Televic Aladdin, Инструкция по установке и эксплуатации

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Aladdin Digital Infrared Language Distribution Installation and User Manual
Televic Conference Systems 2011-09-01 45
3.6. Setting the Radiator
Delay Switches
As described in section 1.3.6, signals picked up by
the receiver from two or more radiators can cause
black spots due to delay differences.
Signal delays reasons:

Cable signal delay, caused by the cable
transporting the signal from the transmitter to
the radiator.

Radiation signal delay, caused by the air
transporting the signal from the radiator to the
receiver.

Transmitter signal delay, caused if two or more
transmitters are used in a Bypass configuration.
To compensate the signal delay differences, the
delay of each radiator can be increased. Signal
delays can be set with the delay switch situated at
the side of the radiator. Aladdin T8 transmitter has
a digital display showing the current compensation
value. The switch can be adjusted from “00” (“00”
means no compensation) to “99”. Compensation
time is calculated by multiplying 25 ns with the
switch set value. Thus compensation time varies
between 25ns and 2475 ns.
In most cases the cable signal delays can be
calculated manually using in addition the delay
switch calculation tool (available on the
documentation CD-ROM).
How to calculate the delay switch positions
manually for systems with one, two or more
transmitters will be described in the next sections.
Refer to the delay switch calculation tool for
information how to get a computed value for the
delay switch position.
3.6.1. System with One
Transmitter
There are no cable signal delays in systems with
only one transmitter and radiators directly
connected to the transmitter with cables of
identical length. The delay switches on all radiators
are to be set to zero.
Subsequently check whether to compensate for
radiation signal delay (see section 3.6.3).
If the cable lengths differ from radiator to radiator,
the delay switch parameter can be calculated with
the formula:

Take signal delay rate as 5.6 ns/m (value as
example for calculation only, real value
depends on the cable type used)

X : delay compensation parameter, displayed
on the LCD

L
MAX
: maximum cable length in the considered
chain. For the most distanced radiator, L
MAX
and
L are identical.

L : cable length between transmitter and
radiator
Use the following procedure to determine the delay
switch position based on cable lengths:
1
．
Measure the cable length L between the
transmitter and every single radiator;
2
．
Determine the maximum cable length L
MAX
;
3
．
For each radiator calculate the cable length
difference value L
MAX
- L;
4
．
To obtain the cable signal delays for each
radiator; multiply the cable length difference of
each radiator with the cable signal delay per
meter;