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Chapter 5: Additional Operational Information 61
3
Use the Down and Up switches to switch
between the parameter values.
4
When you have chosen your desired op-
tion, press Set.
The LED Time Code Display will return to
showing time code numbers. The USD will
retain the setting, even when the unit is
powered off and on again, until it is
changed.
MTC Idle Mute
MTC is output constantly whenever the
USD is generating time code. Optionally,
this constant output can be set to mute
when time code (LTC) is idle.
To mute idle-time MTC output from the front
panel:
1
Use the front panel Set, Up and Down
switches to display Idle MTC (IdLE 7C).
2
Press Set to display the current state (On
or Off).
3
Press Up or Down to turn Idle MTC off.
4
Press Set again to exit and return USD to
its previous state.
For USD Setup instructions for Idle MTC,
see “MTC Output and Idle Muting” on
page 51.
Managing and Selecting
Video Inputs
The USD has two independent video in-
puts, referred to as “Video In” and “Video
Ref” on USD’s rear panel. These let you use
one of the video inputs as a Clock Refer-
ence (the resolver sample clock master ref-
erence) and use the other input for working
with VITC time code and the character
generator (window dub).
Don't worry if you have just a single video
source. The USD provides a very simple
method for connecting your single video
source to both of the video inputs. See “Us-
ing Video Inputs with VITC and the Char-
acter Generator” on page 62.
In a typical video setup, you will supply a
reference video signal (black burst or color
bars) to your VCR and to the USD Video Ref
input. You will then connect the VCR's
video output to the USD Video In input. Fi-
nally, the USD Video Out will be fed to
your picture monitor and/or another VCR.
Using Video Inputs as Clock Reference
The USD lets you choose either of its video
inputs as the Clock Reference for generat-
ing system clocks. There is no performance
advantage to choosing one input over the
other. Pro Tools and USD Setup allow you
to freely select either input.
If you plan to control your USD only from
its front panel, then there is a flexibility ad-
vantage in using the Video Ref input as
your Clock Reference. This is because
there's no way to select the Video In con-
nector as the Clock Reference when using
the front panel controls. When you use the