JPS6468047A - Line monitoring device - Google Patents

Abstract

PURPOSE:To facilitate a countermeasure in the event of the abnormality of a communication system by providing an abnormality informing means to generate a timing signal for informing the occurrence of an abnormality to one or both of the two communication equipments. CONSTITUTION:In a line monitoring device 4 which is connected to a communication line 3 between the two equipments 1, 2 to communicate and traces communication data and the occurrence of abnormality, the abnormality informing means 4a that generates a timing signal to inform the occurrence of an abnormality to one or both of the equipments 1, 2 is provided. The device 4, at the time of fetching communication data set in accordance with tracing condition, holds a determined quantity of communication data yet fetched, and at the same time issues a signal from its means 4a to the equipment that communicates. As a result, both the communication data of the communication system at the time of the occurring of an abnormality and the state of the communication equipments can be held simultaneously, hence a countermeasure against the abnormality can be easily executed.