Natcomm
Page 19
HANG UP AFTER DIAL OUT
DS3
incorporates a HANG UP TONE DETECTOR which is designed to detect
the US specification hang up tones that will be present when
DS3
has made an
outgoing call to a programmed Cell Phone or External Number after the
completion of the call. This process is fully automatic.
When installed on PBX systems, the Hang Up tone generated may be outside
of the cadence and frequency normally used in the USA for Hang Up tones. In
this situation,
DS3
may not hang up until the Maximum Door Phone Call Time
has elapsed. The Hang Up detector, looks for:
1.
A Tone Frequency between 200Hz and 600Hz.
2.
A Tone Duration between 300mS and 600mS.
3.
A 50% Duty Cycle +/- 20%
(Ie ON and OFF periods should be the same +/- 20%)
You can adjust your PBX system to generate Hang Up tones as per the above
specification, or to output normal USA Hang Up tones.
OR
You can PRESS ANY TOUCH TONE NUMBER from (0 to 9) on your telephone
to cause an immediate disconnection of the call. Note: # and * cannot be used,
as they are used for other functions.
AND/OR
You can set the Maximum Door Phone Call Time to a time less than 99 seconds
but which is still long enough to communicate with your visitors.
DS3
will
terminate all Door Phone calls at this time setting.
ELECTRO MAGNETIC INTERFERENCE
At some sites, Electro Magnetic Interference (often caused by older poor quality
‘switch mode’ power supplies) can interfere with
DS3
’s ability to reliably detect
these tones. As a result,
DS3
may not hang up until the Maximum Door Phone
Call Time has elapsed.
Should this occur, you can overcome the problem by moving the offending ‘switch
mode’ power supply away from the
DS3
and its approved power supply. The
distance to be moved, will depend on the level of noise generated and will need to
be determined by trial and error.
