Abstract: A system comprising a local site served by at least one remote site in digital logic communication therewith, the system further comprising mode selection logic including a hierarchy that prioritizes modes available at the local site. The hierarchical priority of a particular mode that may be selected at the local site or at any one of the remote sites determines the mode in which the local site will operate, further depending on the current mode selection state at other remote or local sites. A presently preferred embodiment of the invention is a valve actuator having three-way local mode selection capability (local/remote/off), where such mode control is additionally served by at least one remote site connected via a serial link to the local site of the actuator. In this exemplary embodiment, a hierarchy prioritizes these modes in the following order of high priority to low priority: (1) off; (2) local; (3) remote.

Abstract: Condensation draining system and method for valve stem protectors comprising an actuator and a stem protector assembly structured in combination to provide a drain and an opening for draining condensation from inside the assembly to outside the combination.

Abstract: An absolute position detector that interprets, rather than avoids, abnormal sensory states. Different combinations of sensors in an array are activated as a marker travels along a path. The current activation/deactivation state of the array is converted into a digital signal that is reliably indicative of the current absolute position of the marker along the path. In a preferred embodiment, a dynamic magnetic field is provided whose current condition represents the current absolute position of a moving marker. As the marker moves, the condition of the field changes to activate different groups of Hall Effect devices in an array. The activated groups may comprise one or more Hall Effect devices in the array, depending on the condition of the field as created by the position of the marker. The current activation/deactivation state of the array is then converted, advantageously via truth table logic, into a digital signal representative of the current position of the marker.

Abstract: An inventive encoding system that expects, accepts and interprets both normal and abnormal states of a sensor array, and that preferably further recognizes a zero state as a malfunction. The system is “absolute,” in that it allows detection of the best fit detectable position of a movable object with an accuracy equal to the resolution which is equal to one-half the physical displacement of sensors or sources in an array. Such absolute references may be used to define a position detector which properly detects the position of an object after power is applied, even though the object may have moved further after power is removed. As a result, the inventive encoder does not require a battery back-up to detect position accurately after a power failure. This functionality is highly advantageous when detecting shaft position of a multi-turn shaft. The inventive encoding system is also scalable so that there are few limitations in deployment.

Abstract: A system comprising a local site served by at least one remote site in digital logic communication therewith, the system further comprising mode selection logic including a hierarchy that prioritizes modes available at the local site. The hierarchical priority of a particular mode that may be selected at the local site or at any one of the remote sites determines the mode in which the local site will operate, further depending on the current mode selection state at other remote or local sites. A presently preferred embodiment of the invention is a valve actuator having three-way local mode selection capability (local/remote/off), where such mode control is additionally served by at least one remote site connected via a serial link to the local site of the actuator. In this exemplary embodiment, a hierarchy prioritizes these modes in the following order of high priority to low priority: (1) off; (2) local; (3) remote.

Abstract: An absolute position detector that interprets, rather than avoids, abnormal sensory states. Different combinations of sensors in an array are activated as a marker travels along a path. The current activation/deactivation state of the array is converted into a digital signal that is reliably indicative of the current absolute position of the marker along the path. In a preferred embodiment, a dynamic magnetic field is provided whose current condition represents the current absolute position of a moving marker. As the marker moves, the condition of the field changes to activate different groups of Hall Effect devices in an array. The activated groups may comprise one or more Hall Effect devices in the array, depending on the condition of the field as created by the position of the marker. The current activation/deactivation state of the array is then converted, advantageously via truth table logic, into a digital signal representative of the current position of the marker.

Abstract: An absolute position detector that interprets, rather than avoids, abnormal sensory states. Different combinations of sensors in an array are activated as a marker travels along a path. The current activation/deactivation state of the array is converted into a digital signal that is reliably indicative of the current absolute position of the marker along the path. In a preferred embodiment, a dynamic magnetic field is provided whose current condition represents the current absolute position of a moving marker. As the marker moves, the condition of the field changes to activate different groups of Hall Effect devices in an array. The activated groups may comprise one or more Hall Effect devices in the array, depending on the condition of the field as created by the position of the marker. The current activation/deactivation state of the array is then converted, advantageously via truth table logic, into a digital signal representative of the current position of the marker.

Abstract: A drive shifting apparatus for a valve control and the like is provided with a source of power for motor operation, a separate source of power for hand operation and a shifting means shiftable between the hand power and motor power sources. The shifting means may be a spring loaded clutch normally connecting the motor power source with the valve control, a latch means to hold the clutch in the hand power position against the spring pressure and a cam on the motor automatically releasing the latch when the motor is energized.