Nortel Circuit Card Installation Manual page 717

D-channel interface
The D-channel interface is a 64 Kbps maximum, full-duplex, serial bit-stream
configured as a DCE device. The data signals include receive data output,
transmit data input, receive clock output, and transmit clock output. The
receive and transmit clocks can vary slightly from each other as determined
by the transmit and receive carrier clocks.
Feature selection through software configuration for the D-channel includes:
• 56 Kbps
• 64 Kbps clear
• 64 Kbps inverted (64 Kbps restricted)
DCHI can be enabled and disabled independent of the PRI card, as long as the
PRI card is inserted in its cabinet slot. The D-channel data link cannot be
established however, unless the PRI loop is enabled.
On the NTAK09 use switch 1 and position 1 to select either the D-channel
feature or the DPNSS feature, as follows:
• OFF = D-channel
• ON = DPNSS (U.K.)
DS-1 Carrier interface
Transmitter
The transmitter takes the binary data (dual unipolar) from the PCM
transceiver and produces bipolar pulses for transmission to the external
digital facility. The DS1 transmit equalizer enables the cabling distance to
NTAK09 1.5 Mb DTI/PRI card
Circuit Card
Page 717 of 906
Description and Installation