Nortel Enterprise 1000 Reference Manual page 172

Page 172 of 236
553-3023-211 Standard 1.00 June 2001
NTAK79 2.0 Mb PRI card
Switch SW1 – DCHI Configuration
This switch enables/disables the on-board DCHI and sets the operating mode
of the DCHI.
DPNSS1 mode is not supported at this time. For all other countries that do not
use DPNSS, use Q.931 mode.
Table 42
Switch SW1
Switch
SW 1-1
SW 1-2
Switch SW2 – Carrier Impedance Configuration
This switch sets the carrier impedance to either 120 ohms or 75 ohms. Twist-
ed pair cable is usually associated with 120 ohms. Coaxial cable is usually
associated with the 75 ohms setting.
Table 43
Switch SW2
Cable Type
75 ohms
120 ohms
Switch SW3 – Clock Controller Configuration
This switch enables/disables (H/W) the on-board Clock Controller. SW 3-2
should be disabled if the on-board clock controller is not in use.
Table 44
Switch SW3
Switch
SW 3-1
SW 3-2
Down (On)
enable DCHI
DPNSS1/DASS2
SW 2-1
Up (Off)
Down (On)
Down (On) Up (Off)
— —
Disabled Enabled
Up (Off)
disable DCHI
Q.931
SW 2-2
Down (On)
Up (Off)
Note
Spare