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01-0868-401B 12/02
Tiernan VBI Data Transmission
10. Set the type of Teletext standard to be decoded, either the DVB standard or a
vendor’s proprietary standard. Issue the front panel command
VBI>Teletext>Standard=type
or the remote
VBI TELETEXT STANDARD TYPE
command.
11. To specify a particular PID within the selected service that contains Teletext
data. Issue the front panel command
VBI>Teletext>PID=PID number
or
the remote
VBI TELETEXT PID NUMBER
command.
ATSC Closed Captions
Tiernan encoders and decoders support industry-standard ATSC EIA-608 closed
captions. On the encoder side, the data found on line 21 is stripped out, placed in
the picture header, encoded and transmitted. At the decoder end, the data is
processed and re-inserted on line 21 for proper broadcasting.
ATSC closed captions are supported on a composite analog NTSC format video
signal.
Operational Considerations
Ensure that VBI teletext is
disabled
when closed captions are enabled, as teletext
overwrites all other VBI data.
Hardware Requirements
■
Encoders require a TVIP-6025 module.
■
The TDR60 decoder processes ATSC closed captions.
End-to-End Configuration
To configure the encoder and decoder for ATSC closed captioning, follow these
steps:
Encoder
1. Ensure that Teletext is disabled. Issue the front panel command
Config>Service #>VBI>Teletext>Enable=off
or the remote
TT ENABLE OFF
command.
2. Ensure that closed caption VBI data is included in the selected service video
input signal.
3. Enable the encoder for ATSC closed captions. Issue the front panel
Config>
Service #>VBI>CC=On
or the remote
VE ATSC_CC ON
command.
Decoder
4. Ensure that Teletext mode is set to off. Issue the front panel command
VBI>Teletext>Mode=Off
or the remote
VBI TELETEXT MODE OFF
command.
5. For ATSC VBI to be included in the output stream, the TDR60 requires you
to manually set the type of VBI data to decode
a.
Set the decoder VBI format control to manual. Issue the front panel
command
VBI>Format>VBI Format Cntrl=Manual
or the remote
VBI CONTROL MANUAL
command.
b. Set the VBI format to ATSC closed captions. Issue the front panel
command
VBI>Format>VBI Format=ATSCCC
or the remote
VBI FORMAT ATSCCC
command.
