Nortel Circuit Card, Installation Manual, Page: 161 / 908

NT1R20 Off-Premise Station Analog Line card Page 161 of 906
Circuit Card Description and Installation
Card interfaces
Voice and signaling interfaces
The eight line interfaces provided by the NT1R20 OPS analog line card
connect to conventional, 2-wire (tip and ring), analog line facilities. Incoming
analog voice and signaling information from a line facility is converted by the
OPS analog line card to digital form and routed to the CPU over DS-30
network loops. Conversely, digital voice and signaling information from the
CPU is sent over DS-30 network loops to the OPS analog line card where it
is converted to analog form and applied to the line facility.
The OPS analog line card uses only eight of the 30 available timeslots for its
eight line interfaces. The OPS analog line card can be configured in software
to format PCM data in the µ-law or A-law conventions.
Maintenance communication
Maintenance communication is the exchange of control and status data
between line or trunk cards and the CPU. Maintenance data is transported
through the card LAN link.
The card LAN link supports the following functions on the NT1R20 OPS
analog line card:
• polling
• reporting of self-test status
• CPU initiated card reset
• reporting of card ID (card type and hardware vintage)
• reporting of firmware version
• reporting of line interface unit configuration
• enabling/disabling of the DS-30X network loop busy
• reporting of card status
Power interface
Power is provided to the NT1R20 OPS analog line card by the NTAK78
ac/dc or NTAK72 DC power supply.