Cerberus Level Crossing Monitor. (LXM)ProductsLevel Crossing Monitor Tweet Overview Level Crossing Monitor The level crossing monitor is as required by Railcorp for installation at level crossings. It comes complete with I/O and ADC boards. Related Products8 way Individual Output opto-Isolator boardCable Set for Level Crossing Monitor.12V Vital Indication Optoisolator (VIO)32 way Individual Input Optoisolator