ALCMS Workstation

The ALCMS Workstation (Airfield Lighting Control and Monitoring System Workstation) is the operator's primary interface for monitoring, controlling, and managing the entire airfield ground lighting system. It is a high‑performance desktop computer or thin client that runs the ALCMS client software, connecting to the ALCMS server to display real‑time status, issue control commands, and respond to alarms. The workstation presents a graphical, geospatial representation of the airfield, allowing operators to view the status of every runway, taxiway, and approach lighting circuit at a glance.

Key characteristics of the ALCMS workstation include:

• High‑Performance Graphics: Equipped with powerful graphics capabilities to render large, dynamic airfield maps with real‑time status indicators, colour‑coded circuits, and animated elements.
• Dual or Multi‑Monitor Support: Typically configured with two or more high‑resolution monitors to provide an expansive view of the airfield, alarm lists, and detailed status panels simultaneously.
• Intuitive User Interface: Designed with user‑centric principles, featuring clear icons, consistent colour coding (green = on, red = fault, amber = standby), and context‑sensitive menus.
• Role‑Based Access: Supports multiple user roles (operator, supervisor, administrator) with different levels of access and control authority, ensuring that only authorised personnel can execute critical commands.

Core functions of the ALCMS workstation include:

• Real‑Time Status Display: Shows the current state of all AGL circuits, including on/off status, brightness step, current readings, and alarm conditions, updated in real‑time (typically 1‑5 second refresh).
• Control Execution: Allows operators to turn circuits on/off, adjust brightness levels, control stop bars, and execute pre‑programmed lighting scenarios (e.g., runway configurations for different approach categories).
• Alarm Management: Displays active alarms in a prioritised list with clear visual and audible indicators. Operators can acknowledge, silence, and log alarms, and drill down for detailed diagnostic information.
• Historical Data Access: Provides access to historical logs for circuit status, current readings, alarm events, and operator actions, supporting trend analysis and compliance reporting.
• Diagnostic Tools: Includes built‑in diagnostic tools for troubleshooting, such as communication status indicators, device health checks, and system performance metrics.

The workstation is typically installed in the air traffic control tower, the airfield operations room, or the maintenance control centre. It is connected to the airfield network via redundant Ethernet links, and is often configured with a UPS to protect against power interruptions.

The ALCMS workstation exists to give a single operator command and visibility over an entire airfield's lighting infrastructure from one seat, condensing what would otherwise be an unmanageable number of individual circuit states into a geospatial, at-a-glance view they can actually act on under time pressure. During a rapidly changing weather event or a runway configuration change ahead of an arrival, this consolidated view is what lets an operator make and execute a decision in seconds rather than working through dozens of separate systems.

Role-based access control exists specifically because the commands available from this workstation are safety-critical — changing a runway's lighting configuration or disabling a stop bar has real operational consequences — so the interface has to ensure that only personnel with the right authority can issue those commands, while still giving every operator the situational awareness they need to respond to alarms and monitor system health.

ALCMS workstations are used in all airfields that have a modern AGL control and monitoring system, including:

• Air Traffic Control Towers: Providing controllers with real‑time status of runway and taxiway lighting to support safe aircraft movements during all visibility conditions.
• Airfield Operations Rooms: Enabling operations staff to monitor and control AGL systems during routine operations, maintenance, and emergency situations.
• Maintenance Control Centres: Allowing engineering and maintenance teams to diagnose faults, plan maintenance activities, and verify system performance.
• Remote Monitoring Stations: Supporting off‑site monitoring and control (e.g., from a central airport operations centre) via secure network connections.
• Training Simulators: Used in training environments to familiarise operators with the ALCMS interface and procedures without affecting live systems.

The workstation is typically part of a larger ALCMS architecture that includes:

• ALCMS Server: The central data processing and storage platform.
• Network Infrastructure: Fibre optic or Ethernet switches and communication gateways.
• Field Equipment: CCRs, remote I/O, smart fixtures, and sensors.
• Peripheral Devices: Printers for alarm logging, large‑format displays for status boards, and external speakers for audible alarms.

In larger airports, multiple workstations may be deployed in different locations (tower, operations, maintenance), all connecting to the same ALCMS server and providing consistent, synchronised information across the facility.

Workstations are desk-mounted at the operator position in the ATC tower, airfield operations room, or maintenance control centre, positioned for clear sightlines to the runway/taxiway where the tower cab is the location, and wired back to the network switch on structured Ethernet cabling rather than field cable. Screen and console placement follows the room's operator ergonomics rather than a fixed airfield setout rule, but power is typically fed from the same UPS-backed supply as the ALCMS server so the operator's control and monitoring capability survives a mains interruption; remote workstations at satellite locations connect back over the airport's secure network link rather than a direct cable run to the server room.

The ALCMS workstation functions as the primary interface between the operator and the AGL system, translating complex field data into an intuitive visual representation and translating operator commands into actionable control signals:

• Data Presentation: The workstation receives real‑time data from the ALCMS server via the network (typically using TCP/IP and proprietary or standard protocols such as OPC UA, MODBUS, or IEC 61850). The client software renders this data on the screen using a geospatial map of the airfield, with colour‑coded icons and dynamic indicators that show the status of each circuit and fixture.
• Interactive Controls: Operators interact with the interface using a mouse, keyboard, or touchscreen. Clicking on a circuit element brings up a control panel with options to turn the circuit on/off, adjust brightness, or view detailed status information. Operators can also execute pre‑defined lighting configurations (e.g., "Runway 09 Approach Lighting – CAT III") with a single command.
• Alarm Handling: When the server detects an alarm condition (e.g., circuit fault, overcurrent, communication loss), it sends an alarm notification to the workstation. The workstation displays the alarm in a prioritised list, with colour coding (red = critical, amber = major, yellow = minor) and an audible alert. Operators can acknowledge the alarm, add comments, and initiate corrective actions.
• Command Execution: When an operator issues a control command, the workstation sends the command to the ALCMS server, which validates the command (checking permissions, operational constraints, and interlock conditions), formats it for the target field device, and transmits it via the communication network. The workstation then updates the display to reflect the new status once the server confirms successful execution.
• Logging and Auditing: All operator actions (logins, control commands, alarm acknowledgements) are logged by the workstation and transmitted to the server for storage in the historian database. This provides a complete audit trail for compliance, safety investigations, and performance analysis.
• User Authentication: The workstation requires operators to log in with a username and password. The server verifies the credentials and assigns the appropriate role (operator, supervisor, administrator) with corresponding permissions. This ensures that only authorised personnel can perform critical control actions.

The workstation also includes self‑monitoring capabilities, such as network connectivity status, server connectivity status, and system resource usage (CPU, memory, disk). If the workstation detects a loss of connection to the server, it displays a warning and attempts to reconnect automatically. The workstation software is designed to be resilient, with automatic recovery from network interruptions and graceful handling of server failover events.

The ALCMS workstation is built as a standard commercial computing platform housed in a desktop tower, rack-mount chassis, or all-in-one enclosure, selected to suit the control room's space and cooling arrangement. Internally, the chassis houses the motherboard, multi-core processor, memory, storage, and dedicated graphics card on standard mounting rails or trays, with cooling provided by fan-driven airflow through filtered intake vents to keep dust out of the control-room-grade electronics during continuous 24/7 operation. Multiple video outputs feed the dual or triple monitor array that forms the operator's primary display, with cabling routed through cable management channels built into the desk or console mounting. Where the workstation is deployed as a thin client connecting to a remote ALCMS server, the local unit is a smaller, fanless or low-power enclosure with reduced internal components, relying on the network connection rather than local processing power. The chassis and cabling are typically installed within a purpose-built control desk or 19-inch rack enclosure alongside an uninterruptible power supply, keeping the workstation's physical footprint integrated into the control tower or airfield lighting control room environment.