The SMPTE-352 Link Number refers to a value present in the SDI output of a 4K UHD quad 3G-SDI output. There are four outputs, and each of these outputs can have an associated link number so that the connected device (our AVP HEVC Encoder in this case) can work out what 3G-SDI has been connected to which spigot on the HEVC Card.

If the SMPTE-352 Link Numbers are present (and this only seems to be available in 2SI mode, not in square division (quad) mode) then the AVP can correctly de-interleave the content regardless of the order that the inputs were presented.

You can view the link numbers (if present) by connecting to the AVP host card via SSH:

  SSH <jpaddress>
  
  login:
  
  root
  viper

Once logged in, telnet to the card in the correct slot (slot 1 to 6) in the case of the HEVC card it's normally slot 1 (if it's a single card)

  telnet slot1
  
  login:
  
  root
  (no password)