Abstract: Embodiments of a phase difference estimator and method are generally described herein. The phase difference estimator includes a delay element to delay a reference clock signal that includes an alternating symbol waveform by one of a plurality of delay values. The phase difference estimator further includes a sampler to sample a monitored clock signal provided by a second device responsive to edges of the delayed reference clock signal to generate a sampled signal output. The phase difference estimator further includes a correlation element to correlate the sampled signal output of the sampler with a step function to generate a correlation value for each delay value, and a controller to instruct the delay element to delay the reference clock signal by one of the delay values and provide a phase difference estimate output indicative of a phase difference between the reference and monitored clock signals based on the correlation value.

Abstract: Embodiments of a phase difference estimator and method are generally described herein. The phase difference estimator includes a delay element to delay a reference clock signal that includes an alternating symbol waveform by one of a plurality of delay values. The phase difference estimator further includes a sampler to sample a monitored clock signal provided by a second device responsive to edges of the delayed reference clock signal to generate a sampled signal output. The phase difference estimator further includes a correlation element to correlate the sampled signal output of the sampler with a step function to generate a correlation value for each delay value, and a controller to instruct the delay element to delay the reference clock signal by one of the delay values and provide a phase difference estimate output indicative of a phase difference between the reference and monitored clock signals based on the correlation value.

Abstract: Embodiments of a high-resolution link-path delay estimator and method are generally described herein. The high-resolution link-path delay estimator may estimate a signal-path delay of a signal path between a master and remote device. The high-resolution link-path delay estimator may phase-shift a transmit signal of alternating symbols by phase-shift values and may sample a loopback signal. A noise-reduced version of the sampled signal output may be correlated with a step function to generate a correlation value for each of the phase-shift values. One of the phase-shift values may be selected to generate a fine-delay estimate which may be added to a coarse delay estimate to determine the signal-path delay. The coarse delay estimate may be an estimate of the signal-path delay to a nearest symbol period of the transmit signal and the fine-delay estimate may be an estimate to within a fraction of the symbol period.

Abstract: In a partially interconnected topological network having at least six topological nodes, a topological node being a single physical node or a group of interconnected physical nodes or part of a physical node or a group of interconnected physical nodes and parts of physical nodes, each topological node having at least three point-to-point topological links connecting it to some, but not all, of the plurality of topological nodes, there is at least one choice of routing between any two topological nodes, where the choice of routing is either two point-to-point topological links connected in series at another of the topological nodes or a direct point-to-point topological link between the two topological nodes.

Abstract: In a partially interconnected topological network having at least six Topological Nodes, a Topological Node being a single Physical Node or a group of interconnected Physical Nodes or part of a Physical Node or a group of interconnected Physical Nodes and parts of Physical Nodes, each Topological Node having at least three point-to-point Topological Links connecting it to some but not all of the plurality of Topological Nodes and there being at least one Choice of routing between any two Topological Nodes, where a Choice of routing is either two point-to-point Topological Links connected in series at another of the Topological Nodes or a direct point-to-point Topological Link between the two Topological Nodes.

Abstract: In a fractional distillation tower which is divided into a plurality of sections by total drawoff trays, and wherein at least one fraction is withdrawn from each section. The cut point temperature between fractions is determined based on the partial pressure and temperature of the vapor in the upper portion of a section. The thus determined cut point temperature may be compared to a set point with the results of the comparison being utilized to maintain the actual cut point temperature between fractions substantially equal to the desired cut point temperature.

Abstract: A computer system for a zone fired furnace generates a plurality of temperature set point signals for a plurality of furnace zones. The set point signals are derived from a master controller acting on the measured temperature of fluid that is heated in the plurality of furnace zones and then combined to form a heated stream. The master signal, which is a velocity type signal, is provided to a plurality of zone control stations corresponding to the plurality of furnace zones. Each zone control station integrates the master signal, and then biases the master signal for use as a zone temperature set point. The zone control station can be used to bias the individual coils so as to balance the temperature of the coils with respect to each other, or to intentionally unbalance one or more coils, as desired, so as to improve furnace operations.

Abstract: A supervisory computer automatically equalizes the temperature of effluent streams of a multipass heating system to maximize heat transfer, without substantially disturbing a desired total flow through the heating system. Temperature control is achieved by manipulating the division of a feed stream among the multiple passes. In addition, if the flow in one or more passes cannot be manipulated, the control scheme automatically equalizes the temperatures of the remaining passes. This is accomplished by calculating a flow rate for adjusting the flow through the number of passes under supervisory control to a value, which in addition with any uncontrolled flow, will provide the desired total flow through the heating system. This adjusted flow rate is used as an approximate set point for the flow rate in each controlled pass. The adjusted flow rate signal is modified for control of each individual pass by applyng a bias through a conventional controller acting on a weighted average temperature signal.

Abstract: A computer control system for automatically optimizing the temperature of the feed supplied to a distillation column from a fuel fired preheat furnace, wherein the furnace temperature is manipulated in response to a measured ratio of distillate flow (D) from the tower to fuel flow (F) to the furnace. The D/F ratio is maximized by periodically comparing the present value of D/F to the previous value and incrementally increasing the furnace temperature as long as the D/F ratio increases. When no change is detected or the D/F ratio starts to decrease the furnace temperature is incrementally decreased until the D/F ratio again increases and reverses the control action once more.

Abstract: In a fractional distillation process in which both a heating fluid and a waste heat stream are utilized to supply heat to the fractional distillation process, the heat input to the fractional distillation process is controlled by scaling the output of the heat controller so that such output is representative of the percentage of the total heat available which should be supplied to the fractional distillation column to maintain a desired heat input to the fractional distillation column. The set point for the flow of both the heating fluid and the waste heat stream are then derived based on the output of the heat controller which allows control of heat input to the fractional distillation process and also provides a situation where the heat controller output may be linear which makes tuning the heat controller easier and improves stability of the heat controller.

Abstract: In a fractional distillation process in which the designation of the primary product stream changes, the desired composition of the primary product stream and a secondary product stream are maintained without losing automatic control of the process for an extended period of time while the controllers controlling the process are retuned for the new operating conditions. Two sets of tuning constants are available to each controller and these tuning constants are automatically switched as required by the designation of the primary product stream.

Abstract: A control system for distillation column with a sidedraw line is provided wherein a prediction on the influence by changes in the feed stream with respect to the sidedraw composition is made.

Abstract: In a fractional distillation process in which the designation of the primary product stream changes, the desired composition of the primary product stream and a secondary product stream are maintained without loosing automatic control of the process for an extended period of time while the controllers controlling the process are retuned for the new operating conditions. Two sets of tuning constants are available to each controller and these tuning constants are automatically switched as required by the designation of the primary product stream.