Nortel DMS-100 Series Maintenance Manual page 22

1-6 Maintenance overview
The NT6X42 card performs channel supervision message (CSM) control.
The CSM is a 40-bit message that contains 24 synchronization bits, 8
integrity bits, and 8 data bits. The system transfers the complete message
over 40 frames. The integrity bit between the peripheral module (PM) that
sends the CSM and the PM that receives the CSM must match. The CM
informs the PM of the integrity value the PM will receive. The integrity
check makes sure the integrity value follows a correct path from one PM to
another PM. The 8-bit data byte relays data about call setup, maintenance,
and other PM data.
The time switch card (NT6X44) receives pulse coded modulation (PCM)
speech data. The NT6X44 card switches the data to the correct P-side ports
and channels under unified processor (UP) directives. The time switch adds
A- and B-signaling bits and tones, and system control messages from the
message and tone card (NT6X69). The time switch makes these additions to
the correct channels on the DS-1 links.
The speech from the SMS to the RCS weakens in the Pad/Ring card
(NT6X80) with 0- to 7-dB loss. A 0- to 7-dB loss reduces echo and other
noise.
The A/B derived data link (DDL) message card (NT6X86) inserts A-, B-,
and DDL-bits in the PCM data stream. The A/B DDL NT6X86 card
extracts A-, B-, and DDL-bits from the PCM data stream.
The DS-1 interface cards (NT6X85) convert the PCM speech data from
parallel to serial format. The NT6X85 transmits the PCM speech data to the
RCS. Each 6X85 card contains two DS-1 ports, which provide two-way
voice data and signaling interface to the RCS.
The XPM peripheral loader (XPL) card (NT7X05) can reduce XPM simplex
time. The NT7X05 card allows the system to transfer XPM software loads
to the XPM. The NT7X05 card allows the system to store software loads in
local storage in an XPM unit that is in service. The NT7X05 provides
storage of XPM loads and images in a stable memory card that does not
have a mechanical base. The card allows replacement of a current loadfile
with a new loadfile. During the replacement of a file, the last image is
available for recovery actions. To transfer the software to the NTMX77,
instruct the XPM unit to load from the NT7X05 card. Use the enhanced
LOADPM command, when the PM is ManB. Use the enhanced LOADPM
command with the following parameters to load the local image:
>LOADPM [PM] LOCAL IMAGE
297-8231-550 Standard 09.01 August 1998
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