Coastcom D/I Mux III System User Manual

Chapter 5. Diagnostics
166
Table 5-2. LED INDICATIONS and PROBLEMS
L
O
C
Y
E
L
C
G
A
F
R
M
B
7
B
P
V
0
-
D
E
N
A
I
S
L
P
R
X
L
P
T
X
POSSIBLE PROBLEMS / SOLUTIONS
R Y R T1 span is set to a different frame mode than the D/I Mux III.
Access Set shelf Configuration (SC), and change frame
mode.
With a LOC alarm, for Models 30309-104/114, and 30309-
105/115, the LED colors may be Red (R), Yellow (Y), Green
(G), or slight variations on the LED color depending on
version. Even though the colors are different, the function is
the same.
R Y R Y R LIUs have lost lock with T1 span; possible causes include:
Telco is down, Smart Jack is faulty, cable between Smart
Jack and D/I Mux III is faulty, CSU/T1-IF is faulty, LIU is
faulty, or the wrong frame mode was selected in the D/I Mux
III shelf configuration.
To test: put a hard loopback on the T1 port. If the shelf
locks up to itself, then the problem may be external, or the
D/I Mux III and carrier may not be in frame sync.
R Y R R Same as above.
R Y Y R R Same as above.
R Y Y R Y R Same as above.
R Y R R The T1 span is sending a “keep-alive” signal; alarms
indicating unframed all ones. Possible causes include: a
downstream problem with the carrier, the Smart Jack is in
loopback, or carrier D/I Mux III is not transmitting a T1 signal
out.
To test: put a loop on the D/I Mux III T1 interface. If no
problems are found, the problem is with the carrier.
R Y R R R Carrier or far-end has initiated a remote loop, CSU is in
loopback.
To clear, access Operate Diagnostics (OD), and select
“Clear loopback” option for the direction from which the loop
is coming.
R Y R Y Local site has initiated a remote loop (to distant end CSU).
To clear, press the TX LP button on the LIU, or access the
OD screen and select “Clear all loopbacks”.
G B7 zero suppression coding has been selected in
configuration, resulting in errors and lockup on FAX
machines or modems used with voice cards; data circuits
may be non-functional, or may evidence massive errors.
Reconfigure, removing B7 coding.
Y If LED is flashing or on steady, may indicate Bipolar
Violations, caused by T1 span being set for B8ZS with D/I
Mux III being set for transparent or B7 zero suppression;
may also result from T1 span or D/I Mux III problems. If D/I
Mux is suspected, loop T1 interface back to itself. If BPV
remains during loop test, problem may be with the CSU, or
with the lit LIU.

Coastcom D/I Mux III System Specifications

General

Brand	Coastcom
Model	D/I Mux III System
Category	Multiplexer
Language	English