Specifications

Hardware Reference 9
C613-03023-00 REV P
Figure 4: Location of jumpers on the AT-AR021(S) BRI-S/T PIC board
You should install the termination jumpers (terminate Rx and Tx) if:
■ termination is not provided by the building wiring, and
■ the device is the only TE device on a Point-to-Point link between the NT
and the TE, or the device is the last device on an S/T bus
You should remove the termination jumpers (not terminate Rx and Tx) if:
■ termination is provided by the building wiring, or
■ the device is one of a number of devices on an S/T bus, and is not the last
device on an S/T bus
If you are unsure of whether to terminate the line or not, contact your ISDN
service provider or your authorised Allied Telesis distributor or reseller.
Warning
Do not attempt to install or remove the PIC, or change any jumpers on
the PIC, while the switch or router is connected to a power supply or a live
network. Disconnect the mains power supply, any redundant power supply, and
any cable attached to the WAN port of the PIC. Dangerous voltages may be
present on some parts of the PIC board, even if the switch or router is powered off.
Table 5: Functions of jumpers on the AT-AR021(S) BRI-S/T PIC board
Jumper Function Default
J1 100Ω termination for TX. Not installed.
J2 100Ω termination for RX. Not installed.
J4 ISDN NT mode (installed) or TE mode (not installed).
Only present on V2 hardware revision of PIC.
Not installed.
PIC CONNECTOR
ISDN RX
TERMINATION
ISDN TX
TERMINATION
J2 J1
RJ45
BRI
LED
LED
Active
D
B1
B2
AR021SC
NT MODE (V2 REV ONLY)
J4