Serial data interface (sdi) cards – Nortel Networks 1000 User Manual
Page 55
Serial Data Interface (SDI) cards
55
(tip and ring) to a 4-wire transmission path (Rx/ground and Tx/ground).
The balancing network is a transformer/analog (hybrid) circuit combination.
Signaling circuits
Signaling circuits are relays that place outgoing call
signaling onto the trunk. Signal detection circuits monitor the incoming call
signaling.
Control signals
Control signals and logic are provided when the trunk is
going to be connected to special services such as recorded announcement
and paging equipment.
Serial Data Interface (SDI) cards
The NT8D41BA QSDI paddle board provides four bidirectional
asynchronous serial ports for the system processor, and the QPC841
QSDI card also provides four. Any device that conforms to the RS-232-C
serial communication standard can be connected to these serial ports.
The electrical interface uses either standard RS-232-C signals or a special
high-speed interface that combines the high-speed differential interface
of the RS-422-A standard with the handshake signals of the RS-232-C
standard.
The RS-232-C interface is normally used when data rates are less
than 19.2 Kbps, and the cable length is less than 15.24 m (50 ft). The
high-speed interface is used when the signal rates are greater than 19.2
kbps (up to 64 kbps) and/or when the cable length is greater than 15.24
m (50 ft).
Table 8 "Serial data interface cards" (page 55)
shows compatibility
between the three SDI cards and the various switch options.
Table 8
Serial data interface cards
Compatible System Options
Card
Ports
Port types
51C, 61C
81C
NT8D41BA
4
RS-232-C asynchronous
X
X
QPC841
4
RS-232-C asynchronous
X
X
The NT8D41BA QSDI paddle board does not use a front panel. It mounts
to the rear of the backplane in the NT5D21 Core/Network module, and
does not consume a module slot. The RS-232-C connections are brought
out through special cables to the backplane I/O panel.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311
02.06
Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.