Toshiba Strata AirLink DK40i, Installation And Maintenance Manual

Page: 343 / 724

T1
Flowchart Symbols
Strata DK I&M 6/00
8-21
T1
Flowchart 8-2 No Synchronization
Possible causes: No
carrier from far end;
defective CSU, NIU, or
RDTU; cable problems.
Is
fault cleared
?
Yes
No
Check RDTU/CSU/NIU
cabling per “RDTU Cable
Installation.”
Run DK system programs
per “RDTU (T1) System
Programming”.
Correct as necessary.
Perform RDTU self test
per “RDTU Loop Back Testing.”
Before disconnecting CSU
from Telco line, notify the
T1 provider. You should also
notify the provider before
connecting the CSU.
Did
RDTU pass the
self test
?
No
Replace RDTU
and retest.
Yes
3
1
Start
End
End
Yes
Go to
4
Is
the problem
corrected
?
No
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.
Did the
CSU local loop back
test pass
?
Go to
4
Recheck cables,
then replace CSU.
No
2
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
Did CSU
network test pass but still no
synchronization
?
Recheck cables,
then replace CSU.
No
Go to
3
Is
the problem
corrected
?
Yes
No
3
Yes
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.
Was problem
corrected by network
personnel
?
Yes
End
4
Contact your
technical support group.
No
End
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