15
Connecting the DHY-04 TBU 3
It is recommended that the auto-disconnect feature be used when the
ringing detector is enabled.
Note:
The remote lamp tally mimics the front panel line connect button
lamp, i.e. it flashes when ringing and is on when the line is held.
The hybrid unit now behaves as a 4-wire to 2-wire converter with signal
inputs at the mic/line input connector and telephone signal output at the
output connector.
The call may be cleared by re-pressing the line connect button, or by means
of the remote divert switch, or via the serial or Ethernet ports. The call can
also be cleared automatically by enabling the auto-disconnect feature.
With both auto-answer and auto-disconnect in use, call handling can be
completely automatic in operation (settings SW3 & SW4 ON).
Integrated Ringing Detector – Auto Answer
Ringing detectors can be used when you need to answer a call
automatically, for instance: If a journalist files a report to a recorder over a
telephone line, the call can be picked up after a set number of rings by the
ringing detector. The DHY-04 has a built in ring detector that is enabled by
setting SW4 on the rear panel.
Making a Call
To initiate a call, lift the handset and dial the required telephone number.
When the call has been established, press the line connect button and the
call will be handed over to the telephone hybrid unit. To clear the line at the
end of the call, press the line connect button. The line connect button lamp
is off in the non-connected mode and illuminated in the connected mode.
The DHY-04 is also capable of making outgoing calls via DTMF dialling by
using the serial or Ethernet ports.
If the line is not connected to a valid telephone system (determined by no
line voltage present) then trying to connect is invalid. Pressing the line hold
button will cause it to flash twice quickly. If the attempt to connect is via
the serial port then the DHY-04 returns an ERR:08 error message.
Using Speed Dial Buttons
There are also 4 Speed Dial buttons on the front panel that can make
calls to 7 numbers setup via the webserver. When dialling, the unit shows
the dialling by a rotating illumination pattern on these buttons. Speed
Dial 1-4 are accessed by simple press on buttons 1-4, Speed Dial 5-7 and
last number redial are accessed by pressing and holding buttons 1-4
respectively.
Call Established
Level Setting
The DHY-04 hybrid operation is optimised for signals around 0dB. The front
panel gain switches can adjust the signal levels for both caller and sender.
The default position for these switches is receive gain (upper) fully counter-
clockwise (6dB) and the transmit gain (lower) to be in the middle (0dB). Set
the lower switch so that the bargraph normally shows 0dB (second yellow
LED) with occasional peak signal levels illuminating s6db (first red
LED). If your mixing desk or source audio is only sent at consumer level then
J1 should be fitted on the PCB (See page 5 for details of this)
DTMF Detection
The caller can use this feature in conjunction with auto answer to force
external actions from the DHY-04. Once again in the case of a journalist
ringing in a report, they can press a key on the telephone keypad to switch
on an external recorder. The key used is set by the value in the webserver
(Configuration - Remote page 26). The presence of the DTMF tones in the
incoming signal for the chosen key will activate the output on the remote
connector.
Integrated Disconnect Detector – Auto Disconnect
The DHY-04 can detect when a call has been dropped by the caller and
can release the line. There are a variety of ways that the central exchange
