Nortel Networks Circuit Card 311 - Manual (Page 901)

Architecture 901
the clock controller. The secondary reference is obtained from another 2
Mbps DTI card, which is designated by a craft person. No other clocks
originating from other 2MB DTI packs are used.
The clock controller provides an external timing interface and is capable
of accepting two signals as timing references. In this case, an external
reference refers to an auxiliary timing source which is bridged from a traffic
carrying signal. This is not intended to be a dedicated non-traffic bearing
timing signal. The clock controller uses either the two external/auxiliary
references or the 2MB DTI references.
See "Reference clock selection through software" (page 951) .
Reference clock interface
The recovered clock derived from the facility is available on the MDF
connector. The signals at these connectors conform to the electrical
characteristics of the EIA RS-422 standard.
The recovered clock derived from the facility is available on the MDF
connector. The signals at these connectors conform to the electrical
characteristics of the EIA RS-422 standard.
The recovered clock derived from the facility is available on the MDF
connector. The signals at these connectors conform to the electrical
characteristics of the EIA RS-422 standard.
Switch settings
Various 2MB DTI switch options exist on the NTAK10. These are shown in
Table 368 "2 MB DTI switch options" (page 901) .
Table 368
2 MB DTI switch options
Switch
Off
(Switch Open) On
(Switch Closed)
S1-1 — —
S1-2 CC Enabled CC Disabled
S2-1 120 ohms 75 ohms
S2-2 75 ohms 120 ohms
S3-1 non-French Firmware French Firmware
S3-2 — —
Note: The ON position for all the switches is toward the bottom of the
card. This is indicated by a white dot printed on the board next to the
bottom left corner of each individual switch.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
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