Abstract: Sensor selection status monitoring and maintenance logic for generating messages relating to intermittent and “in-range” faults are described. In one embodiment, a transition count is generated indicating a number of times the selection status number changes during a flight. A time duration table is generated indicating an amount of time a selection status number is recorded in each of its possible states during the flight. The maintenance logic utilizes outputs from the monitoring logic to generate maintenance messages.

Abstract: The invention concerns an interface for a digital electronic control for a gas turbine engine. The interface allows one to gain access to random access memory in the control, wherein data of interest is stored. The data includes information about present operating conditions of the engine, such as component speeds and temperatures, as well as data concerning the health of components. The data is in digital format, but is converted into analog format within the control and transmitted from the control in analog format. The analog data is used to drive a recording device, such as a strip chart recorder, thus allowing information about the engine to be transmitted to a location remote from the engine, in real time.

Abstract: A signal quantizer is disclosed which compares an input signal with a plurality of predetermined adjustable thresholds, associates with each threshold a potential output signal of predetermined adjustable magnitude, identifies the largest threshold exceeded by the input signal, and produces as an output signal a signal representative of the potential output signal associated with the threshold identified.