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TRML R
C
EMOTE
ONTROL
L
ine Impedance
When several rem
ote control units are connected in parallel on one line, the total system impedance for that line
will decrease to a point where operation is degraded. This occurs when 3 or more remotes are connected in
parallel to the line. Up to ten remotes may be connected in parallel on the same Line. The maximum loss betwee
any remote and termination panel must not exceed 20dB.
T
o compensate for this effect, the TRML remote provides dip switch selectable line impedance settings. Two wire
operation provides 600 ohm or 2.4K ohm impedance. Four wire operation provides 600 ohm or 2.4K ohm
impedance on the Tx pair and 600 ohm or 10K ohm impedance on the Rx pair. Line impedance settings ar
configured via the S1 and S2 dip switch packages located on the middle board (see Table 2 - S1, S2).
In
parallel remote installations using the same phone line for two wire operation, dip switch S1-5 should be in the
OFF position (2.4K ohms) in all remotes except the last one in the chain on Line 1, S1-6 should be in the OFF
position for Line 2, S1-7 should be in the OFF position for Line 3, S1-8 should be in the OFF position for Line 4.
In
parallel remote installation using the same phone line for four wire operation, dip switch S1-1 should be in the
OFF position (10K ohms) in all remotes except the last one in the chain on Line 1, S1-2 should be in the OFF
position for Line 2, S1-3 should be in the OFF position for Line 3, S1-4 should be in the OFF position for Line 4
the Rx pairs. Dip switch S1-5 should be in the OFF position (2.4K ohms) in all remotes except the last one in the
chain on Line 1, S1-6 should be in the OFF position for Line 2, S1-7 should be in the OFF position for Line 3, S1-8
should be in the OFF position for Line 4 for the Tx pairs.
C
rossmute
The crossmu
te feature allows the remote to mute the speaker during PTT from a parallel remote to prevent audio
feedback. Crossmute is ideal when multiple remotes are installed in close proximity that audio feedback occurs on
parallel remote speakers. No additional wires between remotes are needed to activate the crossmute feature. The
crossmute feature works by decoding the PTT control tones when parallel remotes key and mutes the speaker
cutting off the audio path to feedback through. Intercom has no effect and will be heard on parallel remotes.
T
he crossmute feature is enabled when shipped from the factory. Configuring the crossmute feature is dip switch
selectable with dip switch 6 located on the bottom of the unit (Table 1 - S1-6). "On" enables crossmute, "Off"
disables crossmute. Note: speaker becomes active all the time regardless of the handset in the off hook posit
when crossmute is disabled.
L
evel Settings
Typical level sett
ings require only a small flathead screwdriver for adjustments and a standard phillips head
screwdriver to remove the screws securing the top half of the housing to access most of the adjustments. So
adjustments can be accessed from the bottom of the remote.
T
he following adjustments assume the termination panel has been properly installed and the phone line meets
above requirements.
M
icrophone Sensitivity
R75 controls the micropho
control. The potentiometer has been factory set to provide adequate compression for normal voice audio with a
relatively quiet background noise level. Adjustment is located on the bottom baseboard and is also accessible fro
the bottom of the remote. Note: adjustment will affect transmit audio on all lines.
E
arpiece Adjust
R96 controls the R
x audio into the earpiece. The potentiometer has been factory set to provide a comfortable
earpiece level for most environments. Adjustment is located on the bottom baseboard and is also accessible fr
the bottom of the remote. Note: adjustment will affect receive audio over the earpiece of all lines.
R
x Audio Line Input
The receive line input a
djusts the audio level to the input of the compression amplifier circuitry. This allows the
threshold of compression to be adjusted from -24dBm to +15dBm. Separate compression amplifiers and
adjustments are used for each line.
10
C
ONSOLE
ne audio level into the transmit compression circuits and therefore acts as a sensitivity
n
e
for
ion
me
m
om
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