The Needle Position Detection (RPA-TM29) is a device designed to monitor the position of both needles of a switch;
The RPA-TM29 is intentionally located at the top of the crosshead so as not to interfere with the automatic movement of the switch, and is integrated with the two contrasts by means of two stringers that ensure isolation between the two parts relative to the contrasts.
The Needle Position Detector device (RPA-TM29) is used to control one position of the two needles and has an electrical circuit, separate from the position control circuit, which confirms to the Light Switch Indicator Signal that the electrical control of the needle has been achieved.
The RPA informs the user (Movement Manager, Train Leader or Engineer) through the Luminous Switch Indicator Signal that the switch can be safely crossed by the train.
