ALCMS & Smart Airfield Monitoring

Airfield Lighting Control and Monitoring System (ALCMS) is the integrated software and hardware platform that allows operators to control, monitor, and diagnose the entire AGL network from a central location. It replaces manual switching panels and local control boxes with a computerised system that communicates with every CCR, distribution panel, and, in modern implementations, even individual fixtures.

Smart airfield monitoring extends this concept with predictive analytics, asset health tracking, and integration with other airfield systems (e.g., ASDE-X, weather sensors, BMS) to create a holistic view of airfield operations. The goal is not just remote control, but intelligent, data-driven decision support for operations and maintenance.

The ALCMS's purpose is to give a single operator, from a single location, both the reach and the awareness to run an airfield's entire lighting system safely — turning what would otherwise be dozens or hundreds of separately switched circuits and local control panels into one coherent picture that can be commanded and diagnosed centrally. Its value shows up most clearly in exactly the situations where manual, distributed control would be too slow or too fragmented to trust: bringing an approach lighting system up to full intensity the moment weather deteriorates, isolating a faulted circuit before it affects surrounding operations, or pinpointing which single fixture in a long series loop has failed from a CCR's current signature alone, rather than sending a technician to walk the runway. The step from ALCMS toward "smart" monitoring extends this same purpose forward in time — using the same data stream not just to show what is happening now, but to flag what is likely to fail next, so maintenance can be planned before a fault ever reaches the control room as an alarm.

ALCMS is deployed wherever AGL infrastructure needs to be controlled and monitored:

• Air Traffic Control Tower: Primary control interface for switching circuits and intensity steps in real time.
• Maintenance Control Centre: Detailed status displays, fault logs, and diagnostic tools for engineering staff.
• Remote Monitoring Stations: Secondary displays for off-site or backup monitoring (e.g., airport operations centre).
• Mobile Devices (Tablets): Increasingly, field technicians use mobile applications to view circuit status and receive fault alerts while on the airfield.
• Integration with Other Systems: Data exchanged with surface movement radars, weather systems, and building management systems for coordinated decision-making.

The system typically includes a redundant architecture (dual servers, dual network paths) to ensure high availability.

The ALCMS server infrastructure is installed in the airfield's main equipment room or data centre, with the primary operator workstation sited in the ATC tower or control room where the switching decisions are actually made, and secondary displays or a maintenance control centre workstation installed wherever engineering staff need real-time visibility. Where a redundant, dual-server architecture is specified, the standby server is installed in a physically separate room or building on its own UPS-protected power feed, connected to the primary by dedicated replication links, so a single room-level event cannot take down both. Field-side connectivity — from CCR communication interfaces, remote I/O, and smart sensors back to the ALCMS server — rides on the airfield's existing redundant fibre and Ethernet backbone rather than requiring new cabling specific to the ALCMS itself, and integration with third-party systems (surface radar, weather, BMS) is commissioned through the ALCMS's own interface ports without those external systems needing to be co-located. Mobile access for field technicians is provisioned through the facility's Wi-Fi or cellular network rather than a dedicated installation, since the mobile application itself has no physical siting requirement beyond normal network coverage.

ALCMS is built on a SCADA (Supervisory Control and Data Acquisition) framework. It communicates with remote terminal units (RTUs) located in each CCR or distribution panel over a dedicated communication network (fiber optic, Ethernet, or serial). The RTUs acquire data from the CCRs (current, voltage, fault status, intensity setting) and execute commands sent from the control centre.

Key functional aspects include:

• Circuit Control: Turn individual series circuits on/off, select intensity steps, and change operating modes (e.g., normal, emergency, test).
• Real-Time Monitoring: Display current, voltage, power, and status of each CCR and circuit. Alarms trigger when parameters deviate from setpoints.
• Event Logging & Reporting: All operator actions, faults, and system events are logged with timestamps, providing an audit trail and data for trend analysis.
• Fault Diagnosis: Advanced systems provide fault location assistance by analysing current signatures and comparing with expected values (e.g., detecting a single fixture failure from the CCR current profile).
• Predictive Maintenance: By tracking lamp hours, switching cycles, and performance drift, the system can alert maintenance crews to impending failures before they occur.
• Cybersecurity: Modern ALCMS includes role-based access control, encrypted communications, and intrusion detection to protect critical infrastructure.

ALCMS sits at the top of the airfield lighting control hierarchy, and its own architecture is essentially the control loop the rest of the system feeds into. At the field level, remote terminal units (RTUs) inside each CCR or distribution panel acquire real-time current, voltage, fault and intensity data, and carry out on/off and step commands issued from above. That data travels over a dedicated communication network — fibre, Ethernet, or serial — back to the central SCADA server, which aggregates it, runs alarm and fault-diagnosis logic, and presents it to the controller or maintenance operator through the HMI. Commands flow the other way along the same path: an operator selecting a new intensity step or switching a circuit off issues that instruction from the HMI, the server validates and routes it to the correct RTU, and the RTU executes it at the CCR — with the resulting change reported back up the same loop to confirm it took effect.

The ALCMS platform is built as a distributed hardware and software system rather than a single physical unit: server hardware, typically rack-mounted in a control-room or equipment-room cabinet, hosts the core monitoring and control software, often duplicated as a hot-standby pair housed in separate cabinets or even separate buildings for redundancy. Field-level hardware, including remote terminal units (RTUs) or protocol converters installed within CCR cabinets and distribution panels, physically interfaces with the underlying AGL equipment, translating local signals into the Ethernet, fibre-optic, or serial communication protocols the central servers use to poll and command the field. These field units are housed in sealed, DIN-rail-mounted enclosures within the same cabinets as the CCRs and switchgear they monitor, wired directly to current sensors, contactors, and status relays. The communication backbone connecting field units to the central server, whether fibre-optic cable, structured Ethernet cabling, or a dedicated RS-485 network, is installed in conduit or duct runs alongside the primary AGL power cabling, with redundant physical paths provided on critical circuits so a single cable fault does not isolate a section of the airfield from central monitoring.