Physical description 929
Switch SW2 - Carrier Impedance Configuration
This switch sets the carrier impedance to either 120 ohms or 75 ohms.
Twistedpair cable is usually associated with 120 ohms. Coaxial cable is
usually associated with the 75 ohms setting.
Table380
Switch SW2
Cable Type SW 2-1 SW 2-2
75 ohms Up (Off) Down(On)
120 ohms Down (On) Up (Off)
Switch SW3 - Clock Controller Configuration
This switch enables/disables(H/W) theon-board ClockController. Disable
the SW 3-2 if the on-board clock controller is not in use.
Table381
Switch SW3
Switch Down (On) Up (Off) Note
SW 3-1 ——Spare
SW 3-2 Disabled Enabled
Switch SW4 - Carrier Shield Grounding
This switch enables forthe selective grounding of the Tx / Rx pairs of the
carrier cable. Closing the switch (down position) applies Frame Ground
(FGND) to the coaxial carrier cable shield, creating a 75 ohms unbalanced
configuration. This applies only to the NTBK05CA cable.
Table382
Switch SW4
Switch Down (On) Up (Off)
SW 4-1 Rx– FGND Rx – OPEN
SW 4-2 Tx– FGND Tx – OPEN
The usual method is to ground the outer conductor of the receive coaxial
signal.The NTAK79card incor porates fouron-board dip switches. The
tables that follow provideinformation on the various settings and related
functions of these switches.
Note: The ON position for all the switchesis towards the bottom of the
card. This is indicated by a white dot printed on the board adjacent to
the bottom left corner of each individual switch.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23May 2008
Copyright© 2003-2008, Nor tel Networks
.