Nortel Networks Video Gaming Accessories 553-3001-211 Manual De Usuario

 NTBK50 2.0 Mb PRI card

The line interface provides for the use of either 75 ohms coaxial or 120 ohms 
twisted pair cable. The impedance is selected by SW2, as shown in Table 246.

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. 

NTBK50 enables the shield of the Tx and/or Rx pairs of the carrier to be 
selectively grounded. Closing (down position) the on-board switch applies 
FGND to the appropriate carrier cable shield. The switch settings are shown 
in Table 247. 

75 ohms

Down (On)

120 ohms

Up (Off)

SW 4 – 1

Rx – FGND

Rx – OPEN

SW 4 – 2

Tx – FGND

Tx – OPEN