DIGITAL TRANSMISSION EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To monitor an inter-block phase difference to discriminate the part where a fault occurs. SOLUTION: Phase difference monitor means 5-1 to 5-N and 6-1 to 6-N provided in block 2-1 to 2-N monitor the phase differences between phases of blocks themselves and those of connected blocks. That is, phases difference monitor means 5-1 to 5-N and 6-1 to 6-N issue abnormality signals in respective blocks when differences between frame phases generated by operation clock generation parts 3-1 to 3-N selected or nonselected by selection parts 7-1 to 7-N and frame phases of other connected blocks are equal to or larger than an allowable value. Discrimination parts 8-1 to 8-N discriminate an abnormal part based on these abnormality signals.