User Manual

Document name:
OMU Commands and Attributes 1.0.0 v1.0
Version:
1.0
11.2.5 Lower
Not used.
11.3 CRC – EEPROM CRC Check in Active Devices
11.3.1 Description
On a regular interval, the controller polls the active devices for the Checksum of the
EEPROM (where all radio parameters are stored). If CRC differs from expected CRC, an
alarm is triggered. This status is checked in EEPROM of the Rack Communication
Boards (RCB), Splitter Boards (SPLIT), Combiner Boards (COMB) and FiberOptic
Modules (FOMASTER).
If a failure is detected, the CRC error is flagged in the EEPROM of the active device so
that alarm status is known even after a power failure.
CRC alarms normally indicates a failing EEPROM and that module should be replaced.
11.3.2 Threshold Usage
This is a digital measurement, i.e, upper and lower thresholds are ignored.
11.3.3 Time
Time threshold configures after how many seconds in error the CRC alarm should be
triggered. Normally this is set to 1 (one).
11.3.4 Upper
Not used.
11.3.5 Lower
Not used.
11.4 ILD – Input Signal Level Downlink
11.4.1 Description
The Optical Master Unit can be configured to monitor the input signal level after the
input attenuator. This is used to ensure that signals from the donor (BTS or antennas)
always are above a defined level. If input signal level drops it means that output power
for repeaters in the system will drop too, causing decreased coverage.
11.4.2 Threshold Usage
By default, only lower threshold is configured, but it is possible to configure upper
thresholds too.
11.4.3 Time
Defines after how many consecutive seconds outside allowed interval that an alarm
should be triggered.
11.4.4 Upper
Defines above what downlink input signal level in dBm * 10 that an alarm should be
triggered.
11.4.5 Lower
Defines below what downlink input signal level in dBm * 10 that an alarm should be
triggered.
For example, configuring lower threshold as -40 means that if input signal level drops
below -4.0 dBm, an alarm will be triggered.
Note! If defining the threshold lower than lowest detectable level (as investigated with
attribute RFS), alarm source will always be measured as OK.
32(45)