Nortel Networks Circuit Card - Manual (Page 713)

NTAK09 1.5 Mb DTI/PRI card Page 713 of 906
Circuit Card Description and Installation
NTAK93 self-test
The NTAK93 DCHI daughterboard LED is the bottom LED on the faceplate
of the NTAK09 DTI/PRI card.
The NTAK93 DCHI daughterboard does not perform a self-test when power
is applied to it. When power is applied, it turns red and remain steadily lit,
indicating the DCH is disabled. When the DCH is enabled, the LED turns
green and remains steadily lit.
Self-tests of the NTAK93 daughterboard are invoked manually by commands
in LD 96.
DTI/PRI local self-test
The local self-test, also called a local loopback test, checks speech path
continuity, zero code suppression, remote alarm detection, and A & B bit
signalling. This test is performed manually on a per-loop or per-channel basis.
The local loopback test performs a local logical loopback and does not require
any external loopback of the T1 signal.
Restrictions and limitations
The DCHI and DTI/PRI must be disabled before performing the self-test on
the entire DTI/PRI card. Individual channels must be disabled before
performing a self test on a particular channel.
Power requirements
The DTI/PRI obtains its power from the backplane, and draws less than
2 amps on +5 V, 50 mA on +12 V and 50 mA on –12 V.
Foreign and surge voltage protection
Lightning protectors must be installed between an external T1 carrier facility
and the system. For public T1 facilities, this protection is provided by the
local operating company. In a private T1 facility environment (a campus, for
example), the NTAK92 protection assembly can be used.