first grip pressure moves the pivot such that the safety switch is rendered inoperable, or non-conductive, until manipulation of a reset actuator returns the pivot to a pivot position associated with the first operating zone. Such a construction provides a safety switch that can be rendered inoperable and reset to allow subsequent operation.

Abstract: This invention relates to line frequency synchronisation for use in diagnostics for alternating current electrical circuits. The invention provides a method of synchronising measurement system frequency with an alternating current line frequency comprising the steps of: adjusting the frequency of the measurement system frequency using a frequency locked loop until the measurement system frequency is within a predetermined range of said alternating current line frequency; and when the measurement system frequency is within a predetermined range of said alternating current line frequency adjusting the phase and the frequency of the measurement system frequency using a phase and frequency locked loop.

Abstract: A new industrial control system and method are disclosed allowing for communication between multiple control devices of the system and remote devices via the Internet. The system includes a web access interface that is capable of being coupled to the remote devices via the Internet, and is coupled to the control devices by way of a network. A program executed by the interface receives an Internet signal having socket API data and formatted in accordance with the TCP/IP protocol, and extracts the data from the Internet signal. Another program executed by the interface receives the data and transmits a network signal, which includes the data but is not formatted in accordance with the TCP/IP protocol, to an appropriate one of the control devices, each of which has a respective web server program. The data is processed by the server program at the appropriate control device.

Abstract: This invention relates to fault detection in electrical circuits. The invention provides a switch for a fault tolerant digital output module comprising: an output transistor pair for enabling and disabling an alternating output current; and a current limiter for clamping the output current to a predetermined maximum value.

Abstract: A contactor assembly includes a stationary contact, an arc contact, an arc arrestor, and a magnetic intensifier. The magnetic intensifier is constructed to extend in generally close proximity to one of the stationary contact and the arc contact. During communication of power through the contactor assembly, the magnetic intensifier manipulates a magnetic field associated with current passing through the contactor assembly and increases the magnitude of a magnetic force directed to the arc arrestor. Preferably, the magnetic intensifier is formed integrally with a turnback associated with one of the stationary contact or the arc contact. Such a construction simplifies the manufacture and assembly of the contactor assembly and provides efficient and repeatable arc suppression.

Abstract: A safety switch that includes a locking mechanism having a rod locking element that is located adjacent to a rod and engageable with the rod to lock the rod in position relative to a housing. The safety switch locking mechanism includes a locking member that is moveable relative to the housing in response to a difference in inertia between the locking member and the housing when a force is applied to the housing. The locking member is arranged to inhibit disengagement of the rod-locking element from the rod when the force is applied to the housing.

Abstract: A inter-network interface device usable in a highly reliable industrial control system provides an interface between a producer module transmitting redundant messages in accordance with a communication protocol and a consumer module receiving the messages in accordance with a different communication protocol. The inter-network interface device includes a first network interface receiving two messages from the producer, a microprocessor capable of converting the messages from the producer communication protocol to consumer communication protocol, and a second network interface transmitting the messages to the consumer. One of the messages is reversible altered with respect to the other message. The altered message is uninverted in the consumer module, and compared to the other message to ensure that no transmission errors have occurred.

Abstract: A method of forming a switch assembly that includes a magnetic intensifier constructed to extend in generally close proximity to one of the stationary contact and the arc contact. During communication of power through the contactor assembly, the magnetic intensifier manipulates a magnetic field associated with current passing through the switch assembly and increases the magnitude of a magnetic force directed to the arc arrestor. Preferably, the magnetic intensifier is formed integrally with a turnback associated with one of the stationary contact or the arc contact. Such a construction simplifies the manufacture and assembly of the contactor assembly and provides efficient and repeatable arc suppression.

Abstract: An industrial controller includes a processing unit and a memory. The industrial controller is operable to communicate using an optimized connection packet including I/O data from a plurality of I/O modules arranged as an unstructured data block. The processing unit is operable to operate on the I/O data within the optimized connection packet to control a process. The memory is operable to store a plurality of cast tags. Each cast tag is associated with one of the I/O modules and provides a logical reference to a subset of the unformatted data block including at least a portion of the I/O data for the associated I/O module.

Abstract: A safety switch assembly includes a body constructed to be mounted in a support structure and generally enclose the operative structure of the safety switch. The safety switch assembly includes an actuator constructed to pass through one of the support structure or the base to operatively engage the operative structure of the safety switch to control the safety switches electrical orientation to communicate or terminate communication of electrical power to a device equipped with the safety switch.

Abstract: A hybrid backplane uses multiple, parallel serial communication channels to provide flexibility and robustness in a motor drive control requiring high-speed data communication for the real-time control of motor waveforms.

Abstract: Error detection codes implemented in standard network interface circuits are enlisted in obtaining high reliability necessary for safety systems by virtual testing of the network interface circuits using background levels of network errors. The frequency of the testing matches the frequency of the network errors.