Instruction manual

ACU-1000 Operations Manual
Interoperability Now 5-11
5.9 LP-2 Module
5.9.1 General Description LP-2
The Local Phone Module is the interface to the ACU system for 2-wire devices, which generate
dialing information such as a telephone set. This module contains a loop current generator,
ring voltage generator, dial and busy tone generators, a DSP hybrid with VOX and a DTMF
generator/receiver.
5.9.2 LP-2 Specifications
Table 5-4 LP-2 Specifications
2-Wire Telephone Set Interface
Telephone Set Input/Output Levels
Jumper-selectable to –9, -12, or-15 dBm.
Input/Output Impedance to Telephone Set
600
Ω
Nominal.
Loop Current
Jumper-selectable 20 mA or 50 mA.
Loop Voltage
-12V standard.
Ring Voltage
20 Hz, 80V p-p square wave.
2-Wire
Distortion
Less than 0.5%.
Noise Floor
-65 dBm.
VOX Thresholds
Off, Low, Medium, High; Programmable.
VOX Hang Time
0.5, 1.0, 1.5, 2.0 seconds, Programmable.
Hybrid Balance/Adaptation Speed
-30 dB over 300 to 3200 Hz BW within 1.25 seconds;
measured with white noise source into 600 Ohms.
Ultimate Hybrid Balance
-50 dB typical over 300 to 3200 Hz BW; measured with
a single tone into 600 Ohms.
Digital Inputs (/AUXI1, /AUXI 2, /PTT)
Standard Polarity
Active Low.
Threshold
2.5V nominal.
Input Impedance
47kΩto +5V.
Protection
+100V.
Digital Outputs (/AUXO1, /AUXO2, /VOX)
Standard Polarity
Active Low.
Type
Open Drain, weak pull-up 47k
Ω
to +5V.
Maximum Voltage
+60V.
On Resistance
5
Ω
nominal.
Maximum Current Sink
50 mA.
General
Front Panel
Monitor, Ring, Off Hook, VOX, and Fault LEDs.
Rear
60 Pin PC edge connector for backplane.
Input Power
+12V, +Bus Voltage supplied by the backplane.
Size
4HP-Wide Eurocard Module: 5’’H x 0.8’’W x 9’’D.
Weight
1.0 lb. (0.5kg).