MULTI-FUNCTION LD CARD
Table 3-5, below, provides a summary of the functions of these jumpers. The functions are described in more detail afterward.
Table 3-5. Summary of Interface-Module Jumper Functions
Jumper | Function | Pos. 1 & 2 | Pos. 2 & 3 | |
| | | | |
JB2 | Line Shield and FGND | Connected | N/C* | |
JB3 | PGND (DTE Pin 1) and FGND | Connected | N/C* | |
JB4 | SGND and FGND | Connected | N/C* | |
| | | | |
*factory-default settings
Line Interface: Line Shield Connection to Frame Ground (JB2)
This jumper applies to the line interface. When this jumper is in positions 1 and 2, it links RJ-11 Pins 1 and 6 or RJ-45 Pins 2 and 7 on the corresponding line to the interface module’s frame ground. (If you are using shielded twisted-pair cable, the shield can be connected to these pins.) In positions 2 and 3, RJ-11 Pins 1 and 6 or RJ-45 Pins 2 and 7 remain connected to each other, but are disconnected (“lifted”) from frame ground.
JB2
Positions 1 and 2 = Line Shield and FGND Connected
Positions 2 and 3 = Line Shield and FGND Not Connected (default)
CAUTION!
If you connect shield to frame ground, make sure that RJ-11 Pins 1 and 6 or RJ-45 Pins 2 and 7, as well as the cable shield, are connected to ground at one end of the cable only. Connecting them at both ends of the cable will defeat the transformer isolation and will leave your system open to damage from ground loops.
