Danish Interpretation Systems DCS 6000 User manual

DCS 6000
User Manual
Danish Interpretation Systems DIS
Digital Conference System
DCS 6000
Digital Infrared Wireless
Language Distribution
System

Danish Interpretation Systems User Manual
Copyright © 2005 DIS DCS6000 DIGITAL IR SYSTEM REV B.DOC 03-05-2006
No part of this publication may be reproduced or utilised in any form or by any means without permission in writing from the
publisher.

Danish Interpretation Systems User Manual
Copyright © 2005 DIS DCS6000 DIGITAL IR SYSTEM REV B.DOC 03-05-2006
No part of this publication may be reproduced or utilised in any form or by any means without permission in writing from the
publisher.
1 List of Contents
1 List of Contents..................................................... 3
2 Important .............................................................. 5
2.1 Important Safeguards................................. 5
2.2 Installation precautions.............................. 5
2.3 Cleaning ....................................................... 5
2.4 Repacking .................................................... 5
2.5 Warranty...................................................... 5
3 System description and planning......................... 6
3.1 System overview.......................................... 6
3.1.1 Infra-red transmitter................................ 6
3.1.2 Infra-red radiators ................................... 6
3.1.3 Infra-red receivers................................... 6
3.2 System technology....................................... 6
3.2.1 IR radiation............................................. 6
3.2.2 Signal Processing.................................... 7
3.2.3 Quality modes......................................... 7
3.2.4 Carriers and channels.............................. 8
3.3 Aspects of infra-red distribution systems.. 9
3.3.1 Directional sensitivity of the receiver..... 9
3.3.2 The footprint of the radiator.................... 9
3.3.3 Ambient lighting................................... 10
3.3.4 Objects, surfaces and reflections........... 10
3.3.5 Positioning the radiators ....................... 11
3.3.6 Overlapping footprints and multipath
effects 12
3.4 Planning an DCS 6000 Digital infra-red
radiation system...................................................... 13
3.4.1 Rectangular footprints........................... 13
3.4.2 Planning radiators ................................. 14
3.4.3 Cabling.................................................. 14
3.5 Setting the radiator delay switches.......... 15
3.5.1 System with one transmitter.................. 15
3.5.2 System with two or more transmitters in
one room 17
3.5.3 System with more than 4 carriers and a
radiator under a balcony........................................19
3.6 Testing the coverage area..........................19
3.6.1 Testing during installation.....................19
3.6.2 Testing during a meeting.......................19
3.6.3 Testing all positions and directions .......19
3.6.4 Bad coverage.........................................19
3.6.5 Black spots ............................................19
3.6.6 Interference from IR systems ................20
4 DT 6008 & DT 6032 Transmitters.....................21
4.1 Description .................................................21
4.2 Installation..................................................22
4.3 Connections................................................22
4.3.1 Connecting the DCS 6000 Conference
System 22
4.3.2 Connecting other external audio sources
22
4.3.3 Connecting an emergency signal...........22
4.3.4 Connecting to another transmitter .........23
4.4 Using the configuration menu...................24
4.4.1 Overview...............................................24
4.4.2 Navigate through the menu ...................25
4.4.3 Examples...............................................26
4.5 Configuration and operation....................30
4.5.1 Start-up..................................................30
4.5.2 Main menu.............................................30
4.5.3 View transmitter status..........................30
4.5.4 View fault status....................................31
4.5.5 Set monitoring options ..........................32
4.5.6 View version information......................32

Danish Interpretation Systems User Manual
Copyright © 2005 DIS DCS6000 DIGITAL IR SYSTEM REV B.DOC 03-05-2006
No part of this publication may be reproduced or utilised in any form or by any means without permission in writing from the
publisher.
4.5.7 Set transmission mode...........................33
4.5.8 Set number of channels .........................33
4.5.9 Set channel quality and assign inputs to
channels 34
4.5.10 Set channel names .................................35
4.5.11 Disable or enable carriers......................35
4.5.12 View carrier assignments ......................36
4.5.13 Configure auxiliary inputs.....................36
4.5.14 Set sensitivity of the inputs....................37
4.5.15 Enable / disable IR-monitoring..............38
4.5.16 Enable / disable headphone output........38
4.5.17 Choose transmitter name .......................38
4.5.18 Reset all options to factory default values
38
5 Digital Radiators .................................................39
5.1 Medium and High Power Radiators ........39
5.1.1 Description ............................................39
5.1.2 Radiator status indication ......................40
5.1.3 Mounting the radiators ..........................40
5.1.4 Connecting radiators to the transmitter..43
6 Digital Receivers..................................................44
6.1 Description .................................................44
6.2 Operation....................................................44
6.3 Reception test mode...................................45
6.4 Receiver headphones................................. 45
7 Troubleshooting..................................................46
8 Typical schematics..............................................48
9 Technical Specifications ..................................... 49
9.1 System Specification..................................49
9.2 Infra Red Transmitters System
Specification ............................................................50
9.2.1 DT 6008 and DT 6013 Infrared Digital
Transmitter............................................................ 50
9.3 Radiators and Accessories........................51
9.3.1 RA 6013 Medium and RA 6025 High
Power Radiators.................................................... 51
9.3.2 WB 6000 Wall Mounting Bracket ........ 51
9.4 Receivers & Battery Packs .......................52
9.4.1 DR 6004, DR 6008 & DR 6032 Digital IR
Receivers52
9.4.2 NiMH Battery Pack............................... 52
9.5 Connection details.....................................53
9.5.1 Mains cables..........................................53
9.5.2 Audio cables..........................................53
9.5.3 Earphones.............................................. 53
9.5.4 Emergency switch.................................53
9.6 Accessories (to be ordered separately) .... 54
9.7 Guaranteed rectangular footprints..........55

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2 Important
2.1 Important Safeguards
Prior to installing or operating this product always
read the Safety Instructions which are available as a
separate document.
2.2 Installation precautions
Do not install the unit in a location near heat sources
such as radiators or air ducts, or in a place exposed to
direct sunlight, excessive dust or humidity, mechanical
vibration or shock.
To avoid moisture condensations do not install the unit
where the temperature may rise rapidly.
2.3 Cleaning
To keep the cabinet in its original condition, periodically
clean it with a soft cloth. Stubborn stains may be
removed with a cloth lightly dampened with a mild
detergent solution. Never use organic solvents such as
thinners or abrasive cleaners since these will damage the
cabinet.
2.4 Repacking
Save the original shipping cardboard box and packing
material; they will become handy if you ever have to
ship the unit. For maximum protection, re-pack the unit
as originally packed from the factory.
2.5 Warranty
The individual units in the DCS 6000 system are
minimum covered by 12 months warranty against defects
in materials or workmanship.

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3 System description and planning
3.1 System overview
DCS 6000 Digital IR is a system for wireless distribution
of audio signals via infra-red radiation. It can be used in
a simultaneous interpretation system for international
conferences where multiple languages are used.
To enable all participants to understand the proceedings,
interpreters simultaneously translate the speaker’s
language as required. These interpretations are
distributed throughout the conference venue, and
delegates select the language of their choice and listen to
it through headphones.
The DCS 6000 Digital IR system can also be used for
music distribution (mono as well as stereo).
Figure 3.1-A DCS 6000 Digital IR system overview (with DCS
6000-system as input)
The DCS 6000 Digital IR Language Distribution System
comprises one or more of the following:
3.1.1 Infra-red transmitter
The transmitter is the core of the DCS 6000 Digital IR
system. Two types are available:
•DT 6008 with inputs for 8 audio channels
•DT 6032 with inputs for 32 audio channels
3.1.2 Infra-red radiators
Two types of radiators are available:
•RA 6013 medium-power radiator for small/ medium
conference venues
•RA 6025 high-power radiator for medium/large
conference venues
Both types can be switched between full and half power
use. They can be mounted on walls, ceilings or floor
stands.
3.1.3 Infra-red receivers
Three multi-channel infra-red receivers are available:
•DR 6004 for 4 audio channels
•DR 6008 for 8 audio channels
•DR 6032 for 32 audio channels
They can operate with a rechargeable NiMH battery pack
or with disposable batteries. Charging circuitry is
incorporated in the receiver.
Note: The charging unit used for charging the receivers
fitted with a rechargeable NiMH battery pack as well as
the rechargeable battery pack will not be available before
year 2006.
3.2 System technology
3.2.1 IR radiation
The DCS 6000 Digital IR system is based on
transmission by modulated infra-red radiation. Infra-red
radiation forms part of the electro-magnetic spectrum,
which is composed of visible light, radio waves and
other types of radiation. It has a wavelength just above
that of visible light. Like visible light, it is reflected from
hard surfaces, yet passes through translucent materials
such as glass.
The infra-red radiation spectrum in relation to other
relevant spectra is shown in Figure 3.2-A.

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100
75
1
42
50
25
0400 500 600 700 800
5 3
900 1000 nm
%
1 Daylight spectrum
2 Sensitivity of the human eye
3 IR radiator
4 Sensitivity of IR sensor
5 Sensitivity of IR sensor with daylight filter
Figure 3.2-A Infra-red radiation spectrum in relation to other
spectra
3.2.2 Signal Processing
The DCS 6000 Digital IR system uses high frequency
carrier signals (typically 2-8 MHz) to prevent
interference problems with modern light sources (see
section 3.3.3). The digital audio processing guarantees a
constant high audio quality. The signal processing in the
transmitter consists of the following main steps (see
Figure 3.2-B):
1. A/D conversion - Each analogue audio channel is
converted to a digital signal.
2. Compression - The digital signals are compressed
to increase the amount of information that can be
distributed on each carrier. The compression factor
is also related to the required audio quality.
3. Protocol Creation - Groups of up to four digital
signals are combined into a digital information
stream. Extra fault algorithm information is added.
This information is used by the receivers for fault
detection and correction.
4. Modulation - A high frequency carrier signal is
phase-modulated with the digital information
stream.
5. Radiation – Up to 8 modulated carrier signals are
combined and sent to the IR radiators, which convert
the carrier signals to modulated infra-red light. In
the IR receivers a reverse processing is used to
convert the modulated infra-red light to separate
analogue audio channels.
In the IR receivers a reverse processing is used to
convert the modulated infra-red light to separate
analogue audio channels .
3.2.3 Quality modes
The DCS 6000 Digital IR system can transmit audio in
four different quality modes:
•Mono, conference quality, maximum 32
channels (standard quality)
•Mono, Hi FI quality, maximum 16 channels
(premium quality)
•Stereo, conference quality, maximum 16
channels (standard quality)
•Stereo, Hi FI quality, maximum 8 channels
(premium quality)
The conference quality mode uses less bandwidth and
can be used for transmitting speech. For music the HI-FI
quality mode gives near CD quality.
A/D Conversion
& Compression
A/D Conversion
& Compression
Audio
Channel
Audio
Channel
Protocol Creation
& Modulation
4x Carrier (to IR Radiators)
4x
Figure 3.2-B Overview of the signal processing (for one carrier)

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3.2.4 Carriers and channels
The DCS 6000 Digital IR system can transmit up to 8
different carrier signals (depending on the transmitter
type). Each carrier can contain up to 4 different audio
channels.
The maximum number of channels per carrier is
dependent on the selected quality modes. Stereo signals
use twice as much bandwidth as a mono signal, premium
quality uses twice as much bandwidth as standard
quality. Per carrier a mix of channels with different
quality modes is possible, as long as the total available
bandwidth is not exceeded.
The table below lists all possible channel combinations
per carrier:
Figure 3.2-C Directional characteristics of the receivers
Channel Quality
Mono
Conference Mono
Hi-Fi Stereo Conference Stereo Hi-Fi Bandwidth
4 4 x 10 kHz
2 1 2 x 10 kHz and 1 x 20 kHz
2 1 2 x 10 kHz and 1 x 10 kHz (left) and 1 x 10 kHz (right)
1 1 1 x 20 kHz and 1 x 10 kHz (left) and 1 x 10 kHz (right)
2 2 x 10 kHz (left) and 2 x 10 kHz (right)
2 2 x 20 kHz
Possible
number of
channels
per carrier
1 1 x 20 kHz (left) and 1 x 20 kHz (right)

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3.3 Aspects of infra-red distribution
systems
A good infra-red distribution system ensures that all
delegates in a conference venue receive the distributed
signals without disturbance. This is achieved by using
enough radiators, placed at well planned positions, so
that the conference venue is covered with uniform
Irradiation of adequate strength.
There are several aspects that influence the uniformity
and quality of the infra-red signal, which must be
considered when planning an infra-red radiation
distribution system. These are discussed in the next
sections.
3.3.1 Directional sensitivity of the
receiver
The sensitivity of a receiver is at its best when it is aimed
directly towards a radiator. The axis of maximum
sensitivity is tilted upwards at an angle of 45 degrees
(see Figure 3.2-C).
Rotating the receiver will decrease the sensitivity. For
rotations of less than +/- 45 degrees this effect is not
large, but for larger rotations the sensitivity will decrease
rapidly.
3.3.2 The footprint of the radiator
The coverage area of a radiator depends on the number
of transmitted carriers and the output power of the
radiator. The coverage area of the RA 6025 radiator is
twice as large as the coverage area of the RA 6013. The
coverage area can also be doubled by mounting two
radiators side by side. The total radiation energy of a
radiator is distributed over the transmitted carriers. When
more carriers are used, the coverage area gets
proportionally smaller.
The receiver requires a strength of the IR signal of 4
mW/m2 per carrier to work without errors (resulting in a
80 dB S/N ratio for the audio channels). The effect of the
number of carriers on the coverage area can be seen in
Figure 3.3-A and Figure 3.3-B. The radiation pattern is
the area within which the radiation intensity is at least
the minimum required signal strength.
Figure 3.3-A Total coverage area of RA 6013 & RA 6025 for 1
to 8 carriers
1
8
2
4
Figure 3.3-B Polar diagram of the radiation pattern for 1, 2, 4
& 8 carriers
The cross section of the 3-dimensional radiation pattern
with the floor of the conference venue is known as the
footprint (the white area in Figure 3.3-C to Figure 3.3-E).
This is the floor area in which the direct signal is strong
enough to ensure proper reception, when the receiver is
directed towards the radiator. As shown, the size and
position of the footprint depends on the mounting height
and angle of the radiator.

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Figure 3.3-C The radiator mounted at 15°to the ce iling
Figure 3.3-D The radiator mounted at 45°to the ceiling
Figure 3.3-E The radiator mounted perpendicular (at 90°) to
the ceiling
3.3.3 Ambient lighting
The DCS 6000 Digital IR system is practically immune
for the effect of ambient lighting. Fluorescent lamps
(with or without electronic ballast or dimming facility),
such as TL lamps or energy saving lamps give no
problems with the DCS 6000 Digital IR system. Also
sunlight and artificial lighting with incandescent or
halogen lamps up to 1000 lux give no problems with the
DCS 6000 Digital IR system.
When high levels of artificial lighting with incandescent
or halogen lamps, such as spotlights or stage lighting are
applied, you should directly point a radiator at the
receivers in order to ensure reliable transmission. For
venues containing large, unscreened windows, you must
plan on using additional radiators.
For events taking place in the open air a site test will be
required in order to determine the required amount of
radiators. With sufficient radiators installed, the receivers
will work without errors, even in bright sunlight.
3.3.4 Objects, surfaces and reflections
The presence of objects in a conference venue can
influence the distribution of infra-red light. The texture
and colour of the objects, walls and ceilings also plays an
important role.
Infra-red radiation is reflected from almost all surfaces.
As is the case with visible light, smooth, bright or shiny
surfaces reflect well. Dark or rough surfaces absorb large
proportions of the infra-red signal (see Figure 3.3-F).
With few exceptions it cannot pass through materials that
are opaque to visible light.
100% 40% 100% 80%
Figure 3.3-F The texture of the material determines how
much light is reflected and how much is
absorbed

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Problems caused by shadows from walls or furniture can
be solved by ensuring that there are sufficient radiators
and that they are well positioned, so that a strong enough
infra-red field is produced over the whole conference
area. Care should be taken not to direct radiators towards
uncovered windows, as most of this radiation will
subsequently be lost.
3.3.5 Positioning the radiators
Since infra-red radiation can reach a receiver directly
and/or via diffused reflections, it is important to take this
into account when considering the positioning of the
radiators. Though it is best if receivers pick up direct
path infra-red radiation, reflections improve the signal
reception and should therefore not be minimised.
Radiators should be positioned high enough not to be
blocked by people in the hall (see Figure 3.3-G and
Figure 3.3-H).
Figure 3.3-G Infra-red signal blocked by a person in front of
the participant
Figure 3.3-H Infra-red signal not blocked by a person in front
of the participant
The figures below illustrate how infra-red radiation can
be directed to conference participants. In Figure 3.3-I,
the participant is situated clear from obstacles and walls,
so a combination of direct and diffused radiation can be
received. Figure 3.3-J shows the signal being reflected
from a number of surfaces to the participant.
Figure 3.3-I Combination of direct and reflected radiation
Figure 3.3-J Combination of several reflected signals
For concentrically arranged conference rooms, centrally
placed, angled radiators located high up can cover the
area very efficiently. In rooms with few or no reflecting
surfaces, such as a darkened film-projection room, the
audience should be covered by direct path infra-red
radiation from radiators positioned in front.
When the direction of the receiver changes, e.g. with
varying seat arrangements, mount the radiators in the
corners of the room (see Figure 3.3-K). If the audience is

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always directed towards the radiators, you do not need
radiators at the back (see Figure 3.3-L).
If the path of the infra-red signals is partially blocked,
e.g. under balconies, you should cover the ‘shaded’ area
with an additional radiator (see Figure 3.3-M). The
figures below illustrate the positioning of the radiators:
Figure 3.3-K Radiator position for covering seats in a square
arrangement
Figure 3.3-L Radiator positioning in a conference hall with
auditorium seating and podium
Figure 3.3-M Radiator for covering seats beneath a balcony
3.3.6 Overlapping footprints and
multipath effects
When the footprints of two radiators partly overlap, the
total coverage area can be larger than the sum of the two
separate footprints. In the overlap area the signal
radiation power of two radiators are added, which
increases the area where the radiation intensity is larger
than the required intensity.
However, differences in the delays of the signals picked
up by the receiver from two or more radiators
can result in that the signals cancel each other out (multi
path effect). In worst-case situations this can lead to a
loss of reception at such positions (black spots).
Figure 3.3-N Increased coverage area caused by added
radiation power

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Figure 3.3-O Reduced coverage area caused by differences
in cable signal delay
Figure 3.3-N and Figure 3.3-O illustrate the effect of
overlapping footprints and differences in signal delays.
The lower the carrier frequency, the less susceptible the
receiver is for differences in signal delays. The signal
delays can be compensated by using the delay
compensation switches on the radiators (see section 3.5).
3.4 Planning an DCS 6000 Digital infra-
red radiation system
3.4.1 Rectangular footprints
Determining the optimal number of infra-red radiators
required to give 100% coverage of a hall can normally
only be done by performing a site test. However, a good
estimation can be made by using ‘guaranteed rectangular
footprints’.
Figure 3.4-A and Figure 3.4-B show what is meant by a
rectangular footprint. As can be seen, the rectangular
footprint is smaller than the total footprint. Note that in
Figure 3.4-B the ‘offset’ X is negative because the
radiator is actually mounted beyond the horizontal point
at which the rectangular footprint starts.
The guaranteed rectangular footprints for various number
of carriers, mounting heights and mounting angles can be
found in section 9.7. The height is the distance from the
reception plane and not from the floor.
W
H
L
X
Figure 3.4-A A typical rectangular footprint for a mounting
angle of 15°
X
W
H
L
Figure 3.4-B A typical rectangular footprint for a mounting
angle of 90°
Guaranteed rectangular footprints can also be calculated
with the footprint calculation tool (available on the
documentation CD-ROM). The given values are for one
radiator only, and therefore do not take into
consideration the beneficial effects of overlapping
footprints. The beneficial effects of reflections are also
not included. As rule of thumb can be given for systems
with up to 4 carriers, that if the receiver can pick up the
signal of two adjacent radiators the distance between
these radiators can be increased by a factor 1.4
approximately (see Figure 3.4-C).

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L
R1 R2
R3 R4
R1 R2
R3 R4
W
1.4 W
1.4 L
Figure 3.4-C The effect of overlapping footprints
3.4.2 Planning radiators
Use the following procedure to plan the radiators:
1. Follow the recommendations in section 3.3 in order
to determine the positioning of the radiators.
2. Look up (in the table) or calculate (with the
Footprint Calculation Program DIS_FCPv5.3_.xlt)
the applicable rectangular footprints.
3. Draw the rectangular footprints in the lay-out of the
room.
4. If the receiver can pick up the signal of two adjacent
radiators in some areas, determine the overlap effect
and draw the footprint enlargement(s) in the lay-out
of the room.
5. Check whether you have sufficient coverage with
the radiators at the intended positions.
6. If not so, add additional radiators to the room.
See Figure 3.3-K, Figure 3.3-L and Figure 3.3-M for
examples of a radiator lay out.
Tip: The Footprint Calculation Program DIS_FCPv5.3_.xlt
eases the work planning radiator coverage. The Program is to
be found at the ‘DCS 6000 Digital IR System User Manual
CD’
3.4.3 Cabling
Signal delay differences can occur due to differences in
the cable length from the transmitter to each radiator. In
order to minimize the risk of black spots, use equal cable
length from transmitter to radiator if possible (see Figure
3.4-D). When radiators are loop-through connected, the
cabling between each radiator and the transmitter should
be as symmetrical as possible (see Figure 3.4-E and
Figure 3.4-F). The differences in cable signal delays can
be compensated with the signal delay compensation
switches on the radiators.
50m
50m
50m
50m
Figure 3.4-D Radiators with equal cable length
Figure 3.4-E Asymmetrical arrangement of radiator cabling (to
be avoided)
Figure 3.4-F Symmetrical arrangement of radiator cabling
(recommended)

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3.5 Setting the radiator delay switches
As described in section 3.3.6, differences in the delays of
the signals picked up by the receiver from two or more
radiators can cause black spots as a result of the multi
path effect. The signals picked up by the receiver are
delayed by:
the transmission from transmitter to radiator through
the cable (cable signal delay)
the transmission from radiator to receiver through
the air (radiation signal delay)
for systems with two or more transmitters: the
transmission through the slave transmitter(s)
To compensate the signal delay differences, the delay of
each radiator can be increased. These signal delays can
be set with the delay switches at the back of the radiator.
The cable signal delays can be determined in the
following two ways:
by measuring the cable lengths
by measuring the impulse response time with a delay
measurement tool
In both cases the cable signal delays can be calculated
manually and with the delay switch calculation tool
(available on the documentation CD-ROM). It is not
necessary to calculate the cable signal delay in case:
the radiators are directly connected to the transmitter
with equal cable length;
radiators are loop-through connected, but with less
than 5 m distance between the first and last radiator
in a trunk, and with equal cable length between the
first radiator in each trunk and the transmitter.
In these cases set the delay switches on all radiators to
zero and determine whether to compensate for radiation
signal delay (see section 3.5.3).
The next sections describe how to calculate the delay
switch positions manually for systems with one
transmitter, or two or more transmitters. See the delay
switch calculation tool for the procedures how to
calculate the delay switch positions automatically.
Tip: The Delay Switch Calculation tool DIS_DSCv5.3a_.XLT
eases the calculation of the delay switch positions. The
Program is to be found at the ‘DCS 6000 Digital IR System
User Manual CD’
3.5.1 System with one transmitter
3.5.1.1 Determining delay switch
positions by measuring the
cable lengths
Use the following procedure to determine the delay
switch position based on cable lengths:
1. Look up the cable signal delay per meter of the used
cable. The manufacturer specifies this factor.
2. Measure the lengths of the cables between the
transmitter and each radiator.
3. Multiply the lengths of the cables between the
transmitter and each radiator with the cable signal
delay per meter. These are the cable signal delays
for each radiator.
4. Determine the maximum signal delay.
5. Calculate for each radiator the signal delay
difference with the maximum signal delay.
6. Divide the signal delay difference by 33. The
rounded off figure is the signal delay switch position
for that radiator.
7. Add delay switch positions for radiators under a
balcony, if applicable (see section 3.5.3).
8. Set the delay switches to the calculated switch
positions.
Caution: Turn the delay switches carefully to a new
position until you feel that it clicks into position, to
prevent that a switch is positioned between two numbers,
which would result in a wrong delay setting.
Note: For systems with a cable length difference of more
than 50 meters, it is recommended to use a measurement
tool to determine the delay differences in order to
calculate the delay switch positions.
Figure 3.5-A and Table 3.5-1 illustrate the calculation of
the cable signal delay.

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20m
20m
30m
30m
R2
R5 R4
R3
R1
20m
Figure 3.5-A System with five radiators and measured cable
lengths
Note: The used cable signal delay per meter is an
example. Use the actual signal delay per meter in this
calculation as specified by the manufacturer.
Caution: Turn the delay switches carefully to a new
position until you feel that it clicks into position, to
prevent that a switch is positioned between two numbers,
which would result in a wrong delay setting.
Table 3.5-1 Calculation of the cable signal delays
Radiator
number Total cable length [m] Cable signal delay per meter [ns/m] Cable signal delay [ns] Signal delay difference [ns] Delay switch position
1 30 5,6 30*5.6 = 168 280-168 = 112 112/33 = 3.39 = 3
2 30+20 = 50 5,6 50*5.6 = 280 280-280 = 0 0/33 = 0
3 20 5,6 20*5.6 = 112 280-112 = 168 168/33 = 5.09 = 5
4 30 5,6 30*5.6 = 168 280-168 = 112 112/33 = 3.39 = 3
5 30+20 = 50 5,6 50*5.6 = 280 280-280 = 0 0/33 = 0
3.5.1.2 Determining delay switch
positions by using a delay
measuring tool
The most accurate way to determine the cable signal
delays is to measure the actual signal delay for each
radiator as described in the following procedure:
1. Disconnect the cable from a radiator output of the
transmitter and connect this to a delay measurement
tool.
2. Disconnect a radiator from this cable.
3. Measure the impulse response time (in ns) of the
cable(s) between the transmitter and the radiator.
4. Reconnect the cable to the radiator and repeat steps
2 to 4 for the other radiators that are connected to
the same transmitter output.
5. Reconnect the cable to the transmitter and repeat
step 1 to 5 for the other radiator outputs of the
transmitter.
6. Divide the impulse response times for each radiator
by two. These are the cable signal delays for each
radiator.
7. Determine the maximum signal delay.
8. Calculate for each radiator the signal delay
difference with the maximum signal delay.
9. Divide the signal delay difference by 33. The
rounded off figure is the delay switch position for
that radiator.
10. Add delay switch positions to radiators under a
balcony, if applicable (see section 3.5.3)
Set the delay switches to the calculated delay switch
positions.

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Figure 3.5-B and Table 3.5-2 illustrate the calculation of
the signal delays and the delay switch positions.
584 ns 350 ns
563 ns 339 ns
R2
R5 R4
237 ns
R1
R3
Figure 3.5-B Calculation System with five radiators and
measured impulse response times
Note The calculated delay switch positions based on
impulse response time can differ from the calculated
delay switch positions based on cable lengths. This is
caused by the accuracy of the measurements and the
accuracy of the cable signal delay factor per meter as
specified by the manufacturer of the cable. If the impulse
response time is measured correctly, the calculated delay
switch positions will be the most accurate.
Table 3.5-2 Calculation of the delay switch positions of a system with one transmitter
Radiator
number Impulse response time [ns] Cable signal delay [ns] Signal delay difference [ns] Delay switch position
1 350 350/2 = 175 292-175 = 117 117/33 = 3.54 = 4
2 584 584/2 = 292 292-292 = 0 0/33 = 0
3 237 237/2 = 118 292-118 = 174 174/33 = 5.27 = 5
4 339 339/2 = 169 292-169 = 123 123/33 = 3.73 = 4
5 563 573/2 = 281 292-281 = 11 11/33 = 0.33 = 0
3.5.2 System with two or more
transmitters in one room
When radiators in one multi purpose room are connected
to two transmitters, an extra signal delay is added by:
Transmission from master transmitter to slave
transmitter (cable signal delay).
Transmission through the slave transmitter.
Use the following procedure to determine the delay
switch positions in a master-slave configuration:
1. Calculate the cable signal delay for each radiator,
using the procedures for a system with one
transmitter.
2. Calculate the signal delay of the cable between the
master and the slave transmitter in the same way as
for cables between a transmitter and a radiator.
3. Add to the cable signal delay of the cable between
the master and the slave, the delay of the slave
transmitter itself: 33 ns. This gives the master-to
slave signal delay.
4. Add the master-to-slave signal delay to each radiator
connected to the slave transmitter.
5. Determine the maximum signal delay.
6. Calculate for each radiator the signal delay
difference with the maximum signal delay.
7. Divide the signal delay difference by 33. The
rounded off figure is the signal delay switch position
for that radiator.
8. Add delay switch positions to radiators under a
balcony, if applicable (see section 3.5.3)
9. Set the delay switches to the calculated delay switch
positions

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Note: When a master-slave configuration is used for
rooms which are always separated, the delay switch
positions can be determined per system and the delay
caused by transmission from master to slave transmitter
can be ignored.
Caution: Turn the delay switches carefully to a new
position until you feel that it clicks into position, to
prevent that a switch is positioned between two numbers,
which would result in a wrong delay setting.
Figure 3.5-C, Table 3.5-1, Table 3.5-3 and Table 3.5-4
illustrate the calculation of the extra master-slave signal
delay.
R1
50m
R3
R4
R6
Tx2
R5
R2 Tx1
50m
50m
50m
50m
50m
50m
Figure 3.5-C System with master and slave transmitter in
multi purpose room
Table 3.5-3 Calculation of the master-to-slave signal delays
Cable length master-
slave transmitter [m] Cable signal delay per meter [ns/m] Cable signal delay [ns] Signal delay slave transmitter [ns] Master-to-slave signal delay [ns]
50 5,6 50 x 5.6 = 280 33 280 + 33 = 313
Table 3.5-4 Calculation of the delay switch positions of a system with two transmitters
Radiator
number Transmitter Master-to- slave signal Cable signal delay per meter [ns/m] Cable signal delay [ns] Signal delay difference [ns] Delay switch position
1 Master 0 168 0+168 = 168 593-168 = 425 425/33 = 12.88 = 13
2 Master 0 280 0+280 = 280 593-280 = 313 313/33 = 9.48 = 9
3 Master 0 112 0+112 = 112 593-112 = 481 481/33 = 14.58 = 15
4 Master 0 168 0+168 = 168 593-168 = 425 425/33 = 12.88 = 13
5 Master 0 280 0+280 = 280 593-280 = 313 313/33 = 9.48 = 9
6 Slave 313 168 313+168 = 481 593-481 = 112 112/33 = 3.39 = 3
7 Slave 313 280 313+280 = 593 593-593 = 0 0/33 = 0
8 Slave 313 112 313+112 = 425 593-425 = 168 168/33 = 5.09 = 5
9 Slave 313 168 313+168 = 481 593-481 = 112 112/33 = 3.39 = 3
10 Slave 313 280 313+280 = 593 593-593 = 0 0/33 = 0

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3.5.3 System with more than 4 carriers
and a radiator under a balcony
Figure 3.5-D illustrates a situation in which a radiation
signal delay occurs and which can be compensated for.
For systems with more than four carriers, add one delay
switch position per 10 meter (33 feet) difference in signal
path length to the radiators which are closest to the
overlapping coverage area. In Figure 3.5-D the signal
path length difference is 12 meter. Add one delay switch
position to the calculated switch position(s) for the
radiator(s) under the balcony.
16m 4m
Figure 3.5-D Radiation path length difference for two radiators
3.6 Testing the coverage area
An extensive reception quality test must be done to make
sure that the whole area is covered with IR radiation of
adequate strength and that there are no black spots. Such
a test can be done in two ways:
3.6.1 Testing during installation
1. Check that all radiators are connected and powered
up and that no loose cables are connected to a
radiator. Switch the transmitter off and on to re-
initialise the auto equalisation of the radiators.
2. Set the transmitter in the Test-mode (see section
4.5.7). For each channel, a different test tone
frequency will be transmitted.
3. Set a receiver on the highest available channel and
listen via the headphones to the transmitted test tone.
4. Test all positions and directions (see next
paragraph).
3.6.2 Testing during a meeting
1. Set a receiver in the Test-mode and select the
highest available carrier. The quality of the received
carrier signal is indicated on the display of the
receiver (see section 6.3).
2. Test all positions and directions (see next
paragraph). The quality indication should be
between 00 and 39 (good reception).
3.6.3 Testing all positions and
directions
With the transmitter and receiver in one of the two test
modes, go around the conference hall and test the
reception quality at every position where the infra-red
signals must be received. When an area is detected where
there is bad reception or even no reception at all, three
main causes must be considered:
3.6.4 Bad coverage
The receiver cannot pick-up infra-red radiation of
adequate strength. This can be because the tested
position is outside the footprint of the installed radiators
or the radiation is blocked by obstacles such as a column,
an overhanging balcony or other large objects.
Check that you used the correct footprints for the system
design, that radiators with enough output power are
installed and that a radiator is not accidentally switched
to half power operation. When the bad reception is
caused by a blocked radiation path, try to remove the
blocking obstacle or add an extra radiator to cover the
shaded area.
3.6.5 Black spots
The receiver picks-up IR signals from two radiators
which cancel out each other. The multipath effect can be
identified by the observation that the bad reception only
occurs along a specific line and/or when good reception
returns when the receiver is rotated to another direction.
This can be confirmed by keeping the receiver in the
position and direction with the bad reception and then
either shading-off the radiation from one radiator with
your hand or switching off one radiator. If this improves
the reception quality, then the multipath effect is causing
the problem. Note that IR radiation that is reflected from

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a surface with a high reflectabiliy can also cause
multipath problems.
Black spots can occur in case a transmitter is located in
the same room as the radiators. In that case, disable the
mini IR radiator of the transmitter with the configuration
menu (see section 2.5.16).
Check that the signal delay compensation switches on
the radiators are set to the correct value and that a switch
is not accidentally positioned between two numbers. Re-
check your system design. When necessary, reduce the
distance between the two radiators that cause the
problem and/or add an extra radiator. Note that due to the
physical characteristics of the signal distribution, it is not
always possible to completely avoid multi path effects.
3.6.6 Interference from IR systems
IR assistive hearing systems and IR microphones
operating at frequencies above 2 MHz can disturb the
reception at the lowest carriers. If such is the case,
disable the lowest two carriers (see section 4.5.11) and
re-check the reception.