The context is the supply of a SCADA system for a light guided subway line with integral automation (no staff on board trains and in the stations), called Milano Linea 5, for the city of Milan.
The SCADA system allows the acquisition, collection and processing of data coming from Peripheral Posts (initial phase 9 stations and 1 depot), with the aim of centralizing all the information about the controlled plants.
In brief, via the Control Center (CC) and the Emergency Center (CS), the SCADA system allows monitoring and supervision of the peripheral equipment, providing all status and alarm information and allowing commands to be given that are required to manage the equipment.
This peripheral equipment refers to subsystems of:
- System electrical power plants (electrical substations, MV/LV transformation cabins...)
- Auxiliary technological systems (normal station lighting systems, station/tunnel ventilation systems, emergency fire systems, water bail out systems, alarms and statuses coming from vehicle equipment...).
This goal has been reached with the supply of RTUs (Remote Terminal Units) comprising hardware (PLC, I/O boards, serial boards...) and software for managing the station equipment. These RTUs are connected to the field terminal boards and are also connected via the Ethernet port to the communication network. Similarly, the CC (Control Center) and the CS (Emergency Center) are connected by Ethernet connection to the communication network to be able to speak with all the RTUs.
The SCADA system mainly has the task of visualizing all the field information in graph format, and sending commands decided by the operator. The system can also manage and propose macro-command sequences to the operator, depending on the system conditions, in particular:
- for reconfiguration of the network depending on the fault that has occurred
- for sending ventilation strategies depending on the position and direction of the train.
The System never makes autonomous decisions and therefore does not automatically send commands for events that have been detected; confirmation from the operator is always required to start up the proposed sequences of commands.