ABNORMALITY DETECTOR OF OPTICAL TRANSMISSION SYSTEM

摘要

PURPOSE:To simply detect the abnormality of the quantity of light due to the disconnection of an optical fiber by transmitting a reference signal consisting of a discrimination pulse and a duty pulse and detecting the magnitude of the pulse width outputted from a counter. CONSTITUTION:A reference signal A consisting of a discrimination pulse Al and a duty pulse A2 is transmitted from a reference signal generation means 11 and gates G1, G2 are opened by a high frequency pulse C only when the duty pulse A2 is H or L to input a gate pulse D1 or D2 to a counter 15. The counter 15 counts up the gate pulse D1 at the time of H and counts down the gate pulse D2 at the time of L. Since the width of the pulse outputted from the counter 15 becomes small when the quantity of light is abnormally reduced and becomes large when the quantity of light is abnormally increased, the abnormality of the quantity of light is simply detected through a host CPU 16.