Deutsche Telekom Tiptel 1020 1081520 Manuel D’Utilisation

Message waiting indicator (MWI) 

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Message waiting indicator (MWI) 

Your telephone supports different types of message waiting indicator. Apart from 
FSK (Frequency Shift Keying), the type depends on the MWI switch setting on the 
rear of the unit. Information on the MWI type used is available from your system 
administrator or network provider. 

FSK message waiting indicator 

A special, coded signal of the CLIP ID is used to show waiting messages, and is in-
terpreted irrespective of the position of the telephone's MWI switch. 

If the network provider or your telecommunication system sends an MWI signal, a 
"letter symbol" is shown on the display and the LED starts to flash. 

To disable the MWI, the relevant signal must be sent by the network operator or tel-
ecommunication system. 

MWI with polarity change of the telephone line voltage 

When the switch is set to PR1 (Polarity Reversal) or PR2, the LED lights up when 
the polarity of the telephone line voltage changes. If the LED lights up when it 
shouldn't, switch from PR1 to PR2 or vice versa. 

To disable the MWI, the telecommunication system must switch the telephone line 
voltage back to the original polarity. 

MWI using high voltage 

When the switch is set to HV (High Voltage), the LED lights when the telephone line 
voltage exceeds approx. 70V. 

To disable the MWI, the telecommunication system must change the telephone line 
voltage back to the original value.