xr
XRT83SL28
REV. 1.0.0
8-CHANNEL E1 SHORT-HAUL LINE INTERFACE UNIT
3.2.6
Receive Interface with N+1 Redundancy
For N+1 redundancy, the receivers on all cards can be programmed for internal impedance. The receivers on
the backup card do not have to be tri-stated. To swap the primary card, close the desired relays. See Figure
Figure 24 for a simplified block diagram of the receive section for an N+1 redundancy scheme.
FIGURE 24. SIMPLIFIED BLOCK DIAGRAM OF THE RECEIVE INTERFACE FOR N+1 REDUNDANCY
Backplane Interface
Line Interface Card
Primary Card
XRT83SL28
Rx
1:1
1:1
1:1
E1 Line
E1 Line
E1 Line
Internal Impedance
Primary Card
XRT83SL28
Rx
Internal Impedance
Primary Card
XRT83SL28
Rx
Internal Impedance
Backup Card
XRT83SL28
Rx
Internal Impedance
29
EXAR [ EXAR CORPORATION ]
