BAS Rail & Electrical Pty Ltd

Audio Player for Sydney Monorail

BAS Rail & Electrical was awarded the job to design and build an audio player for the PA system onboard the Sydney Monorail. The customer, Veolia Transport, the owner and operator of the Sydney Monorail, had very specific requirements, which made it impossible to find an off the shelf system to suit.

The audio player should be able to play good audio quality messages, either activated by the driver or automatically triggered at predefined locations around the track.

The device, which now have been installed on the Monorails, can play up to 15 driver initiated messages and 24 automatic messages. As the messages are stored on a SD memory card, the memory capacity far exceeds the required space. All audio files are stored as .WAV files and on the same memory card a text file with the locations of the automatic triggered messages is also stored.

The location of the Monorail can be determined by

a) Using the station identification flags for the onboard autopilot.

b) Using the pulses from one of the fron wheel tacho generators to calculate the location between the flags.

In this way, the trigger point for a message can be set within a couple of metres.

Main data:

Supply voltage: 24VDC (from vehicle's battery)

Audio: 12 bits D/A conversion at 22 kHz sample rate. Filter cut-off frequency 10 kHz.

Data storage: SD card, FAT16 formatted

Separate driver's panel with monitor speaker and control switches