The Phase Motion Detector (PMD-3) monitors the direction of approaching trains from 240 to 7,500 feet and activates warning signals at the specified pre-set distance. The PMD-3 is compatible with our HXP-3 crossing processor, integrating enhanced train approach and warning capabilities at crossings. The system is available in two model configurations: The PMD-3 for stand-alone operation in single-track applications and the PMD-3R with built-in redundancy for single-track applications.