Line Interface
Number of channels: 4 per card, Max of 4 option cards per MIU
DSP Channel usage: Programmable Signalling Loop start
DTMF: DTMF generation for dial-out
Line Impedance: CTR21, 600R, 900R or Japan – software selectable
Return loss: >18dB 300-400Hz
Protection: “on premise” level 1 protection
Ring Trip: Min 500R, typical 800R
Ringing capability: 500R for 40Vrms into REN=3
Ring voltage: 65Vrms typical, no load
Longitudinal to metallic balance: >40dB (300-600Hz); 45dB (600-3400Hz)
Common mode rejection ratio (CMRR): >40dB 300-3400Hz
THD: <1% at 0dBm, 1kHz
Crosstalk: <-85dB (inter-channel and inter-card)
Nominal line TX level: -9dBm ± 1dB
Input level adjustment: Via software –9dB to +12dB in steps of 1.5dB
Output level adjustment: Via software –34.5dB to +12dB in steps of 1.5dB. Mute option
Freq response: 300Hz – 3200Hz ± 2dB ref to 1kHz (8kHz sampling) with all echo processing and pre-emphasis disabled hours
Connectors
Line: RJ11 2 pin modular jack socket
Phone connector pinout: Pin 3 – ring (A), Pin 4 – tip (B), other pins - unused
Ringing
Ring Cadence: US Ringtone