Studio Technologies 45DR - Manual (Page 8)

Issue 2, January 2015 Model 45DR User Guide
Page 8 Studio Technologies, Inc.
performance; its ability to deliver power
while maintaining audio quality is simply
unmatched.
Audio Meters
The Model 45DR contains two sets of
5-segment LED level meters. Each set of
two meters displays the level of the signals
being sent to and received from a party-line
interface channel. At the time of installa-
tion and setup the meters are invaluable in
helping to confirm correct operation. Dur-
ing normal operation the meters offer rapid
confirmation of audio signals flowing in to
and out of the unit. Additional LED indica-
tors are also provided on the front panel,
offering a status indication of the party-line
DC power source, party-line activity status,
and the auto null functions. Two other LEDs
offer a direct indication of what source is
powering the Model 45DR.
Call Light Support
RTS TW-compatible party-line intercom
user devices, such as the BP-325, provide
a call light function using a 20 kHz square-
wave signal that is added to the designated
audio path. To achieve optimal audio per-
formance this signal, along with essentially
all content above 10 kHz, is normally re-
moved from the audio signal that is sent
out the Model 45DR’s Dante transmit audio
path. It’s also removed from the audio sig-
nal that arrives by way of the Model 45DR’s
Dante receive audio path. While the result
is excellent party-line talk audio, 20 kHz
call light signals are prevented from being
directly sent to and received from multiple
Model 45DR units. A Model 45DR feature
overcomes this limitation, detecting the call
light activity and re-generating it (again as
a 20 kHz tone) in the applicable audio path.
This allows reliable “end-to-end” call light
support between two Model 45DR units.
It also allows a Model 45DR to send and
receive call light status with an intercon-
nected Model 45DC Dante to Dual Party-
Line Interface. The Model 45DC is typically
used with Clear-Com party-line user belt-
packs including the popular RS-501 and
RS-701.
Ethernet Data, PoE, and DC
Power Source
The Model 45DR connects to a data
network using a standard 100 Mb/s
twisted-pair Ethernet interface. The physi-
cal interconnection is made by way of a
Neutrik® etherCON RJ45 connector. While
compatible with standard RJ45 plugs,
etherCON allows a ruggedized and lock-
ing interconnection for harsh or high-
reliability environments. The Model 45DR’s
operating power can be provided by way
of the Ethernet interface using the Power-
over-Ethernet (PoE) standard. This allows
fast and efficient interconnection with the
associated data network. To support PoE
power management, the Model 45DR’s
PoE interface reports to the power sourc-
ing equipment (PSE) that it is a class 3
(medium power) device. The unit can also
be powered using an external source of
12 volts DC.
For redundancy, both power sources can
be connected simultaneously. An internal
switch-mode power supply ensures that
all Model 45DR features, including party-
line intercom circuit power, are available
when the unit is powered by either source.
Four LEDs on the back panel display the
status of the network connection, Dante
interface, and PoE power source.