Studio Technologies 5154 - Manual (Page 21)

Model 5154 User Guide Issue 3, September 2013
Studio Technologies, Inc. Page 21
Model 5154
Video Generator/Audio De-Embedder Module
From the factory two images are pre-load-
ed. The two are quite different from one
another with each having a unique photo
background and overlaid text. The overlaid
text provides support details on how alter-
nate custom images can be created.
It’s expected that these pre-loaded images
will be replaced with application-specific
images. They can be easily created and
what they consist of is limited only by one’s
imagination. Refer to the Technical Notes
section of this guide for details.
Transitions between External
and Internal SDI Signals
This paragraph applies when the Model
5154 has been configured for normal SDI
input mode. Whenever a valid SDI signal
is connected to the selected Model 5154
input it will immediately be routed to the
coaxial (BNC) and, if present, optical SDI
outputs. The situation is a little different
when a valid signal that’s been connected
to the selected SDI input is subsequently
removed. When the Model 5154 detects
that an SDI input signal is no longer pres-
ent the SDI output may switch to an im-
age with a solid-gray color. Depending on
the module’s configuration this color may
remain active for up to seven seconds. This
solid-gray image provides a benign warn-
ing to users that the normal SDI source
is no longer present.
During this time period it’s expected that
any on-air use of the Model 5154’s output
can be terminated without alerting viewers
that anything is amiss. This solid-gray im-
age can also be helpful as a marker when
editing recorded video. After the configured
interval has elapsed the internal generator
will output either the “720” or “1080” stored
image.
It’s also possible that the Model 5154 has
been configured to not output the solid-
gray video signal. In this case, when the
module detects that an SDI signal is no
longer present on the SDI input, the SDI
output will directly switch to the stored
image.
It’s important to note that the Model 5154
does not perform a smooth transition when
switching between an external SDI source
and the internally-generated video signals.
The same holds true when the internal
color or image generator is active and then
a valid source is connected to the selected
SDI input. The SDI output does not stay
“locked” during the transition as the circuit-
ry in the Model 5154 was not designed to
that level of sophistication. This shouldn’t
cause an operational issue as the Model
5154 was not designed to be “on air”
during those transitions; the changeover
process is not seamless by design. One
can assume that up to two seconds of
interruption will occur during transitions
but typically it will be considerably shorter.
Full-Time Video Generation
A configuration selection allows the Model
5154 to act as a full-time video generator.
In this case the selected SDI input will only
be used as an external timing reference.
The front-panel SDI Input LED will light
whenever a valid signal is connected to
the selected SDI input. But the SDI input
source will only serve as a timing refer-
ence. Its video and related data (e.g., em-
bedded audio) will not pass through to the
SDI output(s). The stored video image will
always be present on the SDI output(s).