20
HIGH-SPEED 2-WIRE SHORT-RANGE DSL LINE DRIVER RACK CARD
Table 3-8 provides an overview of interface strap functions for the rear interface
cards. Following the table overview are detailed descriptions of each strap’s
function.
Table 3-8. Interface card strap summary.
Strap
Function
Position 1 and 2 Position 2 and 3
JB3
DTE Shield (Pin 1) and FRGND
Connected
Open*
JB4
FRGND and SGND
Connected
Open*
*Default setting
DTE Shield (DB25 Pin 1) and FRGND (JB3)
In the connected position, this strap links DB25 pin 1 and frame ground. In the
open position, pin 1 is disconnected from frame ground.
Table 3-9. DTE shield and FRGND.
JB3
Position 1 & 2 = DTE Shield (Pin 1) and FRGND connected
Position 2 & 3 = DTE Shield (Pin 1) and FRGND not connected
FRGND and SGND (JB4)
In the connected position, this strap links DB25 pin 7 (signal ground) and frame
ground through a 100-ohm resistor. In the open position, pin 7 is connected
directly to frame ground.
Table 3-10. FRGND and SGND.
JB4
Position 1 & 2 = SGND (Pin 7) and FRGND connected through a 100-ohm
resistor
Position 2 & 3 = SGND (Pin 7) and FRGND directly connected
