Test set for a navigational satellite receiver

Claim 1

A digital card tester section of a test set for detecting the reduced capabilities of an associated navigational satellite receiver, said digital card tester section being configured to generate signals (signatures) for testing and isolating faults in a predetermined number of digital system cards of the associated navigational satellite receiver according to a predetermined program, said digital tester card section comprising: a read-only memory (ROM) being configured to store the predetermined program which corresponds to at least the signatures of the predetermined numbers of digital system cards under test; a random access memory (RAM) being configured to permit data, in the form of the signatures, and in the form of responses, from the predetermined number of digital cards under test to be stored or retrieved at comparable intervals according to predetermined periodic signals; a system clock for generating the predetermined periodic signals for proper synchronization of signatures, responsive signals, and timing signals; a microprocessor operatively connected to said ROM, to said RAM and to said system clock for decoding and executing the predetermined program stored in said ROM; connection means for operatively connecting the predetermined number of digital system cards under test to said microprocessor and said RAM; intialization means operatively connected to said microprocessor for instituting initialization thereof, and of said ROM and said RAM; and display means operatively connected to said microprocessor for displaying the output of the RAM for the predetermined number of digital system cards, and for indicating the faults therein.