User Guide
Configuring the Yealink EXP20 LCD Expansion Module
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If you leave this field blank, the LCD screen of the EXP20 LCD expansion module will
display the default label “DTMF”.
5. Click Confirm to accept the change.
Prefix
You can configure an Ext key as the prefix key. If you press the prefix key when the phone is idle,
the phone will enter the dialing screen and display the prefix number you specified. You can
enter other digits and then dial out.
To configure an Ext key as the prefix key:
1. Click on Dsskey->Ext Key.
2. In the desired Ext key field, select Prefix from the pull-down list of Type.
3. Enter the prefix number you want to add before the dialed number in the Value field (e.g.,
0592).
4. Enter the desired value in the Label field or leave it blank.