DATA TRANSMISSION SYSTEM, AND METHOD FOR DETECTING ABNORMALITY IN THE SAME

PROBLEM TO BE SOLVED: To provide a data transmission system capable of transmitting a transmission signal independently of an abnormal place, and to provide a method for detecting abnormality in the system.SOLUTION: The data transmission system comprises: plural detectors 10; converters 11 for converting detection signals obtained from the detectors 10, to transmission signals; plural processors 20 which perform necessary processing on the transmission signals and output the transmission signals; and a controller 15 for controlling a control target using inputted transmission signals. Transmission lines 13 and 14 interconnect the processors 20 and the controller 15 to form normal-time transmission loops independent of each other and different in transmission direction. If a processor 20a detects abnormality in a processor 20b, a transmission path switch 30a cuts off the connection between the processor 20b and the transmission lines 13 and 14 and interconnects the transmission lines 13 and 14 to form an abnormal-time transmission loop.