Troubleshooting ______________________________________________________________________
RF-MCGARDPRO
Hubbell Power Systems, Inc.
–
RFL™
Products
July 1, 2022
©2022 Hubbell Incorporated
8-15
8.6.1 Common Digital Communications Interface Troubleshooting Issues
Problem
Possible Cause
Solution
Timing/PLL
Lock Alarm
Timing not recovered from
RX signal
Remote terminal or network is not providing time
source. Verify programming.
Local time source failed
If terminal is programmed for internal timing change to
loop and set remote terminal to internal.
Loopback present
A local or remote loopback is present causing the local
terminal to communicate to itself. Remove loopback.
TX Activity
Alarm
Configuration issue
Module not enabled or timeslot not assigned to
interface. Check configuration parameters.
RX Activity
Alarm
Cabling/Connection issue
Verify cable is connected properly to interface. Verify
fiber connections are not "rolled".
Remote terminal
connections/configuration
Verify remote terminal cables are connected properly
and configuration is correct.
Remote/Yello
w Alarm
Local TX issue
Verify local TX connections. Verify fiber TX level is
within specification.
Uni-directional path failure Network configuration is causing only one direction to
communicate. Verify configuration.
Loopback
Alarm
Active loopback test
Disable interface loopback test.
RX Carrier
Loss (T1/E1)
Remote terminal
connections/ configuration
Verify remote terminal cables are connected properly
and configuration is correct.
Cabling/Connection issue
Verify cable is connected properly to interface. Verify
fiber connections are not "rolled".
RX Loss of
Sync (T1/E1)
Framing/coding mismatch
Verify framing and coding configuration matches the
T1/E1 circuit.
RX Unframed
All 1's (T1/E1)
Network communications
failure
T1/E1 network issue. Local functionality can be
confirmed with a local loopback.
Fiber frame
sync alarm
Proper signal level not
received
With fiber signal meter, verify remote terminal TX levels
are correct. Verify receive signal levels are within the
minimum receive level.