3. FAULT DIAGNOSIS BY LOOP-BACK TEST
This section explains loop-back diagnosis by loop-back tests.
Loop-back diagnosis by loop-back tests is available in the following three kinds.
•
Loop-Back Diagnosis from the DLI to the DRU (Paragraph 3.1)
•
Loop-Back Diagnosis between the DLI and the Transmission Equipment (Paragraph 3.2)
•
Loop-Back Diagnosis between the DRU and the Transmission Equipment (Paragraph 3.3)
3.1 Loop-Back Diagnosis from the DLI to the DRU
This paragraph explains the procedure of loop-back diagnosis from the DLI to the DRU. When the DLI
and the DRU are connected via the transmission equipment, loop-back diagnosis between the DLI and the
transmission equipment and between the DRU and the transmission equipment must be performed in ad-
vance to this loop-back diagnosis. (Refer to Paragraphs 3.2 and 3.3)
3.1.1
Procedure for Loop-Back Diagnosis from the DLI to the DRU
START
PCM lamp (red) on the DLI card illuminates.
Set SW3-1 of the DLI card to UP.
On the DLI card, various lamps are indicating as
follows.
(a) PA-DAIA card
•
LINK (G):
•
CRC (R):
•
PCM (R):
•
FRM (R):
•
MFRM (R):
•
RMT (R):
•
BLUE (R):
(b) PA-2DAIA card
•
LINK0, 1 (G):
•
ALM0, 1 (R):
•
RM/BLU0, 1 (R):
A
ON, flashing, or OFF
One or more than one
lamp illuminates.
ON, flashing, or OFF
One or more than one
lamp illuminates.
ND-45383 (E)
Check to see if the power supply to the DRU is
normal or not, and also check the connection of
the transmission line between the DLI and the
DRU.
FAULT
:
DLI is faulty
Paragraph 4.1: DLI Fault
CHAPTER 5
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