Abstract: A multiple synchronized agile pulse generator is configured as high speed digital/analog test apparatus for providing complex patterns associated with modern avionics systems. The multiple synchronized agile pulse generator includes a network of counters and random access memory (RAM) banks which allow for predetermined hopping of pulse repetition intervals, pulse widths, pulse patterns, pulse amplitudes, and combinations of the above.

Abstract: Apparatus for generating synchro/resolver stimulus signals is disclosed wherein the stimulus signals are generated in an arbitrary time sequence of synchro/resolver shaft angles under control of an external computer. Data from the computer is applied to random access memory (RAM) banks and is read out from sequential RAM address locations at a predetermined rate to two independent digital to synchro/resolver converters. The converter outputs correspond to synchro/resolver shaft angle information in a three or four wire AC output format.

Abstract: Frequency counter-locked-loop apparatus for controlling digitally programmable oscillators includes an arrangement for locking the output frequency of the oscillator to an accurate frequency reference. Frequency, reference and delay registers, a counter and a comparator are configured in a feedback path from the output of the oscillator to its input for continuous control of the output frequency.

Abstract: A servo loop processor (2) is a dedicated controller for use with a main central processing unit (4) (CPU), through an appropriate interface (8,10) whereby closed loop control of a servo system (22) is achieved. Servo loop parameters as well as servo motor speed and/or position are downloaded from the main CPU (4) to the servo loop processor (2) through a configuration including a microcomputer (12) so that the main CPU (4) is free to perform other tasks.

Abstract: A controller for stepper motors used in servo systems is implemented for being controlled by a microprocessor via appropriate input/output circuitry. Upon application of discrete commands, the controller produces stepper motor drive signals at a predetermined rate in predetermined drive sequences for driving one motor and for concurrently driving one of a plurality of motors. Closed loop positioning of the stepper motors using digital position feedback is achieved, as is simultaneous manual control of the stepper motors utilizing a slew stick.

Abstract: Apparatus is disclosed which is controlled via computer interface logic for converting digital signals corresponding to predetermined synchro/resolver shaft angles into analog signals for stimulus purposes, and for converting the analog signals into digital words for measurement purposes. External synchro/resolver shaft angle signals may be converted into digital words for like purposes. The apparatus has a plurality of converter channels, each of which is controlled by the computer interface logic for operation independent of the other channels. The apparatus so configured is particularly adaptable for providing stimuli and measurements which are useful in test systems applications.

Abstract: A function generator having the capability of providing a repetitive output signal with a high degree of versatility in waveform, frequency and amplitude, and with a high degree of resolution. Low frequency (76) and high frequency (86) signal are provided separately, or are combined (108) to provide an amplitude modulated output signal in either a full or suppressed carrier mode (110). Low frequency waveforms are stored (20) and high frequency and user defined waveforms are downloaded from a central processing unit (2). An output attenuator (72, 78, 82, 88) controls the output signal amplitude with a high degree of resolution. An output selective built-in test capability (116) is provided.

Abstract: Analog input/output apparatus includes a plurality of digital to analog converters (18, 20, 22, 24, 26) and a plurality of interfacing means (4, 6, 8, 10, 12, 14, 16) for interfacing the converters with a central processing unit (2). A plurality of current and voltage sources (28, 30, 32, 34, 36, 38, 40, 42) are connected to the converters for providing a plurality of voltage and current stimuli signals and monitor signals. A signal measurement channel (44, 46, 48, 52) is responsive to the monitor signals and is controlled by the interfacing means (4-16), and multiplexers (44, 46) are wrapped around the measurement channel to provide a self-calibration channel (50). The central processing unit is responsive to the self-calibration channel output for determining the correction to be applied to the stimuli signals.

Abstract: Apparatus and method for extracting the fundamental component of a complex waveshape (E.sub.T) and for determining the magnitude (V) and phase .theta. of the fundamental component are disclosed. The complex waveshape is converted into digital data relative to a reference signal (E.sub.R) and the in-phase (x.sub.1) and quadrature (y.sub.1) components of the fundamental component are determined by a graphical Fourier analysis of the digital data so that the magnitude and phase of the fundmental component relative to the reference signal (E.sub.R) can be determined.

Abstract: A transformer isolated high voltage, high power system is disclosed which is suitable for driving servo motors in servo loop control systems or the like. A D.C. current control loop is provided for preventing transformer saturation without gapping the transformer core. An output control loop is provided which minimizes signal crossover distortion and input/output phase shift. Crossover distortion adjustment is also implemented.

Abstract: A pulse generator (2) provides output pulses which are phase-synchronized to pulses from an external trigger source (3) through the use of gated delay lines (13) used as clocks. Output mode versatility is achieved by storing desired pulse output waveforms in a random access memory device (26). Expanded output resolution is achieved via an arrangement of three independent counters (10, 20, 24). A fourth independent counter (40) is used for burst counting. A pair of converters (36, 38) are used to provide an output amplitude monitor/test capability.

Abstract: A reference signal generator is controlled by a central processing unit (20) via a multibus interface (22, 24, 26) and includes a plurality of signal channels (2, 4, 6, 8) selectively responsive to external signals (E.sub.c, E.sub.m) or internally generated signals (I.sub.c, I.sub.m2, I.sub.m4, I.sub.m6, I.sub.m8) for providing carrier (12), modulating (16), or amplitude modulated (34) output reference signals (E.sub.o2, E.sub.o4, E.sub.o6, E.sub.o8) having a variety of waveforms. One of the signal channels (8) is arranged to sum the outputs of the other channels. Each of the channels includes an output attenuator (44, 46, 48, 50, 52, 56) which imparts a relatively high resolution to the output reference signals (E.sub.o2, E.sub.o4, E.sub.o6, E.sub.o8) and a circuit (54, 60, 62, 64, 66) which adjusts the range of said output reference signals. A built-in test capability (FIG. 3) is provided which permits selection and testing of the output reference signals from any one of the channels (2, 4, 6, 8).