Nortel Modular ICS 7.1, Инструкция по установке

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Installing ISDN BRI terminal equipment /
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N0130943 02 Modular ICS 7.1 Installer Guide
S or T extension wiring configurations
The last connection on any ISDN S or T extension wiring must
have terminating resistors to ensure correct timing of the
signaling circuits. Failure to install terminating resistors will
degrade performance. Terminating resistors should not be
connected on a TE which is not the last connection on the loop.
Terminating resistors are provided on terminal equipment. See
the instructions that come with your TE for information about
how to enable or disable the termination, as required.
The maximum length of spur and ISDN connection cord
(the extension from the main line or bus) is 10 m (30 ft).
Refer to S reference point on page 67 and T reference points
on page 68 in the Welcome to ISDN chapter for information
about wiring arrangements for ISDN terminal equipment (TE)
on an S or T loop.
Additional power
A Norstar S or T-loop does not provide power on Power
Source 1 (PS1), Power Source (PS2), or Power Source or
Sink 3 (PS3). If you are installing ISDN terminal equipment at
the S-reference point, and the equipment requires additional
power on PS1, PS2, or PS3, then you can install a suitably-
approved power supply unit. See ANSI T1.605 or the
documentation that comes with your TE for details.
The Modular ICS does not require power on PS3.
Wiring arrangements using side circuits, also called phantom
circuits, may affect loop performance when they are used to
provide power to the TE (PS1). You must account for any
effects. For example, you may need to reduce the number of
TEs on a passive bus.