Tektronix SPG8000 Technical Reference page 113

SDI button menu (Option SDI only)
CLEAR UDW. Use this menu item to clear the entire User Data Word. Press
the ENTER button to enter the CLEAR UDW mode, which will present the
following dialog:
Press the ENTER button to clear the User Data Word and exit CLEAR UDW, or
press the BACK button to exit without clearing the User Data Word.
CS. Use this menu item to set the Checksum. Press the ENTER button to edit
the Checksum. You can set the Checksum from 0x00 to 0xFF (in 8-bit mode),
or from 0x000 to 0x3FF (in 10-bit mode). Use the left (◄) and right (►) arrow
buttons to position the cursor, and then use the up (▲) and down (▼) arrow
buttons to set the number for that position. Press the ENTER button to confirm
the Checksum and exit Checksum editing.
Auto-Calculate CS. Use this menu item to enable or disable checksum
auto-calculation. Use the left (◄) and right (►) arrow buttons to select between
Enable or Disable, and then press the ENTER button to confirm the choice.
NOTE.
Different video modes and formats have different ranges of lines and pixels
in their active and ANC spaces. Users should be careful to change the line, field
and sample offset parameters of the ANC insertion feature after changing video
modes or formats to be sure the ANC data is programmed as desired.
If the line number or sample offset are left at values outside the allowed range for
a given format, the packet will not be inserted in the stream. Alternatively if these
parameters are left at values near the end of active or ANC space, the packet may
overwrite other elements of the stream such as EAV and SAV.
Line. Use this menu item to set the line to carry the ancillary data payload. Use
the left (◄) and right (►) arrow buttons to set the line number. This menu item is
available only in progressive formats.
Field. Use this menu item to set the Field to carry the ancillary data payload. Use
the left (◄) and right (►) arrow buttons to select between 1 Only, 2 Only, or 1
and 2. This menu item is available only in interlaced formats.
Field 1 Line: <line number>. Use this menu item to set the line in Field 1 to carry
the ancillary data payload. Use the left (◄) and right (►) arrow buttons to set the
line number. This menu item is available only in interlaced formats.
Field 2 Line: <line number>. Use this menu item to set the line in Field 2 to carry
the ancillary data payload. Use the left (◄) and right (►) arrow buttons to set the
line number. This menu item is available only in interlaced formats.
SPG8000 Technical Reference 101