Nortel DMS-100 Series Maintenance Manual page 30

1-14 Maintenance overview
The NT6X21AD line card provides a voice and signaling interface between
the following line and channel:
The card occupies one slot in the line drawer of the LCM for use with a
P-phone telephone set. This telephone set connects to the line card with a
non-loaded (NL) pair of metal conductors. Simultaneous voice and
extended signaling services are provided on the same loop.
The transmission bandwidth on the loop divides into two frequency bands:
1 Voice channel, 300–3400Hz
2 Low level signals replace signaling channel, 6–10kHz, normal
The NT6X21AD is a single line circuit line card that is hardware backward
compatible with the NT6X21AC line card. This card must have correct DIP
switch settings for this capability. The card provides enhanced features such
as the following:
The system requires feature AE1516 to allow datafill of the NT6X21AD
card code. The system requires this feature for maintenance and diagnostics
on the following:
The following table lists the recommended DIP switch settings.
297-8211-550 Standard 05.01 August 1999
a 2-wire, analog subscriber line
one channel of the 4-wire, a 32-channel 2.56 Mb/s bit stream of the
DMS-100 Family of Digital Multiplex Switching Systems
high-voltage signaling (ringing).
the reduced messaging noise
the DIP switch selectable balance impedance
the UDLC (universal digital loop carrier) optimized operation
the DIP switch selectable (0 or –3.5dB) gain in the D/A (digital to
analog) direction
the DIP switch selectable short-loop/long-loop (slp/llp), signaling levels
the new selectable signaling level
selectable voice receive D/A level
selectable balance impedance