Abstract: The identity of horses is established by optically scanning the four "chestnuts" located on the insides of their legs to generate digital numbers corresponding to the width, height and area of each chestnut. These numbers are encoded digitally with an application number assigned to the individual horse and the serial number of the equipment performing the scan to produce a code which is then stored on tape within a tape recorder. The code is thereafter transmitted to a central data bank for future reference so that the identity of the horse can be subsequently checked to prevent fraudulent and mistaken substitution of horses. The apparatus and method is also useful in identifying lost horses and in controlling theft and disease.

Abstract: This interrogation system monitors the status of a plurality of protection zone transducers by repeatedly supplying a series of sequential interrogation pulses thereto sufficient to address and scan every transducer associated with a protection zone. Reply pulses are received from a transponder associated with a protection zone transducer and the reply pulses received over a selected number of prior sequential scans form a response pattern from which the condition of each transducer and its protection zone is determined. At least three conditions may be determined from the reply response pattern, including an alarm condition, a normal condition, and an out-of-service condition. Information relative to each transducer and its respective protection zone is stored in the form of bits at memory addresses corresponding to the count of the protection zone transducer from which that information is received.