4RF Aprisa XE User Manual - page 247
Specifications | 246
DFXO Dual foreign exchange office interface
General
Audio
64 kbit/s (PCM as per ITU G.711)
32, 24 and 16 kbit/s (ADPCM as per ITU G.726 and ANSI
TI.303)
Signalling allocation
8 or 32 kbit/s allocated for CAS
Companding
A-Law or µ-Law
Maximum line length
600 metres (2000 feet) on 0.4 mm / 26 AWG copper pair
Calling line ID (CLI)
Support provided for ETSI: EN 300 659-1 & 2 and BT: SIN
227 and 242
Fax
Conforms to G3 standard for 64 kbit/s PCM and 32 kbit/s
ADPCM compression
Analogue
Transmission performance
characteristics
ITU G.712 E2 for an operating level range of -6 dBr to +1 dBr
Input level range
-10 dBr to +1.0 dBr in 0.5 dB steps
Output level range
-10 dBr to +1.0 dBr in 0.5 dB steps
Default Input level
-4.0 dBr
Default Output level
-1.0 dBr
Maximum level
+3.14 dBm0
Line impedance / Hybrid
balance impedance options
600 Ω
900 Ω
600 Ω + 2.16 µF
900 Ω + 2.16 µF
270 Ω + 750 Ω || 150 nF (TBR-21)
220 Ω + 820 Ω || 120 nF (TN12)
370 Ω + 620 Ω || 310 nF (BT3)
320 Ω + 1050 Ω || 210 nF (BT Network)
200 Ω + 680 Ω || 100 nF (China)
Return Loss
better than 20 dB over the frequency range 200 - 3600 Hz
Trans hybrid loss
better than 30 dB between 300 - 3400 Hz (with matched
external line and hybrid balance impedance)
Common mode rejection ratio better than 40 dB over the frequency range 50 - 3600 Hz
Echo Canceller
provides up to 64 ms of echo cancellation