Polycom Vortex EF2241, Application Note

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O
UTPUT OF
V
IEW
S
TATION CODEC TO
I
NPUT OF
V
ORTEX
D
EVICE
Connect the Positive conductor of the Vortex device to the Tip of the RCA connector and the Negative
conductor of the Vortex device to Shield of the RCA connector.
The shield of the cable is not connected.
T
IPS FOR
V
IEW
S
TATION
128 / H.323 / MP / 512
1. The volume control for the ViewStation codec controls the incoming far side audio and the local
tone generator. It does not, however, control the sound effects inside the units such as incoming
call ring and the female speech that occurs when you dial a number. This is important to note
because if the volume control is very low, it may appear that the codec audio is operating correctly
because the sound effects are still generated and will be heard in the local room. However, when
a call is connected, the local side may not hear the far side because the local volume control is too
low. Since the local participants heard the sound effects audio at a normal level, it may not be
obvious that the volume control is set too low.
The sound effects volume control can be adjusted in the S
YSTEM
I
NFO
, A
DMIN
S
ETUP
, P
HONE
A
UDIO
page.
2. If the ViewStation codec is turned off either through the power switch or unplugged from the wall
while the codec is still connected to the Vortex device via the input and output audio cables, a
loopback will occur in the codec. This means that a portion of the audio signal that is sent to the
codec from the Vortex device will be coupled into the signal that is sent from the codec to the
Vortex device. This will cause the local room to hear a reinforced version of their own speech via
the local room loudspeakers. Our recommendation is to leave the codec power on all the time;
however, if the codec must be powered down, we recommend muting either the output channel of
the Vortex device that will feed the input of the codec or the input channel of the Vortex device that
is connected to the output of the codec.
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