Studio Technologies 5152 V.3 - Manual (Page 18)

Issue 2, June 2013 Model 5152 User Guide
Page 18 Studio Technologies, Inc.
Model 5152
Video Generator/Audio Embedder Module
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
Whenever a valid SDI signal is connected
to the selected Model 5152 input it will im-
mediately be routed to the coaxial (BNC)
and, if present, optical SDI outputs. The
situation is a little different when a valid
signal that’s connected to the SDI input is
removed. When the Model 5152 detects
that an SDI input signal is no longer pres-
ent the SDI output switches to an image
with a solid-gray color. This color remains
for approximately seven seconds as a be-
nign warning 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 5152’s output can be ter-
minated without alerting viewers that any-
thing is amiss. This gray image can also be
helpful as a marker when editing recorded
video. After the seven-second interval has
elapsed the internal generator will output
either the “720” or “1080” stored image.
It’s important to note that the Model 5152
does not perform a smooth transition when
switching between an external SDI source
and the internal SDI generator. The same
holds true when the internal color or image
generator is active and then a valid source
is connected to the SDI input. The SDI
output does not stay “locked” during the
transition as the circuitry in the Model 5152
was not designed to that level of sophisti-
cation. This shouldn’t cause an operational
issue as the Model 5152 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 consider-
ably shorter.
Output Format and Rate
When a valid signal is connected to the
SDI input it will be routed to the SDI out-
put at the identical format and rate of the
source. When the SDI input is no longer
present the internally-generated signal
will become active and be routed to the
SDI output. The format and rate of the
internally-generated SDI signal will depend
on parameters that are stored within the
Model 5152. Whether these parameters
can change depends on the configuration
of the module’s SDI output image format/
rate mode. Typically, the mode will be set
for Auto Select which allows the Model
5152 to revise its parameters by following
the format and rate of a connected SDI
signal. This ensures that the Model 5152
can generate an SDI signal that matches
the requirements of a facility or event. For
the module to “learn” a new format and
rate simply requires the momentary con-
nection of an SDI signal that has the de-
sired format and rate. As long as the signal
is present on the SDI input for a minimum
of five seconds the Model 5152 will store
the “new” format and rate parameters in
nonvolatile memory. The module will then
use those parameters whenever the in-
ternal generator is active. The only caveat
for the module to “learn” a new format/rate
combination is that it must be a compatible
combination. Refer to the Specifications
section of this guide for a complete list.
There are some applications that will bene-
fit from the internally-generated SDI output
signal always having a specific format and
rate. In this case the SDI output image
format/rate mode can be set for Locked.