METHOD OF MONITORING SUITABILITY OF A TRANSMISSION PATH FOR TRANSMISSION OF DIGITAL DATA SIGNALS, AND APPARATUS FOR USE IN CARRYING OUT THE METHOD

摘要

-10-Abstract of the DisclosureA transmission path is monitored for its suit-ability for transmission of digital data by trans-mitting over the transmission path a video test signalwhich includes a horizontal sync pulse and at leastone half-cycle of a generally sinusoidal pulse occur-ring at a predetermined time after the sync pulse, thegenerally sinusoidal pulses being inverted in alter-nate lines or alternate fields of the video testsignal. The signal received at the other end of thetransmission path is displayed on an oscilloscope-typeCRT device having its horizontal sweep triggered bythe horizontal sync pulse, so as to superimpose thealternate generally sinusoidal pulses. The configura-tion of the generally eye-shaped area resulting fromsuch superimposition depends on the suitability of thetransmission path for transmission of digital data.