User`s guide

Diagnosing and Troubleshooting the DL3100 6-9
6
The connected DTE
device shows
intermittent errors.
Run a DTE/NET loopback to verify the physical connection between the
local DTE device and the DL3100.
If errors are
reported during
this loopback,
check the DTE
cable.
Make sure the DTE device supports the DTE port clocking option.
Use SCTE clocking for the DTE device if the application is using V.35.
Make sure the DTE device can handle the set DTE clocking speed.
The T3 ports on
the DL3100 cannot
be put into
network loopback
from the carrier.
Make sure the carrier is sending a standard FEAC loop-up code to the T3
port.
The DTE/Network
loopback does not
work towards the
locally connected
DTE device.
Make sure the DTE device can run to a DCE in loopback.
If configured for SCTE, the DTE device must be able to recognize an
inverted clock. If it does not, set the clocking to SCT.
The DL3100 has
timing and
synchronization
problems.
Make sure the timing source is set properly. To use the internal timing
source of the T3MB to generate the T3 transmit timing, set the clock
source to Internal. To use the recovered receive timing to clock the
transmit signal, set the clock source to Network. To provide clocking from
a customer-supplied external 1.544 MHz clock, set the clock source to
External. Make sure the proper T3 cables are plugged into the
corresponding ports on the DL3100.
You cannot access
the DL3100 T3
Mux from a
terminal.
The terminal must be running a VT-100 or compatible terminal emulation
program.
Make sure you are using a straight through cable with pin 8 CTS cut at
the terminal end.
Make sure the comm port parameters match the terminal’s and the
DL3100 has a unique ID. If the DL3100 is in a daisy-chain, you can
display a roll call of all unit numbers by pressing Ctrl-X five times.
Table 6-2 Troubleshooting Guide (Continued)
Problem Solution