The PA/PIS closely integrates the audio and visual functions for conveying the desired information. The central control unit controls these functions. The system generally consists of:

A. Visual equipment

Visual equipment, consisting of saloon displays and train header and head code displays, conveys journey-related information for the convenience of passengers, both on the platform and inside the train. Based on the proven hardware and software concepts and made of ultra bright/multi-coloured LEDs, this equipment is installed at suitable locations in the train/bus to give clear visual displays. These displays can be customised with regard to their sizes, ambient lighting conditions and mounting locations. The central control unit of the passenger information system drives these displays.

B. Audio equipment

Audio equipment is used for automatic and manual announcements to passengers travelling in the train. It can also be integrated with centralised traffic controller station through radio links/GSM for emergency messages.

This equipment generally comprises:

1. Driver interface unit.
2. Public address system.
3. Automatic voice announcement unit.
4. Passenger to driver interface unit.
5. Fist/Gooseneck microphone.
6. Power amplifier unit features include automatic gain adjustment according to ambient noise conditions.

C. Central control unit

This customised electronic unit is the heart of the system and deals with the basic audio, auto-announcing and interfacing of critical functions identified by the user, like train wire interface, GSM/GPS interface, train radio interface, etc. It can be designed according to the customers application and requirements. It contains a user interface, allowing data input in the form of route data base, timetable, audio visual messages, GSM & GPS interface, interfacing with vehicle computer and signalling systems, and the like.