User Guide: Technical Reference
SECTION 3 OPERATING THE
ioLink 4
PRELIMINARY
Customer Support (202) 333-7031
-3-9
RF or Far-End Related Alarms
•
FEC BER > x.x E-x
•
FEC decoder not locked
•
RX Low Signal Power
•
RX Low Symbol Power
•
No
Acquisition
•
AIS (Alarm Indicator Signal)
•
This alarm indicates that the pre-FEC BER
has exceeded the BER Threshold for BER
Interval consecutive seconds. Both the
BER Threshold and the BER Interval may
be set by the user in the Advanced Menu.
•
This alarm indicates that the forward error
correction circuitry has discovered an error
in the bit stream. If this is the only alarm
condition, it is usually an indication that
there is a problem with the far-end modem.
•
This alarm is caused by a low value of
signal power being received by the RF unit.
In addition to causing the Alarm LED to
light, it will cause the RF Fault LED to light.
•
This alarm is caused by a low value of
power being received at the baseband
processor. In addition to causing the Alarm
LED to light, it will cause the RX Data LED
to be extinguished.
•
This alarm is caused by an acquisition
failure by the de-spreading circuitry. The
likely source of failure is the loss of signal
from the far end of the link.
•
This is caused by the modem receiving “all
ones” from the DSX or G.703 interface.
This indicates that a failure of the
“upstream”, or user, device has occurred.
