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DTMF overdialling
DTMF (dual tone multiple frequency) is the tone-based
system used in the worlds telephone networks. If your
system has access to the public switched telephone network
or other networks that make use of DTMF tones, your radio
can make a call to a telephone or send control codes to a
remote device.
If you simply wish to call a PABX or PSTN number, follow
the instructions for making such calls on page 33. If,
however, once you have set up such a call you wish to send
control codes (e.g. telebanking), use DTMF overdialling.
You can only use DTMF overdialling in trunked mode.
If you wish to dial tones A to D, your radio may be pro-
grammed so that you can use the PTT key as a shift key in
conjunction with the numeric keys as follows:
n
PTT +
= A
n
PTT +
= B
n
PTT +
= C
n
PTT +
= D
So pressing the PTT key, holding it, then pressing the
key enters tone A in the DTMF string.
You can also send a pause by pressing the PTT, holding it,
and then pressing the
key. A hyphen will be entered in
the display to indicate a pause.
To use DTMF overdialling while the radio is operating on a
trunking network, first set up a call to the device you want
to send control codes to, which is usually a PABX extension
or PSTN number.
Once the call is connected:
n
Give a short press of the DTMF key ( ). The message
DTMF
and the DTMF overdialling symbol ( ) will
appear in the display.