Mitel 3300 Technician's Handbook page 265

Universal and R2 NSU DIP Switch Settings
Table 30: Message Link DIP Switch Setting
DIP Switch
Rear panel, Primary NSU
left side
Secondary NSU
Table 31: T1/E1 Ports DIP Switches Defined
DIP Switch
1 Tx Ground
2 Rx Ground
3 Impedance selector #1
4 Impedance selector #2
5 Impedance selector #3
6 LT/NT selector
Table 32: T1/E1 Ports DIP Switch Settings
Impedance
Trunk
Mode
(ohms)
100 T1
(T1/D4)
120 E1 (PRI)
75 E1 (R2)
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.
Use
Set to 1 (up). Connected to the controller
Set to 2 (down). Connected to another NSU
Use
1 Tx 2 Rx
Gnd Gnd
Up Up
Up Up
Note Note
Hardware Reference
Notes
Notes
Ground when down; floating when up.
Ground when down; floating when up.
120 ohm (enabled when down).
100 ohm (enabled when down).
75 ohm (enabled when down).
Up for NT; down for LT.
3 4
120 100
ohm ohm
Up Down
Down Up
Up Up
5
6
75
LT/NT
ohm
Up Up/Down
Up Up/Down
Down Up/Down
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