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US 4,974,179 AGranted
Method and apparatus for preventing race conditions in a control system
AssigneeHoneywell Inc.
InventorsPaul B. Patton, Kenneth B. Kidder
Life of this patent
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AssigneeHoneywell Inc.
InventorsPaul B. Patton, Kenneth B. Kidder
Estimating the term…
The present invention is a method and apparatus for preventing a decision made by a controller from being made based on incomplete information where the controller periodically runs a decision making routine. The controller makes decisions based on a plurality of AC input signals being present or absent. The presence or absence of the AC input signals is read by the controller during a read cycle performed during periodic half cycles of the AC system signal. The AC system signal and the AC input signals are substantially phase-synchronizes. Before the controller runs the decision making routine, the controller determines whether the presence or absence of the AC input signals has changed since the previous decision making routine. Where the presence or absence of the AC input signals has changed since the previous decision making routine, the decision making routine is delayed for a predetermined number of half cycles of the AC system signal.
A method for preventing decisions made by a controller from being based on incomplete information, the controller periodically running a decision making routine making decisions based on a plurality of AC input signals representing a plurality of system parameters the AC input signals having a first status when they are above a minimum threshold level, and a second status when they are below a minimum threshold level, where a change in a single system parameter can cause a change in the status of a plurality of AC input signals, the status of the AC input signals being read by the controller during a read cycle performed during periodic half cycles of an AC system signal, and where the AC system signal and the AC input signals are substantially phase-synchronous, the method comprising the steps of:
An apparatus for preventing decisions made by a controller from being based on incomplete information, the controller suitable for controlling a control system running a decision making routine for making decisions based on a plurality of AC input signals representing a plurality of system parameters, the AC input signals having a first status when they are above a minimum threshold level, and a second status when they are below a minimum threshold level, where a change in a single system parameter can cause a change in the status of a plurality of AC input signals, where the status of the AC input signals is read by the controller during read cycles performed during periodic half cycles of an AC system signal and where the AC system signal, and the AC input signals are substantially phase-synchronous, the apparatus comprising:
A method for controlling a heating system having a plurality of AC input signals where presence or absence of the AC input signals above a minimum threshold level represents a status of sensed parameters in the heating system, where a change in the status of a single sensed parameter can cause a change in the presence or absence of a plurality of the AC input signals above the minimum threshold level and where the AC input signals are substantially phase-synchronous with an AC system signal, the method comprising the steps of:
Dependencies are inferred from the claim text.