PLCs Keep Trains Running

This article discusses the City of Milpitas, California's move to integrate its new light rail system with traffic light controls at four different 4-way intersections. The goal of this effort was to allow trains to pass through each intersection safely without slowing or stopping for normally-operating auto traffic. To meet this need, five IDEC MicroSmart Pentra PLCs with digital I/O modules were purchased and interfaced to traffic light controllers at each intersection. The PLC's Ethernet port allows for remote monitoring and communication, and it can expand as needed. The authors describe the installation and functioning of the MicroSmart PLC, and they suggest that PLCs could replace traffic light controllers, thus adding flexibility to the traffic control system and improving communications from the control system to the central traffic control and monitoring system.


  • English

Media Info

  • Media Type: Print
  • Features: Photos;
  • Pagination: pp 12, 14
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01538526
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 1 2014 12:10AM