Toshiba DK14 Installation And Maintenance Manual page 343

Flowchart 8-2 No Synchronization
Before disconnecting CSU
from Telco line, notify the
T1 provider. You should also
notify the provider before
connecting the CSU.
Perform the CSU local loop back test. In this test the RDTU loop
back jumpers remain off and the CSU is placed in the local loop
back mode. (The RDTU transmit signal is looped back to its
receiver circuit.) See the CSU manufacturer's I&M documentation.
Perform the CSU network loop
back test per Figure 8-2.
Perform RDTU Network loop back
tests per Figures 8-10 and 8-11.
Yes
network test pass but still no
3
Contact the T1 provider (carrier) and request them to perform a point-to-point,
on-site, test from the NIU (demarcation point) to the far end T1 equipment.
Contact your
technical support group.
Strata DK I&M 5/00
Possible causes: No
carrier from far end;
defective CSU, NIU, or
RDTU; cable problems.
Perform RDTU self test
per "RDTU Loop Back Testing."
Did
RDTU pass the
self test
?
Yes
1
Yes
2 CSU local loop back
test pass
Did CSU
No
synchronization
?
Was problem
No
corrected by network
4
personnel
?
Check RDTU/CSU/NIU
cabling per "RDTU Cable
Run DK system programs
per "RDTU (T1) System
Correct as necessary.
No
Replace RDTU
No
and retest.
3
Is
Yes
the problem
corrected
?
No
Go to
4
Did the
Recheck cables,
No
then replace CSU.
?
Recheck cables,
the problem
then replace CSU.
corrected
Yes
End
Flowchart Symbols
Start
Installation."
Programming".
Is
fault cleared
?
Yes
End
End
Go to
4
Is
Yes
End
?
No
Go to
3
1677
T1
8-21