Nortel Networks Circuit Card User Manual

 NTAK09 1.5 Mb DTI/PRI card

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.

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. 

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. 

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.

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.