Verilink DIU 2130 (880-503297-001) Product Manual - Manual (Page 44)

Troubleshooting
4-2 Verilink
• Amber
—Associated data channel is under test by an operator (a
test signal is being applied by the DIU).
• Flashing Red
—Power-up self test failure.
• Flashing Red and Amber
—DIU has failed an operator-initiated data
channel test.
• Not Lit
—DIU is not powered up (power is lost).
Loss of Clock
Alarm Notification
If the DIU 2130 detects loss of clock, it will send an alarm to the
management software and activate an LED indicator. The following
loss of clock sources can be detected upon failure:
• TIU 2850
—AMI, TTL, or RS-422
• NCC 2020 or TAC 2010 External
—TTL and RS-422
• DIU 2130
—Tail-circuit timing
Loss of Signal
Alarm Notification
A loss of signal alarm will be sent to the management software
when the DIU 2130 detects the loss of RTS or DTR handshake leads
via the cable becoming disconnected or the DTE deactivating the
leads. Access Manager and the ASCII Terminal Interface offer the
following settings for this feature:
• RTS
—Sends an alarm notification upon the loss of RTS on the
DTE interface.
• DTR
—Sends an alarm notification upon the loss of DTR on the
DTE interface.
• None
—Does not send any notification upon loss of RTS or DTR.
Test Signal
Detector
If a test signal is applied by the DIU to the selected data channel
and is looped back at the far-end DIU, the test signal detector looks
for bit errors in the returned signal. If errors are detected, the STAT
LED for that data port flashes red and yellow on the DIU front
panel. If no errors are detected, this LED lights yellow.
Data Channel
Loopbacks
The DIU 2130 provides a data channel loopback to help isolate data
channel failures. Figure 4-1 shows this loopback. When this
loopback is activated by a test operator it provides two
simultaneous connections:
• One toward the data equipment
• One toward the network
On the equipment side, the data equipment transmitter is
connected to the receiver through the DIU interface driver and
receiver circuits. This path allows the operator to verify operation
of the customer data equipment and the associated interface
cabling to the DIU.