Nortel Meridian 1 Option 11C Manual page 49

Set the switches found on the circuit card as per the requirements of your
specific installation.
Switch SW1—DCHI Configuration (NTAK93 only)
This switch enables/disables the DCHI and sets the operating mode of the
DCHI. It is only used if an NTAK93 D-channel handler daughterboard is
being used. It has no effect when using the NTBK51 DDCH daughterboard.
For the U.K., use DPNSS1 mode. For all other countries, use Q.931 mode.
Table 14
Switch SW1
Switch
SW 1-1
SW 1-2
Switch SW2—Carrier Impedance Configuration
This switch sets the carrier impedance to either 120¾ or 75¾. Twisted pair
cable is usually associated with 120¾. Coaxial cable is usually associated
with the 75¾ setting.
Table 15
Switch SW2
Cable Type
75¾
120¾
Switch SW4—Carrier Shield Grounding
This switch allows for the selective grounding of the Tx and/or Rx pairs of
the carrier cable. Closing the switch (down position) applies Frame Ground
(FGND) to the coaxial carrier cable shield, creating a 75¾ unbalanced
configuration. This applies only to the NTBK05CA cable.
2.0 Mb PRI Implementation
Down (On)
—
DPNSS1/DASS2
SW 2-1
Down (On)
Up (Off)
Page 49 of 126
Up (Off)
—
Q.931
Option 11C 2.0 Mb DTI/PRI