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Lead
The tech behind musical fountains
Technology has changed how musical fountains are run, and
the way in which sound & light shows are controlled, says Abhinav Singh.
 What
is common between the laser fountain at Jamshedpur, the indoor musical dancing
fountains at Wonderland Amusement Park in Bangalore, the Veegaland Amusement
Park and the interactive play fountain at Kochi, and the sound & light show
in the Andamans?
"Having been behind many dancing fountains in India, BNA is also
aiming to set up fountains and sound & light shows in the Middle East"
- V Ranganathan
Managing Director
BNA Technology Consulting |
The answer: they are all using an infotainment controller,
which has the ability to synchronise sound and visual effects. These controllers
can be integrated with different forms of entertainment such as laser shows
or sound & light shows. BNA Technology Consu-lting has developed two different
infotainment contro-llers. One, a software-based controller, is both a playback
controller and show edit controller. The second is a CD-based controller, which
only controls playback.
Infotainment solutions are popular in the tourism industry.
Having been behind many dancing fountains in India, BNA is also aiming to set
up fountains and sound & light shows in the Middle East. Says V Ranganathan,
the company’s mana-ging director, “We are planning for a strategic
alliance with some partners for a wider coverage of the market. We have already
entered into a tie-up with a company in Sharjah, UAE, for marketing our products
in the region.”
Software-based controllers
A software-based infotainment controller can be used both as a show editor and
to control playback of a musical dancing fountain. The software controller has
components such as show editor, digital fountain controller (sequencer), Opto
isolator relay interface, relay panel, hydraulic controller and audio controller.
The show editor software has a response time of one-twentieth of a second, or
50 milliseconds. A keyboard is used to activate the fountain formations or light
channels. The software provides all the features to program the songs according
to the ability of the programmer and the choreographer. The latter can hear
the songs and select suitable fountain formations which suit the beat and pitch
of the music. The software allows the choreographer to activate any fountain
formation and light effect at any particular time.
Musical-dancing fountains have evolved over decades,
and there have been different generations of products in the past.
One is analog systems, based on multi-track magnetic
tape recordings. Under this, the music is first recorded on one track,
and the tape is moved to a show controller, where it is played back
live for programming of the fountain forms, using a keyboard. The keyboard
would have specific keys for each fountain form, including its height.
The programmer physically selects a particular fountain form of a certain
height while listening to the playback of the music, and the controller
generates a unique tone code corresponding to this keystroke, and records
it on the control track. Using unique tone combinations, similar to
the DTMF (Dual Tone Multi Frequency) signalling in telephony, it is
possible to combine multiple formations at any moment of the music.
However, there are limitations to this technology as music programming
is cumbersome and difficult, and editing of the once-recorded music
is very time-consuming.
Under the new technology, music is first digitised
and stored in the digital storage media. A choreographer then analyses
the music to identify the beats, tunes and rhythm, and segments the
music into smaller segments, which would be typically of durations ranging
from a few hundred milliseconds to a few seconds. In fact, the music
can be resolved to as small an interval as 50 milliseconds, if needed.
After the segmentation of the sound track, the programmer brings individual
fountain formations into simultaneous play mode, including start and
stop; this can be synchronised to as close as 50 milliseconds. The fountain
forms, differing heights, lights and colour are added one by one, and
the control track is slowly built up. There is provision to pre-enable
a particular form to account for the varying development times of the
different formations.
Source: BNA Technology Consulting
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Brain of the fountain
The show-control software is the brain of the musical dancing fountain, and
the sequencer is the heart. The sequencer receives the signals from the PC,
interprets the signals, and routes them to their respective channels and circuits.
It is connected to the PC through a serial or USB port, and comes in different
capacities depending on the size of the fountain. The sequencer is available
in 48 channels, 96 channels and 144 channels capacity. It interprets the signals
from the computer, and routes them to the Opto isolator relay interface. It
then provides an interface between high voltage and low voltage, takes in a
low voltage signal from the sequencer, and gives a 230 V output to activate
that particular channel and circuit. The Opto interface isolates the fountain
controller from the high voltage electrical controller, and thus acts as an
in-built protector of the fountain controller.
Then there is the relay panel, an electrical panel which has contactors to control
each fountain formation and light circuit. The relay panel takes in the 230
V signal from the Opto and activates that particular contactor; the panel also
has the facility to activate the fountain formations and lights in manual mode
for day-to-day maintenance of the fountains. In addition, the relay panel has
an SFU unit as a safety requirement.
That’s not all. The hydraulic controller controls the fountain formations,
plus there’s an audio controller with an amplifier bank and matching speakers
spread over the viewer’s gallery. The audio controller is designed as per
the site and customer requirements. Audio signals from the PC are beamed across
the gallery through the audio controller.
BNA’s CD-based standby controller is an only-playback controller used for
operating the fountain. Songs are programmed through the software-based controller,
then the programmed songs are written onto a CD. This CD is played through a
CD or DVD player. The signals are fed to an audio sequencer, which is analogous
to the sequencer of the software-based controller. These signals from the audio
sequencer are fed in to the Opto. The show value of both the software-based
controller and CD player-based controller are the same.
IT vs traditional means
The traditional control system for a fountain is based on PLC (programmable
logic controller) and contactors, which are used extensively in factory or electrical
controls. These are general-purpose devices that do not provide a general framework
for implementing standardised designs. Some of these designs use even tape-based
replay systems.
There are also some manufacturers who adapt the DMX (digital multiplex) controllers
(which are used for lighting control) for implementing these infotainment solutions.
However, lights do not have the kind of latency that is characteristic of electro-mechanical
systems, hence these DMX control-based shows are not well synchronised. What’s
more, DMX-based systems depend on the PC for timing out the sequences, and also
lack the flexibility of on-line edits, calibration etc.
The latest infotainment controller is custom-made to be a dedicated general-purpose
controller meant for a range of applications where a mix of high latency, low
latency and zero latency products are used together. (For example, the dynamic
movements in a fountain have very high latency, solenoids have lower latency,
and light & sound systems have zero latency.) It has also been custom-made
for features such as online play-back-edit, which enable the system to learn
the latency of any particular channel or device, and adapt it to the entire
output. The controller also has built-in redundancy. The 50-milliseconds timing
interval of the controller provides close synchronisation. Finally, the design
is made dedicated for a variety of infotainment shows, and this enables the
user to use one type of controller for the many attractions that may be in operation
in an amusement park.
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