Black Box Async 232 422/530 Manual page 16

Line Shield (JB2 and JB4)
This jumper pertains to the line interface. In the connected position, the
jumper links RJ-45 pins 2 and 7 to frame ground and the rear panel. These
pins can be used as connections for the twisted-pair cable shield. In position
2 and 3, pins 2 and 7 are disconnected from frame ground.
Position 1 & 2 = Line Shield A and B Connected to Frame Ground
Position 2 & 3 = No Shield
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.
Position 1 & 2 = DSR
Position 2 & 3 = N/A
SGND and FRGND (JB5)
In the connected position, this jumper links RJ-45 pin 5 (Signal Ground) and
frame ground through a 100-ohm,
is disconnected from frame ground.
Position 1 & 2 = SGND (Pin 5) and FRGND Connected
Position 2 & 3 = SGND (Pin 5) and FRGND Not Connected
JB2 and JB4
JB6 and JB7
JB5
CHAPTER 3: Configuration
(Do not use.)
1 ⁄ watt resistor. In the open position, pin 1
2
18