HMI
Human Machine Interface
A graphical or physical interface that enables railway operators and maintainers to monitor system status, receive alarms and interact with equipment and control systems.
Detailed explanation
A Human-Machine Interface (HMI) provides the interface between personnel and automated railway equipment or control systems. It presents operational information in a form that allows users to understand system conditions and, where authorised, issue control commands.
An HMI may display equipment status, process values, alarms, trends, system diagrams and diagnostic information. Depending on the application, users may also operate equipment, acknowledge alarms, change permitted settings or initiate predefined control sequences.
In railway systems, HMIs are commonly associated with Supervisory Control and Data Acquisition (SCADA), Programmable Logic Controllers (PLCs), Building Management Systems (BMS), traction power control, tunnel ventilation, station systems and other infrastructure control systems.
HMIs can be provided locally at equipment rooms, substations or stations, or centrally within an Operations Control Centre (OCC) or maintenance control facility.
The design of an HMI should provide operators with clear and consistent information while reducing the potential for human error. Important considerations include alarm prioritisation, access control, cybersecurity, usability, equipment identification and the clear presentation of abnormal or emergency conditions.
Railway applications
mainline, high_speed, metro, light_rail, freight, depot, station
Standards and references
IEC 62443 series; IEC 61131 series where applicable; applicable railway control, SCADA, human factors and project-specific requirements