By Anthony Moody Rhys Porter Nicolas Wilson
Background Objectives Design Normal Operation Logic Failure Issues and solutions Improvements
Level Crossing: Flags as indicators Patent of Level Crossing Electronic Bells Cross-Buck “X” sign
12 Digital Inputs 4 Inputs able to run as analog 6 Relay Outputs LCD Display Operating Buttons Functions:
Design and Implement a Level crossing using analogues available in the lab and Moeller Fail safely and appropriately handle exceptional cases
Fail Safe Moeller Easy “PLC” Power Supply Strobe Light as bells
Proximity Based Train Detection Safety Conscious Design Verbose Fault/Warning Memory for Diagnosis and Reporting Some Automatic Fault Recovery Intersection Obstruction Detection 10 effective outputs from 6 SSRs Emergency Stop Fail Safe on Controller Power Loss
Wait for train Trigger warning lights Lower boom gates Set train lights accordingly throughout As train leaves do in reverse order
Simplified Underlying Logic
Loss of power to controller Sensor failure (boom gates) Emergency switch Obstructed intersection Train detection failure Erroneous train signals to boom gate
Issue: Limited outputs Solution: Use external transistor with diode or gate Issue: Potentiometer too sensitive Solution: Use rheostat in series with resistor
Moeller Expansion Module if required Active monitoring to larger control system