Yealink SIP-T54S Administrator's Manual page 709

Configuring Advanced Features
Parameters Permitted Values Default
X=1-6, 9, 13 (for CP860/CP920)
For ext keys:
For SIP-T54S/T52S:
X ranges from 1 to 3, Y ranges from 1 to 60.
For SIP-T48G/T48S/T46G/T46S:
X ranges from 1 to 6, Y ranges from 1 to 40.
For SIP-T29G/T27P/T27G:
X ranges from 1 to 6, Y ranges from 1 to 20, 22 to 40 (Ext key 21 cannot be configured).
Example:
linekey.2.value = 224.5.6.20:10008
Note: The valid multicast IP addresses range from 224.0.0.0 to 239.255.255.255.
Web User Interface:
Dsskey->Line Key/Programable Key->Value
Phone User Interface:
Menu->Features->DSS Keys->Line Key X->Value
linekey.X.label/
String within 99
programablekey.X.label/ Blank
characters
expansion_module.X.key.Y.label
Description:
(Optional.) Configures the label displayed on the LCD screen for each DSS key.
For line keys:
X ranges from 1 to 29 (for SIP-T48G/S)
X ranges from 1 to 27 (for SIP-T54S/T46G/T46S/T29G)
X ranges from 1 to 15 (for SIP-T42G/T42S/T41P/T41S)
X ranges from 1 to 21 (for SIP-T52S/T27G)
X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G)
X ranges from 1 to 2 (for SIP-T21(P) E2)
For programable keys:
X ranges from 1 to 4.
For ext keys:
For SIP-T54S/T52S:
X ranges from 1 to 3, Y ranges from 1 to 60.
For SIP-T48G/T48S/T46G/T46S:
X ranges from 1 to 6, Y ranges from 1 to 40.
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