May 2001
System Hardware Manual
5 - 127
A6-32
400
0-6
42-0
1
–
R
e
le
as
e 4
.0
Ma
y 2
001
4.2.5
Connectors
CN1
Connects to backboard
CN2
Debug Port
CN3
Log Port
CN4
Expansion Header
CN5
Expansion Header
4.3
COI(8)-U( ) ETU
4.3.1
Description
The COI(8)-U13 (U19 for New Zealand) ETU provides an
interface with the Central Office. The COI ETU contains
circuitry for outside ring detection, holding, dialling and
control functions.
It also incorporates line reversal detection and busy tone
detection circuitry.
LED 8
Red
CRC
Cyclic Redundant Check (CRC)
error in frame from network OR
channel busy
LED 9
Red
Ch 0
Channel 0 busy indication
LED 10
Red
Ch 1
Channel 1 busy indication
LED 11
Red
Ch 0
Channel 2 busy indication
Table 5-5 LED Indications (Continued)
LED No.
Colour
PCB
Marking
Description
