Setting Radiator Delay Switches; System With One Transmitter - Danish Interpretation Systems DCS 6000 User Manual

DIS
As described in section 3.3.6, differences in the
3.5

Setting radiator delay switches

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
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

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).
16
from transmitter
through the slave
User Manual DCS 6000 Digital IR System rev H.docx
The next sections describe how to calculate the
delay switch positions manually for systems
with one
transmitters. See the delay switch calculation
tool for the procedures how to calculate the
delay switch positions automatically.
to
Tip: The
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
Use the following procedure to determine the
cable lengths
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.
transmitter, or two
Delay Switch Calculation
User Manual
or more
tool