ABU (Discontinued)
ABU Master/Slave Specification
ABU front

Introduction
The analogue backup unit, ABU, has been designed for purpose of monitoring and automatically backing up analogue audio circuits via ISDN. The system is comprised of a ABU slave unit installed at the audio source and a ABU master unit installed at the transmitter site. The ABU master will continuously monitor both the left and right audio channels and implement a backup scheme determined by the type of fault detected. In the event of a total failure at the signal source the ABU master can automatically switch to a locally generated program source.

Key Features
One Integral ISDN Terminal Adapter (64Kbps / 56Kbps)
12 International ISDN Standards - User Selectable from Front Panel
Real-time Applications - 2.8ms Coding Delay
15.5KHz Mono or 7.5KHz Mono Audio Over ISDN (128Kbps - 2B Channels)
> 82dB Signal-to-Noise Ratio
Remote Configuration via Management Ports
Keypad & Crystal Clear VFD Display
85-260V AC Auto-ranging Power Supply

System Diagram
abu diagram
Audio Performance
Coding Standard
Coding Delay
Sample Rate (Fs)
Bandwidth
Format
S/N Ratio
I/P Impedance
I/P Level
I/P Connectors
O/P Impedance
O/P Level
O/P Connectors
*AUX I/P Impedance
*AUX I/P Level
*AUX I/P Connectors
Sub Band ADPCM
2.8ms at 15.6KHz
16KHz to 32KHz
5Hz to 15.6KHz @Fs=32KHz
Mono (auto monoised)
>80dB
>10K
+12dBu Max
XLR Balanced
<100R
+12dBu Max
XLR Balanced
>10K
+12dBu Max
XLR Balanced

ABU Master Rear Panel
c450xr rear

Management Port
Type
Speed
Signals
Connector
V.24 - Fixed DCE / DTE
9.6Kbps Async 8,n,1
TXD, RXD, GND
Dual 9 Way D-Type Female

ABU Master Telemetry Port
Type Connector
Contact Closure: Aux Feed In Use
Contact Closure: Left Channel Good
Contact Closure: Left Channel Good
Contact Closure: Main Feed in Use
Contact Closure: ISDN Feed in Use
Contact Closure: System in Auto
Override Signal: Force to ISDN
Override Signal: Force to Main
Override Signal: Force to Aux

COM, NC, NO
25 Way D-Type Female









ABU Slave Telemetry Port
Type
Connector

Contact Closure: ISDN Feed In Use
Contact Closure: Audio Good

COM, NC, NO
25 Way D-Type Female




CD Start Port *
Type
Connector

Contact Closure: Start Aux CD

COM, NC, NO
9 Way D-Type Female



Power Requirements
Voltage
Power
Connection
85-260 VAC 60/50Hz Auto Ranging
20W
IEC Mains Plug

Physical Properties
Enclosure
Width
Depth
Height
Weight
1U 19" Rack mount
482mm
210mm
45mm
2.0Kg

*ABU Master Only