TRDP Makes Audio Signal Devices Intelligent in Rail Vehicles
The universal audio signal device TRDP-AST for TRDP networks (Train Real-time Data Protocol) enables manufacturers and operators to perform configurations via a web server almost in real-time. For the first time, the device supports the remote uploading of up to 256 MP3 or WAV files with a maximum total playtime of up to 15 MB.
Audio signals in rail vehicles fulfill functions that are both safety-related and comfort-enhancing. For passengers, acoustic signals such as warning signals when doors are closing and automated station announcements are indispensable. Audio technology from LÜTZE Transportation GmbH supports accessibility with multilingual announcements in disabled-accessible toilets and acoustic cues for the blind when opening and closing doors. In the cab, LÜTZE signal devices enable the reliable implementation of acoustic warnings for safety-critical systems such as PZB (Point Train Control), SIFA (Safety Driving Switch), and fire alarms. Similarly, emergency communication between the train driver and train crew can be supported by automated announcements. In addition to safety-related applications, comfort functions can also be integrated, such as in the City Airport Train (CAT) Vienna. There, in the washrooms enhanced with Viennese highlights, music classics like Le Nozze di Figaro by Mozart, Wiener Blut by Johann Strauss, or the famous zither sounds from Anton Karas' The Third Man are played through audio signal devices by LÜTZE TRANSPORTATION.
Global Signaling in Use
LÜTZE TRANSPORTATION has been one of the leading global providers of audio signaling and audio accessories for rail vehicles, suited for special purposes, for many years. In addition to piezo signal devices and digital signal generators, digital audio signal devices and audio signal devices with TRDP are also available.
The piezo signal devices (buzzers) are characterized by their high efficiency and low power consumption, and are used to transmit warning signals and acoustic alarm signals. These devices are based on proven piezoelectric technology and can reproduce tones at various volumes and frequencies, with the frequency of each tone individually adjustable. It should be noted that the simultaneous output of multiple warning tones requires the installation of a corresponding number of devices.
The digital signal generators from LÜTZE TRANSPORTATION are specially designed for use in public transportation in outdoor areas, such as on suburban trains. They feature digital high-power amplifiers with an output of up to 200 W, enabling warning signals with very high sound pressure levels. The activation of the signals is carried out via 12 or 15 opto-isolated control inputs.
The microprocessor-controlled audio signal devices from LÜTZE TRANSPORTATION offer the possibility to play up to 63 audio files at six digital inputs, including realistic warnings and information in the form of speech, melodies, and signals. LÜTZE TRANSPORTATION also offers support for voice recording in a professional sound studio as a service to optimally adjust the desired sounds and signals. The specific signals and configurations are stored on the signal device either directly via a PC or with the LÜTZE Handheld Programmer using the specially developed LÜTZE AudioConfig Tool software. After installation in the vehicle, the stored configuration can only be changed with an update of the configuration software and re-uploading to the ASG. Access to the device is necessary.
LÜTZE Signal Devices now also speak TRDP
With the TRDP-AST (Audio Signal Transducer), a change in configuration and the uploading of new sound files are possible at any time and without dismantling the device. Thanks to Ethernet integration and TRDP, the signal device can be remotely controlled almost in real-time, significantly simplifying the updating and changing of sound files. For example, a vehicle could be switched from a French to an English language set in just a few minutes.
The programming of the new signal device can be done via the central computer and a user-friendly web interface. Complicated programming with special hardware and software is not required. In addition to warning tones and acoustic signals, voice recordings or music pieces in the passenger area or cab can be individually configured.
Through the web interface, all sound files can be uploaded and assigned a unique ID. Optionally, a comment can be added to each sound file. The TRDP signal device also enables the programming of complex queues, allowing certain sequences of tones to be played. Sound files can be played once or repeatedly and also interrupted. The playback can be individually delayed, and a specific volume can be set for each sound file.
Integrated Onboard Intelligence
The audio signal device is fully integrated into the TRDP (Train Real-time Data Protocol) with real-time exchange of status information, diagnostic messages, passenger information, and control commands between all devices and the central computer of a rail vehicle.
The TRDP-AST is thus able to respond to signals from devices connected to the network and, for example, play certain tone sequences when requested by the central computer. As a result, the audio signal device from LÜTZE TRANSPORTATION is very flexible in its use.
All TRDP-capable devices in the network of a rail vehicle can thus issue signalizations and information in real-time via the TRDP audio signal device. The almost delay-free signal transmission ensures that important signals, such as SIFA messages, are passed on to the vehicle driver without time loss. Additionally, the audio signal device reports back to the central computer whether the signal was successfully played in the cab. The diagnosis in the form of feedback and associated protocol data can be read out. This is a significant advantage of the TRDP-AST audio signal device from LÜTZE TRANSPORTATION, and is not possible with conventional models with digital inputs. In these older models, only a status feedback on the operating condition of the device is provided.
If multiple TRDP audio signal devices are installed in a rail vehicle, they can be grouped together via the web configuration and controlled collectively. For example, when all doors on one side of a car are opened simultaneously, all relevant signal devices for a uniform sound output can be addressed together, without needing to address each signal device individually.
The audio signal device can be easily integrated into Ethernet networks by connecting it via an RJ45 plug to TRDP. Additional wiring is not required, simplifying installation. In addition to the primary control via TRDP, the signal device offers two configurable digital inputs as a safe fallback solution. In case of a network failure, alternative signals, such as for emergency situations, can be activated via these inputs.
The integrated broadband loudspeaker produces a sound pressure level of up to 103 dB at 2.5 kHz at a distance of one meter, providing clear and penetrating acoustic signaling. Equipped with a wide-range power supply (24 to 110 V), the audio signal device is usable worldwide on rail vehicles.
The signal device is designed for an extended working temperature range from -40 °C to +70 °C and meets rail-relevant standards EN 50155, EN 50121-3-2, EN 50124-1, EN 50657, EN 61373, and the fire protection standard EN 45545-2. It also meets the EMC standard 06 of the Federal Railway Authority, allowing smooth retrofitting in existing systems.
The audio signal device, with dimensions of 92.0 mm x 135.1 mm x 48.5 mm, is suitable for mounting on DIN rails or on the rear panel, enabling flexible integration into various switch cabinets and applications
Outlook
Currently, the engineers at LÜTZE TRANSPORTATION are developing an advanced version of the TRDP-AST with Power over Ethernet (PoE). By utilizing PoE, the device is directly powered via the Ethernet cable, significantly reducing wiring effort and saving both time and cost. The need for a separate power supply is eliminated, allowing PoE-capable devices to be operated at installation locations without an extra power line.
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Authors: Daniel Herbst and Andreas Schindler and Yima Zimmermann, Product Managers at Lütze Transportation GmbH, Weinstadt
Cover picture credits: Intercom in a rail vehicle (stock image, iStockphoto)