16
CHAPTER 3: Configuration
DTE as DSR or RI (JB6 and JB7)
Because this rear card is designed to function in more applications than the
Async 232
↔
422/530 Card, this jumper must be installed only in one position.
Place the jumper across pins 1 and 2 so that the terminal (DTE) sees DSR as
high when the rack is powered. The other positions, across pins 2 and 3, are
for Ring Indicate as defined by EIA/TIA-561. The RI function is irrelevant
(and on the Async 232
↔
422/530 Card is also disconnected) and can cause
improper operation if the jumper is installed incorrectly.
JB6 and JB7
Position 1 & 2
= DSR
Position 2 & 3
= N/A (Do not use.)
SGND and FRGND (JB5)
In the connected position, this jumper links RJ-45 pin 5 (Signal Ground) and
frame ground through a 100-ohm,
1
⁄
2
-watt resistor. In the open position, pin 1
is disconnected from frame ground.
JB5
Position 1 & 2
= SGND (Pin 5) and FRGND Connected
Position 2 & 3
= SGND (Pin 5) and FRGND Not Connected
3.3.2 RJ-45/RJ-45 J
UMPER
S
ETTINGS
Figure 3-5 shows the strap locations for the IC475C rear card. These jumpers
determine grounding characteristics for the RS-232 and twisted-pair converter
lines.