Abstract: A computer controlled apparatus for grain elevators which includes a computer with keyboard and display and suitable output devices such as a printer and which receives inputs from sensing devices such as scales and moisture analyzers and sensors and which records and retains grain transactions as the grain is weighed and unloaded and in which samples of the grain are selected and analyzed in a moisture meter. The elevator operator inputs with the keyboard particular customer numbers and other desired information and the apparatus eliminates weigh ticket writing and prints over the scale transactions automatically and provides instant decision data such as marketing data so that the accounting functions can be automatically selected.

Abstract: A phase locked loop circuit (100) for generating a periodic clock signal from a controlled oscillator circuit (130) in phase coincidence with a synchronous aperiodic data input signal is disclosed. A pulse of the data signal and a corresponding pulse of the clock signal are applied to a bistable circuit (FF1) having an output signal indicating which of the pulses occurs first in time. The pulses are further applied through delay circuitry (DLY1, DLY2) to another bistable circuit (FF2) having an output signal indicative of the magnitude of phase difference between the pulses. The output signals of the bistable circuits (FF1, FF2) are applied to a multilevel driver circuit (140) which generates an error correction signal pulse defining magnitude and direction of a correction signal to be applied to the oscillator circuit (130).