What is Rx power low alarm in cisco (optics)?

Question

System administration

catalyst 4500
is the optical cable broken? or not suitable? not very strong in optics

Te2/2Rx power low alarm; Operating value: -11.9 dBm, Threshold value: -9.9 dBm.

NAME: "TenGigabitEthernet2/2", DESCR: "SFP-10Gbase-SR"
PID: SFP-10G-SR , VID: V03 , SN: AGA162740AU

RT02-1#sh interfaces transceiver detail 
mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable.
++ : high alarm, +  : high warning, -  : low warning, -- : low alarm.
A2D readouts (if they differ), are reported in parentheses.
The threshold values are calibrated.

                              High Alarm  High Warn  Low Warn   Low Alarm
          Temperature         Threshold   Threshold  Threshold  Threshold
Port       (Celsius)          (Celsius)   (Celsius)  (Celsius)  (Celsius)
--------- ------------------  ----------  ---------  ---------  ---------
Te1/1       28.5                75.0        70.0         0.0       -5.0
Te1/2       25.6                75.0        70.0         0.0       -5.0
Te2/1       24.0                75.0        70.0         0.0       -5.0
Te2/2       23.9                75.0        70.0         0.0       -5.0
Te2/4       23.9                75.0        70.0         0.0       -5.0
Te2/5       21.5                75.0        70.0         0.0       -5.0
Te2/7       22.9                75.0        70.0         0.0       -5.0
Te2/10      22.2                75.0        70.0         0.0       -5.0

                              High Alarm  High Warn  Low Warn   Low Alarm
           Voltage            Threshold   Threshold  Threshold  Threshold
Port       (Volts)            (Volts)     (Volts)    (Volts)    (Volts)
---------  ---------------    ----------  ---------  ---------  ---------
Te1/1      3.28                  3.60        3.50        3.10       3.00
Te1/2      3.28                  3.60        3.50        3.10       3.00
Te2/1      3.29                  3.60        3.50        3.10       3.00
Te2/2      3.29                  3.60        3.50        3.10       3.00
Te2/4      3.29                  3.60        3.50        3.10       3.00
Te2/5      3.30                  3.60        3.50        3.10       3.00
Te2/7      3.29                  3.60        3.50        3.10       3.00
Te2/10     3.29                  3.60        3.50        3.10       3.00

           Optical            High Alarm  High Warn  Low Warn   Low Alarm
           Transmit Power     Threshold   Threshold  Threshold  Threshold
Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm)
---------  -----------------  ----------  ---------  ---------  ---------
Te1/1       -2.3                 1.6        -1.3        -7.3      -11.3
Te1/2       -2.5                 1.6        -1.3        -7.3      -11.3
Te2/1       -2.5                 1.6        -1.3        -7.3      -11.3
Te2/2       -2.3                 1.6        -1.3        -7.3      -11.3
Te2/4       -2.5                 1.6        -1.3        -7.3      -11.3
Te2/5       N/A                  1.6        -1.3        -7.3      -11.3
Te2/7       -2.4                 1.6        -1.3        -7.3      -11.3
Te2/10      -2.5                 1.6        -1.3        -7.3      -11.3

           Optical            High Alarm  High Warn  Low Warn   Low Alarm
           Receive Power      Threshold   Threshold  Threshold  Threshold
Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm)
-------    -----------------  ----------  ---------  ---------  ---------
Te1/1       -2.1                 1.9        -1.0        -9.9      -13.9
Te1/2       -3.5                 1.9        -1.0        -9.9      -13.9
Te2/1       -2.7                 1.9        -1.0        -9.9      -13.9
Te2/2      -11.8                 1.9        -1.0        -9.9      -13.9
Te2/4       -3.2                 1.9        -1.0        -9.9      -13.9
Te2/5      -40.0                 1.9        -1.0        -9.9      -13.9
Te2/7       -2.5                 1.9        -1.0        -9.9      -13.9
Te2/10      -2.4                 1.9        -1.0        -9.9      -13.9


RT02-1#

Te2 / 5 disabled - there is an empty one at the other end.

Answer 1

The attenuation is too great.