Abstract: An information transmission system is provided for railway vehicles wherein optical transmission between cars of trains is preformed. A predetermined signal corresponding to information to be sent from a transmitting portion is added in succession to the information. The information is then transmitted and a receiving portion receives the information and the additional signal. The receiving portion compares the information and the additional signal to detect a transmission error. When an error rate has exceeded a predetermined value, a predetermined display signal is provided. Also, the transmitting and receiving portions are coupled to an alternative data transmission path.

Abstract: In a car data transmission device installed in cars to transmits data through the cars by means of optical fibers, optical fiber lines for data transmission are provided to be looped in duplex through a row of cars; each of cars is provided with optical fiber cables, each receiving therein the duply looped optical fiber lines as one unit whose data transmitting direction different each other; and jointing optical fiber cables are placed between the adjacent cars to pass the duply looped optical fiber lines as one unit received in the optical fiber cable placed in each of the adjacent cars whereby interruption of the data transmission lines is prevented even though a trouble of transmission such as breaking of one of the jointing optical cables occurs.

Abstract: A light transmission system for a train which includes sub-train compositions. Ths subtrain compositions each have end vehicles, one of which forms a head and the other of which forms a tail with respect to the moving direction of the train. The end vehicles each include a central station responsive to a first command signal from the front platform of the train to perform a central function for producing a second command signal and responsive to the second command signal to perform a terminal function which passes therethrough any input signal when an adjacent central station is found to be connected thereto and which returns any input signal when no adjacent central station is found to be connected thereto, thereby forming a complete signal transmission path in the train.

Abstract: An automatic vehicle testing apparatus in which data representing conditions of units to be controlled are transmitted through optical transmission lines between a central station and terminal stations mounted on vehicles, which may be railroad cars. The central station can be placed in an automatic test mode. A test controller installed at a test location is operated to place the central station in the test mode. A response signal generating unit for operating each of the units in the vehicles and a monitoring unit for monitoring operations thereof are connected between each terminal station and the respective unit to be controlled. The data in the automatic test mode is transmitted through the optical transmission lines.