Manual

Issue 2, July 2021 Model 5401A User Guide
Page 22 Studio Technologies, Inc.
is the sample rate desired for the sine wave
audio channels provided by the tone gen-
erator function. In most applications this will
be 48 kHz. It’s possible that in some audio-
only applications 96 kHz or even 192 kHz
will be selected. Once the desired sample
rate has been selected and/or confirmed,
an external word clock source of the same
rate should be connected. If the available
external word clock source has a rate differ-
ent than the current Dante sample rate then
a review of the entire application must be
performed and a common rate selected.
If Video is selected for the sync input type
then a wide range of bi- and tri-level video
reference signals can be connected to the
sync input BNC jack. The Model 5401A’s
circuitry will automatically decode many of
the most common format/rate combinations.
These include ubiquitous “black burst” sig-
nals as well as signals intended to support
4K video applications. Refer to Appendix A
at the end of this guide for a detailed list of
compatible video sources.
If 10 MHz is selected then the sync input is
expecting connection of a sinusoidal source
of 10 MHz. A signal of this type is typically
associated with industrial or instrumentation
applications. It may also be provided by a
GPS (satellite) receiver.
If a choice of sync sources is available for a
specific application it’s recommended that
a source of word clock be utilized. This is
not because a word clock source is inher-
ently better, but rather the recommendation
is related to the Model 5401A’s circuit de-
sign. The unit’s logic circuitry has to per-
form the least amount of processing with a
word clock input signal as compared to that
required to utilize a video reference or a 10
MHz signal. All compatible signals will work
well but using a source of word clock re-
quires the least logic “horsepower.”
Termination: This is a configurable field
with two choices: Off and On.
If desired, the Model 5401A can apply a
terminating impedance to the sync input
connection. The need for an input source
to be terminated, or not, will depend on the
source of the external sync signal. Typically,
a source of sync should have one (and only
one) termination applied. A timing reference
source can generally be shared (“bused”) to
multiple devices with only the last connec-
tion on the “string” having an appropriate
termination.
If the sync input termination is configured
for Off then the sync input’s impedance will
be considered “high Z.” If the sync input
termination is selected to On and the sync
input type is selected for Word Clock or
Video the termination impedance will be 75
ohms. If 10 MHz has been selected as the
sync input type then a termination imped-
ance of 50 ohms will be applied.
These termination values were selected to
meet the technical requirements of indus-
try-standard reference signals. Word clock
should be a square wave with a source
impedance of 75 ohms. Video is typically a
complex analog signal with a source imped-
ance of 75 ohms. And a 10 MHz reference
is a normally a sine wave with a source
impedance of 50 ohms.
Submit: A Submit button is located on the
bottom of the Sync Input menu webpage.
To save any changes made to fields on the
Sync Input webpage requires that the Sub-
mit button be pressed. The Model 5401A
will immediately incorporate operating
changes as soon as the Submit button has
been pressed.
Tone Generator Menu
The Model 5401A’s tone generator function
is capable of creating eight precision sine