Nortel Networks Video Gaming Accessories 553-3001-211 Manual De Usuario

 NT1R20 Off-Premise Station Analog Line card

Before the appropriate balance network can be selected, the loop length 
between the near-end and the far-end station must be known. To assist in 
determining loop length, “Port-to-port loss” on 

 describes some 

typical resistance and loss values for the most common cable lengths for 
comparison with values obtained from actual measurements.

The NT1R20 OPS analog line card is designed primarily to provide an 
interface for off-premise station lines. An OPS line serves a terminal – usually 
a telephone – remote from the PBX either within the same serving area as the 

Gain treatment 
(Note 5)

No

Yes

Note 1: Configured in the Analog (500/2500-type) Telephone Administration program LD 10.

Note 2: The maximum signaling range supported by the OPS analog line card is 2300 ohms.

Note 3: Loss of untreated (no gain devices) metallic line facility. Upper loss limits correspond to 
loop resistance ranges for 26 AWG wire.

Note 4: The following are the default software impedance settings:

Termination Impedance (TIMP):

600 ohms

600 ohms

600 ohms

3CM2

Note 5: Gain treatment, such as a Voice Frequency Repeater (VFR) is required to limit the 
actual OPS loop loss to 4.5 dB, maximum. VFR treatment of metallic loops having untreated 
loss greater than 15 dB (equivalent to a maximum signaling range of 2300 ohms on 26 AWG 
wire) is not recommended.

Note 6: Jumper strap settings JX.0 and JX.1 apply to all eight units; “X” indicates the unit 
number, 0 – 7. “Off” indicates that a jumper strap is not installed across both pins on a jumper 
block. Store unused straps on the OPS analog line card by installing them on a single jumper.