ASL understands Rail

ASL has established itself as a leader in the rail industry, with Public Address and Voice Alarm installations at over 3000 stations, and with ASL long line control spanning hundreds of stations.

ASL specializes in designing solutions for rail applications, collaborating closely with rail operators and integrators to meet relevant standards and requirements while addressing specific needs. Our systems have been installed in thousands of locations, making them a perfect fit for busy railway stations, ensuring passenger protection, information, and entertainment.

Passenger Demand

Railway stations, be they Main Line or Metro, Underground or Overground, have multiple functions and play a crucial strategic role.

As environmental concerns and the necessity to reduce carbon emissions and combat climate change continue to grow, more individuals are opting for public transportation as a means to lower their carbon footprint. Rail networks are usually viewed as a more eco-friendly alternative. Consequently, the demand for public transportation, including rail, is expected to rise. Therefore, it is more critical than ever to have reliable safety and security systems in place at railway stations.

Focus on Rail and Rail Safety

ASL places great emphasis on the rail market and we design our products in accordance with the most rigorous safety standards worldwide, such as EN 54, CSA, and UL, as well as meeting local pre-approvals like Network Rail’s PADS in the UK and TransQ throughout Scandinavia. By focusing on the rail sector, we develop products tailored to its specific needs. Our range includes dynamic volume control, platform microphones, and radio microphone systems.

Long Line Solutions

ASL has developed Public Address and Voice Alarm equipment that can operate remotely over long distances, providing optimal performance in even the most challenging environments and remote stations. The PAVA products also feature remote system monitoring and control. ASL’s Long Line Public Address (LLPA) and Customer Information System (CIS/PIS) solutions, available through the iVENCS platform, allow rail operators to manage the PA or CIS needs for an entire network at once, across multiple stations, lines, and interchanges.

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We’re trusted by:


Train Stations


Train Stations in Norway Protected


London Underground Stations Protected


Informed Annually


Protecting Passengers and Employees

ASL brings over 25 years of expertise in the design and development of Public Address and Voice Alarm products tailored to the transportation market, providing assurance to customers. You can trust ASL’s solutions to function flawlessly and consistently over the system’s lifespan.

Our PAVA systems are engineered to convey critical messages precisely where they are required and at the right time

Dynamic Ambient Noise Volume Control during Annoucements


The DANS01 dynamic ambient noise sensor, together with ASL’s powerful algorithms, enables automatic adjustment of Public Address (PA) volume levels in real-time. By capturing audio from the PA zone and transmitting it back to the ASL router, the noise sensors allow for precise control of volume levels in response to varying noise levels, even during announcements. The digital signal processor (DSP) in the router distinguishes between broadcast audio and ambient noise, facilitating accurate adjustment of volume levels. The DSP also supports various parameters, such as threshold, attack, and hold, providing precise control and site customization.

The DANS noise sensors are particularly suitable for deployment on railway platforms, where the background noise level can change quickly, for example, when a train passes. The system ensures that the audio remains clear and comfortable, while also addressing any noise abatement concerns during quieter periods in between busy loud periods

Easy Migration to ASL

ASL recognizes that migrating to a new PA system can be a gradual and risky process. Therefore, ASL systems can effectively operate with existing third-party PA systems either temporarily during a changeover phase or permanently, providing a predictable risk management strategy.

ASL’s equipment boasts analogue audio inputs and IP LLPA control, which facilitates seamless migration, even during the installation of a brand new ASL LLPA system with an iVENCS control front end.

Low Operational Costs

ASL’s systems have a track record of proven reliability, with many first-generation systems still functioning today. The extended and dependable product lifespan results in lower ownership costs and reduced whole-life expenses.

Moreover, the systems’ power supplies and amplifiers are highly efficient, thereby decreasing overall energy usage and cooling needs for equipment rooms.

Additionally, the amplifier cards in ASL’s systems are hot-swappable, reducing the need for costly nighttime service visits.

Entertaining Passengers

ASL’s professional audio PAVA systems deliver exceptional quality background music, guaranteeing a consistent and calming customer experience while simultaneously upholding the highest levels of station safety.

Local control of music sources and volume empowers tenanted areas to create unique and personalized ambiences without the need for a separate system, while still enabling station staff to maintain overall control.

Active Array Speaker Interfacing

Connecting to Active Array Speakers is effortless, and includes the ability to monitor the speakers. ASL routers incorporate analogue line level outputs plus specialized audio monitoring tones, enabling end-to-end audio path monitoring.

Cyber Security Package

Role of Cyber Secure Audio in Safety and Security Applications is imperative, especially for critical infrastructure facilities.

No single measure will ever be enough. You need an approach and commitment like Zenitel’s that covers all levels simultaneously.

A comprehensive Cyber Package like ASL/Zenitel’s V5 can significantly bolster your security posture, offering multiple safeguards and best practices to help detect and prevent attacks as they occur, whilst ensuring compliance enabling products to be sold.

iVENCS Long Line PA and Customer Information System Control

SL’s iVENCS Control System offers robust Long Line PA controls and can integrate seamlessly with any train control or signaling system, including Darwin.

To achieve integrated PA and Customer Information Display messaging, a display module can be easily added to an existing LLPA system. Alternatively, additional modules such as CCTV, Help Points, or SCADA can be integrated to form a comprehensive whole-line control system.

Sector-Specific Products

ASL’s industry-specific products are the result of our close collaboration with customers and end users, innovative technology, and the extensive railway expertise of our experienced team. Several examples of this include our products designed in partnership with Network Rail and Transport for London (TfL).

LUL Operator using the RPA01 - ASL image
ILP02 Onsite - ASL Image

Radio Microphones

ASL’s RPA01 handheld radio microphone transmitters, along with supporting receivers, chargers, and radio antennae, are in continuous use on the London Underground network. These radio microphones were designed in partnership with TfL to meet London Underground’s specific requirements. The RPA radio microphone system is a testament to ASL’s capability to create tailored solutions for its customers.

Induction Loop Panels

The ILP02 Induction Loop Panel from ASL is a solution designed to provide clear announcements for individuals with hearing impairments, which can be heard through their hearing aids or cochlear implants. Developed in collaboration with TfL, the ILP02 is a dependable and simple-to-install system that delivers local induction loop coverage for platform and station information boards. The loop panels are powered by standard ASL 100V PAVA amplifiers, and are mounted above information boards, integrated seamlessly with the board frames, or located nearby on the ceiling.

These induction loop panels are currently widely deployed throughout the London Underground.


Vandal-Resistant Microphones

ASL offers a line of SAP rail-specific platform microphones that are enclosed in lockable, stainless-steel wall-mounting boxes rated IP65 for protection against vandalism and environmental factors, making them a practical choice for use in public spaces. The SAP02 model is a single-zone microphone, while the SAP03 boasts ten function and zone selection buttons. Additionally, the SAP02 can house an ASL RMR02 Radio Microphone Receiver to allow radio microphone announcements in addition to the standard fist microphone announcements. For emergency situations, the EAP01 variant of this microphone is available in a red color.

These microphones are extensively utilized throughout the London Underground network


The iVENCS Control Software is a truly open and intuitive integrated management platform

iVENCS - LLPA, Long Line CIS, and Station or Line Management System

ASL’s enhanced iVENCS Line and Station Management System provides integrated distributed control

The iVENCS Control System has recently received an entire technology and GUI upgrade, consolidating its place at the forefront of station and line management.

The iVENCS Line and Station Management System (LSMS) provides the ability to control and monitor all aspects of Line, Depot, Station and On-Train systems, with full integration with your Train Control and Signalling System. The LSMS can provide powerful OCC Operational Control Centre and local station workstations, plus Line Overview Video Walls which combine alarm and status reporting with CCTV views, and can also be combined with the signalling system’s line map. Integrating the iVENCS LSMS with your Train and Signalling Control system enables the trains to be managed at the required Safety Integrity Level, while iVENCS provides the operators at the OCC and at the stations with powerful and simple to use telecoms and security controls.

The award-winning and unique true 3D GUI can show a whole line map with drill down to accurate, fully scaled models of individual stations. The model’s pan, tilt, rotate and zoom controls allow the user to move the viewpoint at will, to any part of the 3D station models and to any floor, with seamless viewing from any position. This avoids other system’s need to split the station map GUI into multiple small 2D maps and false-3D building plans, requiring the operators to switch between many different maps in order to operate the station’s equipment.

Key Features:

  • Award-winning 3D or traditional 2D GUI
  • System schematics and dedicated subsystem controls
  • Consistent and simple to use functionality, for multiple systems
  • Ability to provide advertising content onto displays
  • Remote Condition Monitoring
  • Distributed processing with multi-site redundancy
  • Modular system architecture; easily expandable
  • Cross-platform support
  • No ongoing license cost

Line and station operators need to monitor an ever-increasing number of subsystems, from fire detection to CCTV, PA to information displays, access control to intruder detection, and far more. ASL’s award-winning iVENCS Control System empowers both managers and staff to simultaneously control a multitude of systems. Via the intuitive 3D user interface, operators can keep a constant eye on the public and on the status of equipment around the station or along an entire line and on the trains. The operators are able to remotely control devices, and be alerted to any faults and devices that are in need of investigation.

iVENCS makes public and staff communications easier to manage, through synchronised PA and CIS display messaging, auto-scheduled announcements, intelligent message builders and multilingual messaging capability. iVENCS can give complete control of passenger and staff information boards and advertising displays.

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