Abstract: A method and apparatus for determining speed of a stepper motor. In one embodiment of the method, a first terminal of a first coil of the stepper motor is coupled to an input of a multibit digital-to-analog (A/D) convertor. The stepper motor's a rotor is rotated about an axis while the first terminal is coupled to the multibit A/D convertor. An analog signal is induced at the first terminal generating while the rotor is rotating about the axis. The multibit A/D convertor receives the analog signal induced at the first terminal. The multibit A/D convertor generates a plurality of multibit digital signals in response to receiving the analog signal. The multibit digital signals can be processed to determine the rotational speed at which the rotor was rotating when the A/D convertor generated the plurality of multibit digital signals.

Abstract: A method and apparatus for determining speed of a stepper motor. In one embodiment of the method, a first terminal of a first coil of the stepper motor is coupled to an input of a multibit digital-to-analog (A/D) convertor. The stepper motor's a rotor is rotated about an axis while the first terminal is coupled to the multibit A/D convertor. An analog signal is induced at the first terminal generating while the rotor is rotating about the axis. The multibit A/D convertor receives the analog signal induced at the first terminal. The multibit A/D convertor generates a plurality of multibit digital signals in response to receiving the analog signal. The multibit digital signals can be processed to determine the rotational speed at which the rotor was rotating when the A/D convertor generated the plurality of multibit digital signals.

Abstract: A process control interface system having a network of distributed triply redundant input/output field computer units. The system includes a plurality of self-contained remotely located triply redundant field computer units connected to decision making redundant process control computers through a bi-directional communication network having at least two concurrently active communication channels. Each of the field computer units include a set of at least redundant field computers for arbitrating both input and output signals. The input arbitration method enables a plurality of selectable default input conditions, such as select HIGH and select LOW, in the event that a majority agreement cannot be reached among valid input signals. The output arbitration method includes a plurality of selectable default output conditions, such as fail SAFE and fail LAST. Each of the default input and output conditions may be rapidly adjusted through software selection.

Abstract: A process control interface system having a network of distributed triply redundant input/output field computer units. The system includes a plurality of self-contained remotely located triply redundant field computer units connected to decision making redundant process control computers through a bi-directional communication network having at least two concurrently active communication channels. Each of the field computer units include a set of at least redundant field computers for arbitrating both input and output signals. The input arbitration method enables a plurality of selectable default input conditions, such as select HIGH and select LOW, in the event that a majority agreement cannot be reached among valid input signals. The output arbitration method includes a plurality of selectable default output conditions, such as fail SAFE and fail LAST. Each of the default input and output conditions may be rapidly adjusted through software selection.

Abstract: A process control interface system having a network of distributed triply redundant input/output field computer units. The system includes a plurality of self-contained remotely located triply redundant field computer units connected to decision making redundant process control computers through a bi-directional communication network having at least two concurrently active communication channels. Each of the field computer units include a set of at least redundant field computers for arbitrating both input and output signals. The input arbitration method enables a plurality of selectable default input conditions, such as select HIGH and select LOW, in the event that a majority agreement cannot be reached among valid input signals. The output arbitration method includes a plurality of selectable default output conditions, such as fail SAFE and fail LAST. Each of the default input and output conditions may be rapidly adjusted through software selection.

Abstract: A process control interface system having a network of distributed triply redundant input/output field computer units. The system includes a plurality of self-contained remotely located triply redundant field computer units connected to decision making redundant process control computers through a bi-directional communication network having at least two concurrently active communication channels. Each of the field computer units include a set of at least redundant field computers for arbitrating both input and output signals. The input arbitration method enables a plurality of selectable default input conditions, such as select HIGH and select LOW, in the event that a majority agreement cannot be reached among valid input signals. The output arbitration method includes a plurality of selectable default output conditions, such as fail SAFE and fail LAST. Each of the default input and output conditions may be rapidly adjusted through software selection.