Nortel DMS-100 Series Maintenance Manual page 48

2-28 Star Remote System hardware
NT6X21AC line card, the "NT6X21AD THL limits" table is for the
NT6X21AD line card.
Table 2-9 NT6X21AC THL limits
Frequency
Minimum
Maximum
Table 2-10 NT6X21AD THL limits
Frequency
Minimum
Maximum
Both limits are required so the system software can determine which digital to
analog (D/A) gain is selected on the line card. The software also compares
THL test results against both possible limits.
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See the following figure for a functional block diagram of the standard line
drawer. All the components of this figure are discussed in this chapter.
297-8353-550 Standard 05.01 March 2001
304
-6.2
+1.3
304
-2.7
+4.8
Data line card (DLC) (NT6X71AA, AB, AC, BA). The data line card
provides data transmission interfaces for operation with computer
terminals.
Asynchronous interface line card (AILC) (NT6X76AA, AC, AD). The
AILC provides an interface between a four-wire, RS-422 line and one
channel of the 32-channel, 2.56 Mbit/s digital bit stream. The AILC is in
two adjacent plug-in line card positions in the line drawer.
Data above voice line card (DAVLC) (NT6X87AB). The DAVLC
provides circuit-switched data for subscribers connected to a SuperNode
switch. This card allows simultaneous voice and data service over a single
pair of wires between the central office and the subscriber. The DAVLC
occupies four slots in the line drawer and requires four vertical slots, two
in each of the two logical drawers.
Integrated bit error rate test (IBERT) line card (NT6X99AA). The IBERT
line card provides bit error rate performance (BERP), which tests
transmission paths for determining bit error performance of Star Hub
hardware components.
704 1505
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+0.8 +0.8
704 1505
-2.7 -2.7
+4.3 +4.3
3204
-7.2
+0.7
3204
-3.7
+4.2