User Manual

MN021-01
Page 19 of 28
Figure 16 Optical Fiber Connection Examples
12.4. Test point
An electrical test point is available on the remote unit to check the downlink optical power.
Connect the fibre coming from the local unit, power both units and measure with a multimeter
the voltage between ground and the test point. A satisfactory DL optical power will give
measurement greater than 300mV, corresponding to an optical power level of around –5dBm.
Figure 17 Remote Unit TFAF Electrical Test Point
13. Troubleshooting
REMOTE UNIT ALARM Alarm LED STATUS SEVERITY ACTION
DL AGC out of range RED Flashing MINOR
Optical power below –4dBm:
check for fiber or splices
stresses, clean optical
connectors
DL optical power too low RED Fixed MAJOR
Optical power below –6dBm:
check for fiber or splices
stresses, clean optical
connectors
DL RF amplifier 1 RED Fixed MAJOR Internal failure: replace TFAF
DL RF amplifier 2 RED Fixed MAJOR Internal failure: replace TFAF
Antenna disconnected (DC
loop)
RED Flashing MINOR
Antenna cable probably
broken or disconnected.
Antenna connected to TFAF
doesn’t support DC-loopà see
store procedure to mask
unwanted alarm
External 1 RED Fixed MAJOR External alarm 1
External 2 RED Fixed MAJOR External alarm 2
WRONG OPTIMAL