Nokia 638 Cellular Phone
(170-1211)                 Additional Features        Faxback Doc. # 45241

Sending DTMF Tones

The Dual Tone Multi Frequency (DTMF) feature allows you to send touch tones
which can be used to control equipment such as bank-by-phone or voice-mail
by using your cellular phone.

There are two alternative ways to send DTMF tones:

1.  Manual dialing

    A.  Make a call to the desired number in the usual way (e.g. to your
        bank's computer phone number).

    B.  Enter the digits to be sent as DTMF tones (e.g., your bank account
        number and password).

2.  Automatic dialing

You can send a string of digits as DTMF tones by storing the string in a
phone directory location and then recalling it for automatic DTMF trans-
mission.

  When storing the string, insert a wait character between the access phone
  number and DTMF number.  (See Adding a Wait Character below.)

  A.  Recall the phone directory location containing the phone number and
      DTMF string to be sent.

  B.  Press SEND to dial the phone number.

  C.  After the phone number has disappeared from the display, wait for the
      tone and press SEND.

      If the keypad tones have been set off, the DTMF tones will be sent,
      but you will not hear them.

  D.  To end the call, press END after the DTMF transmission is completed
      and the phone has returned to the normal call mode.

NOTE:  If you recall a DTMF number from the memory during a call, do not
       recall the number by first entering the location number and then
       pressing RCL or /\ / \/, because then the location number will be
       sent as DTMF tones.

Adding a Pause Character

If the device to which you are sending the DTMF string, needs to receive
the number slowly or after a pause, insert one or more pause characters of
2.5 seconds between the required DTMF digits.

To create a pause character 'p':

1.  Press MENU first and then #. (E.g., if you want to send your password
    as DTMF tones with a 'p' character between each digit, the string
    should be sent as 1p2p3p4.)

Adding a Wait Character

For automatic dialing, you can store the DTMF string within the same memory
location as the access phone number by storing a wait character between the
phone number and the DTMF number.

To create a wait character 'w':

1.  Press MENU first and then # twice.

To send a DTMF sequence containing a wait character, see Automatic Dialing
above.

Call Waiting

Your cellular service provider may offer a call waiting option.  This net-
work feature allows you to make or answer a second call while you already
have a call in progress.

To make a call while you have a call in progress:

1.  Enter the phone number or recall the number from the memory and press
    SEND.

To answer an incoming call while you have a call in progress:

1.  Press SEND at an incoming call alert.

Note:  The Call Waiting network feature normally needs to be specifically
       subscribed to and may not be available in all cellular service
       provider networks.  Contact your local cellular service provider
       for more information.

Activating PIN Calls

Note:  This feature may not be available on all networks, check with your
       local service providers.

This function allows you to activate or deactivate a PIN call.  When this
function is set to on, a PIN code is requested at call setup.

To activate the PIN call:

1.  Enter the control code * # 7 pqrs 4 ghi 6 mno 2 abc 5 jkl 5jkl #
    (spells * # PIN CALL #).

    The phone asks for your four-digit PIN CODE?.

2.  Enter your PIN code and press STO.

    The message PIN CALL ON is briefly displayed confirming the PIN call
    activation.

To deactivate the PIN call:

1.  Enter the control code * # 7 pqrs 4 ghi 6 mno 2 abc 5 jkl 5 jkl #
    (spells * # PIN CALL #).

    The phone asks for your four-digit PIN CODE?.

2.  Press STO without entering the PIN code.

    The message PIN CALL OFF is briefly displayed confirming the PIN call
    deactivation.

To make a call when the PIN call is set to on:

1.  Make the call in the usual way.

    The message PIN CALL is displayed.  The phone asks you to wait for a
    tone (WAIT FOR A PROMPT).

2.  After the tone, press SEND.

    The message SENDING PIN is displayed.  If the message remains on the
    display, press SEND to resend the PIN code.

Note:  When the phone is set to PIN CALL ON, an emergency call to the
       emergency number programmed into your phone (e.g., 911 or another
       official emergency number) will be dialed as a normal call without
       the PIN code request.


(LB/EB 11/5/97)