Manual
Model 374A User Guide Issue 3, August 2019
Studio Technologies, Inc. Page 17
MODEL 374A
INTERCOM BELTPACK
Whenever a Model 374A audio input chan-
nel receives a call signal (20 kHz audio
tone) the orange LED on its companion talk
button will first flash and then light continu-
ally. The only exception is if button 4 has
been set to the Call mode. (In this mode
button 4 will allow call signals to be gener-
ated on talk channels 1, 2, and 3.) It will
not light in response to a call signal being
present on audio input channel 4.
By using a 20 kHz tone for call signaling
the Model 374A is compatible with legacy
intercom equipment, including the vener-
able RTS BP-325 beltpack. When intercon-
necting Model 374A and BP-325 units using
an appropriate Dante-enabled interface,
such as the Studio Technologies’ Model
45DR Intercom Interface, call signaling
is fully compatible. Compatibility with the
Clear-Com® method of call functionality
is also possible by using the Model 45DC
Intercom Interface. (It converts the DC call
signal associated with pin 3 of a Clear-Com
party-line circuit to a 20 kHz tone.) Also,
devices such as the Studio Technologies’
Model 44D Audio Interface will send and
receive 20 kHz signals that are be compat-
ible with the Model 374A. The Model 44D
responds to the state of its GPI (general-
purpose input) signals and activate 20 kHz
tones, summing them with the audio sig-
nals which are then transported “in band”
via the Dante audio paths. Audio signals re-
ceived by the Model 44D will be monitored
for the presence of 20 kHz call signals. If
call signals are detected the GPO (general-
purpose output) signals will activate.
How to Identify a Specific
Model 374A
The Dante Controller software application
offers an Identify command that can be
used to help locate a specific Model 374A.
When Identify is selected it will send a
command to a single Model 374A unit.
On that specific unit the four pushbut-
ton LEDs will light in a unique pattern. In
addition, the SYS and SYNC status LEDs,
located directly below the etherCON RJ45
receptacle on the bottom panel, will slowly
flash green. After a few seconds the LED
identification pattern will cease and normal
Model 374A button LED and Dante status
LED operation will resume.
If configured, the Identify command can
also cause the mic kill function to activate.
For details please refer to the next para-
graph of this guide.
Mic Kill Function
The Model 374A includes a mic kill func-
tion, allowing talk buttons that have been
placed in their enabled (on) state to be
remotely changed to their disabled (off)
state. This allows one or more talk chan-
nels on a specific Model 374A that have
been enabled to be remotely disabled.
The reason for this function is simple. It’s
common in intercom applications for users
to enable a talk channel and then go “off
headset,” forgetting that they’ve left the
talk channel enabled. While they take a
break or go to lunch, all other users listen-
ing to that channel may hear unwanted
audio! Having the ability to disable this
talk channel can be very useful.
A configurable choice in the STcontroller
software application is used to select
which of the mic kill methods, Device ID
or Global Kill Command, will be active.
Either or both can be enabled as desired.
It’s also possible to disable the mic kill
function.
If the Device ID method of activating
mic kill is enabled, whenever the specific