Natcomm
Page 13
HANG UP AFTER DIAL OUT
DS4 incorporates a HANG UP TONE DETECTOR which is designed to detect
‘AUSTRALIAN’ specification hang up tones that will be present at the completion of a
Door Phone call. This process is fully automatic. Some PBX systems may generate
tones outside of the cadence and frequency normally used in the AUSTRALIAN for
Hang Up tones. In this situation, DS4 may not hang up until the Maximum Door Phone
Call Time has elapsed. Our Hang Up detector, looks for:
1.
A Tone Frequency between 200Hz and 600Hz.
2.
Tone Duration between 300mS and 600mS.
3.
A 50% Duty Cycle +/- 20%
(ON and OFF periods should be the same +/- 20%)
If you are experiencing a problem with Hang Up, you should :
Adjust your PBX system to generate Hang Up tones as per the above specification,
or to output normal AUSTRALIAN Hang Up tones.
OR
You can set DS4 to HANG UP on Detection of ANY DTMF digit (0 to 9), from the Answering
Party once the Door Phone call is complete.
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. DS4 will terminate all
Door Phone calls at this time setting.
ELECTRO MAGNETIC INTERFERENCE
Electromagnetic Interference (EMI) from some Switch Mode Power Supplies and some
low end UPS units (Uninterruptable Power Supplies) can prevent hang up tones being
detected by DS4. Switch Mode Power Supplies are easily identified because they
do not use a transformer and are very light. If you experience a problem, TURN OFF
any SWITCH MODE POWER SUPPLIES located near DS4 (and its power supply)
and test if the problem is resolved. If the DS4 Power Supply is connected to an
Uninterruptable Power Supply, remove it and test if the problem is resolved.