Troubleshooting guide

Table Of Contents
255
Hardware Reference
Universal and R2 NSU DIP Switch Settings
Table 30: Message Link DIP Switch Setting
DIP Switch Use Notes
Rear panel,
left side
Primary NSU Set to 1 (up). Connected to the controller
Secondary NSU Set to 2 (down). Connected to another NSU
Table 31: T1/E1 Ports DIP Switches Defined
DIP Switch Use Notes
1 Tx Ground Ground when down; floating when up.
2 Rx Ground Ground when down; floating when up.
3 Impedance selector #1 120 ohm (enabled when down).
4 Impedance selector #2 100 ohm (enabled when down).
5 Impedance selector #3 75 ohm (enabled when down).
6 LT/NT selector Up for NT; down for LT.
Table 32: T1/E1 Ports DIP Switch Settings
Impedance
(ohms)
Trunk
Mode
1 Tx
Gnd
2 Rx
Gnd
3
120
ohm
4
100
ohm
5
75
ohm
6
LT/NT
100 T1
(T1/D4)
Up Up Up Down Up Up/Down
120 E1 (PRI) Up Up Down Up Up Up/Down
75 E1 (R2) Note Note Up Up Down Up/Down
Note: The Ground setting is site-dependent. Normally, Tx is grounded and Rx
is not grounded, but that depends on which remote connection is grounded.
These switches are used only with the coaxial adapter (BNC adapter required);
leave up (floating) for twisted pair connection to the E1 port.
Note: See for Table 36 on page 257 for T1 and E1 Connector Pin Allocation for
setting dip switch 6, LT/NT.