Nortel Networks 553-3001-211 manual Electrical specifications, Circuit power

NT1R20 Off-Premise Station Analog Line card Page 163 of 894

Port-to-port loss configuration

The loss plan for the NT1R20 OPS analog line card determines port-to-port loss for connections between an OPS analog line card unit (port) and other ports.

The transmission properties of each line unit are characterized by the OPS or ONS class of service assigned in the Analog (500/2500-type) Telephone Administration program LD 10.

The OPS analog line card provides transmission loss switching for control of end-to-end connection loss. Control of loss is a major element in controlling transmission performance parameters such as received volume, echo, noise, and crosstalk. The loss plan for the OPS analog line card determines port-to-port loss for connections between an OPS analog line card unit (port) and other IPE ports. LD 97 is used to configure systems for port-to-port loss.

See Software Input/Output: Administration (553-3001-311) for LD 97 service change instructions.

Electrical specifications

This section lists the electrical characteristics of the NT1R20 OPS analog line card.

Circuit power

The +8.5 V dc input is regulated down to +5 V dc for use by the digital logic circuits. All other power to the card is used by the line interface circuits.

The ±15.0 V dc inputs to the card are used to power the analog circuits. The +5 V dc from the module power supply is used for the analog hybrid. The –48.0 V dc input is for the telephone battery. Ringing power for telephones is 86 Vrms ac at 20 Hz on –48 V dc. The Rsync signal is used to switch the

20 Hz ringing on and off at the zero cross-over point to lengthen the life of the switching circuits.

Circuit Card Description and Installation