Section 360-880-202
12
1. All channel units are busied or idled
2. A yellow alarm (AY) condition is sent to the WEST transmit facility (if CM2 or CM3 is selected, a yel-
low alarm is not sent)
3. An AIS signal is sent to the EAST transmit facility on all unassigned channels going between EAST
and secondary
4. The alarm relay for the WEST AR and AY is activated
Trunk processing will end approximately 15 seconds (1 second for CM2, immediately for CM3) after detection of
no AR alarm condition.
When the WEST receive facility receives a yellow alarm condition from a distant terminal, the unit will declare a
yellow alarm and illuminate the AY LED after detecting this condition for approximately 480 ms. At this time, the
unit will begin its trunk processing routine that will:
1. Busy or idle all channel units
2. Send AIS code to the EAST transmit facility
3. Activate the alarm relay for the West AR and AY
Trunk processing will end approximately 30 ms after detection of no yellow alarm.
When a red alarm (AR) is detected on the East facility, a yellow alarm (AY) is sent back on the East facility. If a
yellow alarm is detected on the east facility, no other action is taken. Red or yellow alarms detected on the East
facility will illuminate the respective AR and/or AY LEDs. When the red alarm condition no longer exists for
approximately 15 seconds, the yellow alarm signal will stop being sent. If no yellow or red alarm conditions are
detected, the LEDs will turn off.
4.8
Loopbacks
The ST1U provides three different types of loopbacks. All of the far-end loopbacks require a remote control link
between the near-end and far-end 360-80s. The line near-end loops the data back toward the customer of drop-
side. Far-end loopbacks can be either payload or line. The far-end payload loopback will loopback only the time
slots in the T1, but not the framing. The far-end line loopback will loopback all timeslots and the framing of the T1.
The card also responds to all standard CSU and T1 loopback codes.
5.
INSTALLATION
5.1
Installing the Unit
Multichannel Unit
Multichannel Unit
Primary T1 Controller (T1-S)
(channels 13−24)
(channels 1−12)
(channels 25
−
30)
Multichannel Unit
or Secondary T1
Unit
Figure 14.
360-80 ICB Common Equipment Configuration
5.1.1. Attaching the Rear Panel
The rear panel of the unit should be installed before the unit is installed in the shelf, and before wiring begins.
