Vaisala FS11 - Alarms; Alarm Messages

Chapter 7 ____________________________________________________________ Troubleshooting
VAISALA _______________________________________________________________________ 161
Alarms
Table 30 Alarm Messages
Alarm Message
Probable Cause
Remedy
TRANSMITTER
FAILURE
Transmitter not responding.
Control cable between the transmitter and
FSC102 broken or loose, check the cable.
Transmitter failed, replace the transmitter
FST102 module.
LED FAILURE
Transmitter LED intensity too
low.
Control cable between the transmitter and
FSC102 broken or loose, check the cable.
Transmitter failed, replace the transmitter
FST102 module.
RECEIVER
FAILURE
Receiver data invalid or
receiver not responding.
Control cable between the receiver and
FSC102 broken or loose, check the cable.
Receiver failed, replace the receiver FSR102
module.
POWER SUPPLY
One of the power supply
voltages out of the valid range.
Alarm in the measurement unit FSM102:
check the DC output voltage from FSP103, it
should be about 24 VDC, operated from AC
(mains) or between 11 VDC...30 VDC
(operated from battery or, for example, solar
cells). If the voltages are OK, disconnect the
receiver and transmitter control cables. If the
problem disappears, there is a short-circuit
in the control cable or the optics module. If
the problem still exists, there is a failure in
the CPU board, replace the FSC102 board.
Alarm in the interface unit: failure in the
FSC202 board, which needs to be replaced.
BACKSCATTER
HIGH
Backscatter signal level
increased. There is some
disturbance in the light path.
Clean the windows and the hoods of the
optics heads. Remove the possible
disturbance.
RECEIVER
SATURATED
Ambient light level too high on
the receiver. Caused by, for
example, sunbeam reflections
from a reflecting surface.
Turn the measurement unit in such a way
that there are no strong light reflections in
the view of the receiver.
SCATTER SIGNAL
SATURATED
There is an obstacle on the
measurement volume that
causes excessive scattering.
Remove obstacles from the measurement
volume and structures.
TEMPERATURE
SENSOR FAILURE
The Surface temperature
sensor is disconnected or
failed.
Open the measurement unit cover and
check that the temperature sensor is
connected to the FSC102 board.
Check that the resistance of the temperature
sensor is in the range of 80 to 120 Ω. If it is
not, replace the sensor.
SIGNAL OFFSET
DRIFTED
Offset drifted from zero.
Another disturbing instrument
emitting IR light nearby or other
interference problem.
Turn the measurement unit or move the
sensor further away from the interfering
sources of IR light.
CLEAN WINDOW
A high Window contamination
has been detected. The
instrument is in an
unoperational condition. The
data is invalidated.
Clean the windows following the instructions
given in section Cleaning FSM102 Windows
on page 125.