Nortel Networks 553-3001-211 manual Application, Off-premise station application

NT1R20 Off-Premise Station Analog Line card Page 173 of 894

Table 70

OPS analog line card – configuration (Part 2 of 2)

Application	On-premise station (ONS)	Off-premise station (OPS)
Gain treatment	No		Yes
(Note 5)

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:

	ONP CLS	OPX CLS
Termination Impedance (TIMP):	600 ohms	600 ohms
Balanced Impedance (BIMP):	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.

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 page 178 describes some typical resistance and loss values for the most common cable lengths for comparison with values obtained from actual measurements.

Application

Off-premise station application

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

Circuit Card Description and Installation