The functionality of information-measuring systems for remote detection of faulty parts of the undercarriage of cars in motion is considered. The features of the use of fiber-optic cables laid along the railway tracks as sensors for detecting defects in the rolling stock and infrastructure of railway lines are evaluated. The functional features of the influence of external physical influences impact on the length of the reflected wave fiber Bragg gratings. The possibility of using remote acoustic sensing to determine defects in parts and assemblies of rolling stock while the train is in motion is shown, the possibilities of joint application of the remote acoustic sounding technology with axle counters and a wheel passage registration system are noted. An assessment of the conditions for ensuring the operability and adjustment of a distributed fiberoptic line of sensors for a railway section is proposed. A scheme for the planned placement of remote acoustic sounding devices at the training ground of the Belarusian Railways has been developed. The possibility of immediate detection of defective wheelsets with a maximum allowable value of sliders exceeding 1.0 mm, as well as a break in the side frame of a wagon bogie to prevent dangerous emergencies, has been established. A method is proposed for continuous monitoring of the technical condition of rolling stock in motion, providing increased control over the serviceability of parts and units of the rolling stock.