2
Phone In 6 User Handbook
1
INTRODUCTION
INTR
ODUC
TION
The Base Console has 3 module positions on the rear panel into which either of the PI-PSTN2
(2 x analogue telephone lines) or PI-ISDN2 (2 x ISDN B channels) modules can be fitted. The
Base Console is capable of connecting internal DSP and hybrid circuits to any 2 lines and
routing these out to a studio mixing desk.
The Phone In 6 uses an echo-cancellation DSP (digital signal processing) algorithm and
impedance matching to give around 70dB cancellation, which provides excellent separation
of caller & line send audio and elimination of feedback, distortion & echo on the incoming
calls. This is close to being the best performance possible on a telephone line & uses the
same enhanced echo cancellation algorithms as used on the DHY-03 telephone hybrid,
the best performing telephone hybrid in the world. The DSP, which uses 24bit variables
and at least 48bit math algorithms, can also monitor the call progress tones for various
disconnection arrangements. The audio data is supplied to the DSP from analogue inputs
via 24bit ADCs.
System Diagram
PI-6C Base Console
PI-6R Remote Control Panel
PSTN Module
or ISDN
Module x3
Music
On Hold
ADC
Hybrid 1 Port
or Conference
Port
Remote
Headset
Router/
Switcher
DSP
Ethernet
Port
Serial
Port
LED
Indicators
Gain
Switches
Bargraph
Meters
Hybrid 2 Port
6
Data
Controls
Fig 1-3: System Block Diagrams
Headset
Input
Analogue
Amplification
Headset
Connection
Microcontroller
Ethernet
Port
Caller Status
Buttons & LEDs
Spinwheel
Selector
LCD
Module
Keypad