Datasheet

Studio Technologies, Inc. Live-Link Jr. Remote Camera Interface System, Issue 5, Page 2
Intercom
A major strength of Live-Link Jr. is its integrated 2-channel
intercom system. With its extensive resources and capabilities
the typical hassles and limitations associated with intercom
system implementation should be a thing of the past. A 2-
channel party-line intercom interface is provided on both the
camera end and truck end units. This allows user beltpacks,
such as the ubiquitous RTS® BP325, to be directly connected
and powered. A fully functional camera-end-to-truck-end
“comms” system can be up and running in just minutes. The
advanced 2-wire-to-4-wire converter circuitry provides simply
excellent audio performance. Adjustment of the converter’s
“nulling” is user activated by pushbutton switches on both the
camera end and truck end units. The pushbuttons allow both
the local and alternate-end nulling process to be started.
The Live-Link Jr. truck end also provides a 4-wire interface
that is associated with intercom channel 2. An audio input
and audio output allows direct interfacing with local and
remotely-located matrix intercom systems. In this manner
intercom users at the camera end unit, truck end unit, and
remote locations can be part of the same intercom circuit.
The party-line interface on the camera end unit provides
a power source and the required signal terminations. This
allows direct connection of user beltpacks; a typical applica
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tion could use up to three BP325 units. With its selectable
operating mode the truck end party-line interface offers
additional resources. Most applications will have the truck
end configured for stand-alone operation where power
and signal terminations are required. In this mode up to five
BP325 beltpacks could be connected. Alternately, the truck
end’s power source and signal terminations can be disabled
allowing interfacing with an existing party-line intercom
system. This will allow the truck end’s party-line interface to
become just another “user” on an already installed system.
Line/IFB Signals
Two line-level audio signals can be transported from the
truck end to the camera end. The balanced line/IFB inputs
are located on the back panel of the truck end and allow con
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nection of a variety of analog audio signals. In most applica
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tions the signals will be used for talent cueing. But the audio
quality is such that even transporting on-air signals would
be appropriate. For flexibility both line-level and “wet” IFB
(power and audio) outputs are provided on the camera end
unit. Listen-only beltpacks, such as from Studio Technolo
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gies, can be directly connected and powered by the camera
end unit’s IFB output. For flexibility the signal connected
to the line/IFB 1 input on the truck end can also be routed
to intercom channel 1. This useful feature allows intercom
users, typically camera operators, to monitor the cueing audio
signals being sent to the on-air talent.
RS-422 Data
A full-duplex RS-422 asynchronous data path links the
truck end unit to the camera end unit. This general-purpose
“serial” port can be a valuable resource when used to interface
a camera control unit located at the truck end with a camera
connected to Live-Link Jr.’s camera end unit. A current-
limited source of 5.5 volt DC power is also provided at both the
truck end and camera end units. This auxiliary power source
is specifically provided should low-cost RS-422-to-RS-232
or RS-422-to-RS-485 converters be required for specific data
transport applications.
GPI/GPO
Live-Link Jr. allows one contact closure to be transported in
each direction. The GPI (general purpose input) on the truck
end unit will correspond with the GPO (general purpose out
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put) contact closure on the camera end unit, and vice versa.
This functionality is often useful to support camera tally
Live-Link Jr. Truck End Unit Front Panel
Live-Link Jr. Truck End Unit Back Panel