Device for monitoring data traffic on a bus system

摘要

An adapter (A) is coupled via a modem (Md1) with the bus system which forwards the send and receive data telegrams to a personal computer (PC) which evaluates them. This adapter (A) is controlled by the modem (Md1) and the personal computer (PC) in such a way that it is able to set a gate circuit (T), via which the data telegrams are forwarded to the personal computer (PC), during the actual telegram period only. The start of the telegram is indicated to the adapter (A) by means of a control signal originating in the modem (Md1) or a data receiving/data transmitting device (MC1), and the end of the telegram is indicated by a control signal originating in the personal computer (PC) and derived from the telegram. The device is particularly suitable for carrying out testing and maintenance tasks on a transmission system used in railway systems. <IMAGE>