File
6
PRA BOARDHARDWARE
Ed. 04 3/4Réf. 3EH 21000 BSAA
ALARM LEDS
In brackets: French abbreviations
CONNECTION (120- OHM SYMMETRICAL PAIRS)
The PRA board is connected to a digital line termination (DLT) by 2 reinforced symmetrical pairs.
Cable impedance: 120 Ohms +/- 20% between 200 kHz and 1 MHz; 120 Ohms +/- 10% at 1 MHz.
We recommend using an L120-series cable (or the L204 equivalent).
The distance T2-DLT is limited by the amount of loss between the DLT and T2, which must not exceed
6 dB at 1024 kHz.
T2 Name T1 Name Function
BUSY BUSY B-channels busy (red LED lights up if at least 1 B-channel is busy)
RAI (ATD) RAI Remote frame alarm (red LED lights up on alarm)
AIS (SIA2M) AIS Too many "1"s in the 2-Mbit binary train (red LED lights up on
alarm)
NOS (MS) NSIG Absence of 2-Mbit signal (red LED lights up on alarm)
CRC (TE) CRC CRC error (red LED lights up on alarm)
LOS (PVT) NSYN Loss of frame alignment (red LED lights up on alarm)
BUS
RAI
AIS
NOS
CRC
LOS
Distribution panel
DLT
Transmission
Reception
TX
RX
ISDN ACCESS - E1 PRA-T2