Here are some typical rail systems which you could integrate
Control Systems
Lifts, Escalators and Travelators
Building Management System
Fire Alarm Management System
Tunnel Ventilation
Security Systems
Closed Circuit Television
CCTV Data Analytics
Access Control
Perimeter Security
Intruder Detection
Utilities
Energy Management Systems
Low/High Voltage Control and Monitoring
Water Management System
Local Area Network
Passenger Sensitive Equipment
Public Address/Voice Alarm
Passenger Help Points
Customer Information Systems