GUIDE TO INSTALLATION AND OPERATION
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| LGK-3901/DSK-3901
4.12 Closed Captions
Closed caption information is usually passed through the LGK-3901/DSK-3901 whatever the Closed Caption option is
set to. The reason that the option exists is that when the standard is set as NTSC (525), closed caption information is
found within the active picture (lines 20/21), and so it will be destroyed when graphics are keyed over these lines.
When this option is enabled via the SETUP > MISCELLANEOUS > CLOSED CAP front panel menu, the LGK-
3901/DSK-3901 ensures that the close caption information is preserved regardless of keyed graphics being present
on lines 20/21. Disabling the option instructs the keyers/mixers to treat these lines as part of the active picture so that
they may be keyed over.
On HD and 3G standards, close caption is contained in vertical ancillary data (VANC) on line 9, which is outside the
active picture. Since this is never processed by the keyers the close caption information is preserved whatever the
option selected.
4.13 Timecode
The following timecodes are supported by LGK-3901/DSK-3901:
•
Linear (or Longitudinal) Timecode (LTC)
o
Received via the 44-pin Terminal Block Adaptor (see sections 5.5 and 5.4.10)
o
Supports
Dropframe
and Non-Dropframe
o
Supports Forward and Backward directions
•
Vertical Interval Timecode (VITC)
o
Received via the external reference
o
Supports
Dropframe
and Non-Dropframe
When physically connected and activated, the LTC or VITC timecode source is used to adjust the internal LGK-
3901/DSK-3901 clock once per minute. When a timecode source is not connected an NTP server may be used to
periodically update the system clock. Alternatively the internal clock will free run.
Timecode source, timecode status and clock time may be viewed via the SETUP > TIMECODE front panel menu.
USO
RESTRITO
