Telos Zephyr, User Manual

Page: 55 / 258

Section 4 INSTALLATION &
BASIC OP
55
The U and S/T Interface (USA & Canada)
Connect the ISDN line from the telephone central office directly to the lower RJ- 11 style
“U interface" modular jack on the rear panel ISDN interface using the standard phone
cable provided..
U
S/T
NT1
TA
Zephy r USA ISDN Interface
To Telco Line
(Standard Modular)
Normal set-up. The U jack connects directly
to the Telco line and the S/T jack is unused.
The Zephyr's S/T interface is always active, and may be used to parallel additional ISDN
terminal equipment, such as an additional Zephyr or ISDN phone set, to the line. The
internal NT1 operates just as if it were an external box in order to permit this to occur
(see diagram, below).
U Interface Status LED
The LED indicator of the status of the ISDN connection is on the rear panel near the U
jack. If the NT1 is inactive, the LED will remain in the OFF state. Activation in progress is
indicated by a rapidly blinking LED (about five times per second). If NT1 can contact
the central office, the LED will blink slowly (about once per second). The LED will come
on solid when all handshaking is completed and the basic line connection is good.
IMPORTANT!
An RJ-11 style 6-position plug can be inserted into the center
of an RJ-45 style 8-position jack if the Telco charged you extra
and installed a RJ-45 jack for your ISDN line.