Control systems

Claim 1

A digital computer supervised control system for monitoring and controlling a plurality of separate variables, each variable having an associated and individual measuring device giving an electrical output signal and each measuring device having an associated and individual encoder, the control system comprising: A. means for supplying data representative of said variables to a computer, said means comprising: a plurality of continuous feedback encoders each including means for supplying as an input thereto, an electrical signal, representative of a separate one of said variables, each encoder being operable according to the continuous balance feedback prin-ciple to continuously track that associated variable, and each encoder including: 1. means for comparing its respective input with a feedback signal generated by said encoder to develop a comparator output; 2. means for applying said comparator output as a digital input to a counter which comprises a plurality of flip-flop stages and which operates in a cyclic progressive code in a manner such that each unit change in count of the counter is characterized by a single digit transition in said counter; and 3. means for converting the count of said counter to said feedback signal and for applying the feed-back signal to the comparing means, and B. gating means under the control of said computer for selectively applying, as inputs to the computer, at any time, and without synchronization for any duration, the contents of the counter of at least one of the said encoders during the continuous tracking operation thereof, the gating means for each counter including enabling means associated with each flip-flop stage of that counter and the contents of that counter, as distinguished by the states of the flip-flop stages being represented in cyclic progressive code.