Method of generating and transmitting digitally distorted test signals

Abstract

A microprocessor controlled test system generates and transmits distorted digital signals to a system under test by expanding a bit pattern, representative of a character to be transmitted, by an integer multiple of expansion. Selected bits of the expanded bit pattern are toggled from one logic level to another under program control to produce a distorted expanded bit pattern. The distorted expanded bit pattern is clocked out of the test system to the system under test at a rate equal to the integer multiple of expansion times the baud rate of the system under test. The resolution of the test signal can be varied by changing the integer multiple of expansion along with the rate at which the test signal is clocked out of the test system. The invention is useful in testing and adjusting a teletypewriter.

Dependencies are inferred from the claim text.