Yealink SIP-T21 E2 Administrator's Guide

Administrator’s Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
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dark environments. Backlight time specifies the delay time to change the intensity of the LCD
screen when the IP phone is inactive. Backlight turns off quickly if a short backlight time is
configured, this may not give users enough time to read messages. Backlight time is applicable
to SIP-
T54S/T52S/T48G/T48S/T46G/T46S/T42G/T42S/T41P/T41S/T40P/T40G/T29G/T27P/T27G/T23P/T
23G/T21(P) E2/CP860/CP920 IP phones, EXP40 (connected to SIP-T48G/T48S/T46G/T46S IP
phones) and EXP20 (connected to SIP-T29G/T27P/T27G IP phones).
You can configure the backlight time as one of the following types:
 Always Off: Backlight is turned off permanently (not applicable to SIP-
T54S/T52S/T48G/T48S/T46G/T46S/T29G IP phones).
 Always On: Backlight is turned on permanently.
 15s, 30s, 1min, 2min, 5min, 10min or 30min: Backlight is turned off when the IP
phone is inactive after a preset period of time (in seconds), but it is automatically
turned on if the status of the IP phone changes or any key is pressed.
Active Backlight Level is used to adjust the backlight intensity of the LCD screen when the
phone is active. Unused BackLight is used to adjust the backlight intensity of the LCD screen
when the phone is inactive. Active Backlight Level is applicable to SIP-T54S/T52S IP phones and
the connected EXP50, SIP-T48G/T48S/T46G/T46S IP phones and the connected EXP40, SIP-
T29G/T27P/T27G IP phones and the connected EXP20. Unused BackLight is only applicable to
SIP-T54S/T52S IP phones, SIP-T48G/T48S/T46G/T46S IP phones and the connected EXP40, SIP-
T29G IP phones and the connected EXP20.
Note
The following table lists available methods and configuration options to configure the backlight
of phone models/expansion modules.
Phone Model (and
the connected
expansion module)
Configuration
Methods
Configuration Options
T54S/T52S(EXP50)
T48G/S(EXP40)
T46G/S(EXP40)
T29G(EXP20)
Configuration Files
Web User Interface
Phone User
Interface
Unused BackLight/Inactive
Level (not applicable to
EXP50)
Active Backlight Level/Active
Level
Backlight Time (not
applicable to EXP50)
T27P/G(EXP20)
Configuration Files
Web User Interface
Active Backlight Level/Active
Level
It is not applicable to SIP-T19(P) E2 IP phones.
Before you adjust the LCD’s backlight of expansion module, make sure the expansion module
has been connected to the IP phone.

Yealink SIP-T21 E2 Specifications

General

Brand	Yealink
Model	SIP-T21 E2
Category	IP Phone
Language	English