Programmable, tester for protection and safeguards logic functions

摘要

A programmable, tester for checking the proper operation of any of the basic protection and safeguards logic functions 1/1, 1/2, 1/3, 1/4, 2/2, 2/3 and 2/4. The m/n notation completely describes most required protection and safeguards logic functions in that n is the total number of inputs and m is the minimum number of those n inputs which must indicate a given logic state in order to cause a predetermined output. The tester simulates all possible logic input combinations and permutations and compares the logic functions output with that desired, providing an indication of a malfunction when a discrepancy is determined. Additional testing features assure the proper operation of the tester and provide the capability of sequentially testing a plurality of different logic functions.