Chapter 5 _________________________________________________________ Theory of Operation 
 
VAISALA _______________________________________________________________________ 155 
Event Messages 
This section describes the Event Messages of the different units. 
The Present Weather Detector PWD32 does not support Event Messages. 
The interface unit creates PWD32 related Event Messages where 
possible. 
Table 24  Measurement Unit Event Messages 
Measured MOR above upper 
measurement range limit 
Measured MOR below lower measurement 
range limit 
Cal1:calibration procedure 
ongoing 
Measurement Unit calibration procedure is 
ongoing. 
Cal2:opaque glass test failed 
Measurement Unit calibration procedure 
failed. 
Repeat Measurement Unit calibration 
Cal8:calibration not valid 
Measurement Unit calibration not valid. 
Repeat Measurement Unit calibration 
WinCon1:contamination warning 
Measurement Unit windows contaminated. 
Clean windows in the near future. 
WinCon2:contamination alarm 
Measurement Unit windows contaminated. 
Clean windows immediately. 
Measurement Unit windows are clogged. 
Clean windows immediately. 
Measurement Unit CPU memory failure. 
If the failure persists after power-resets of 
the measurement unit, the measurement 
CPU2:visibility sample sequence 
failed 
Measurement Unit receiver or CPU failure 
CPU4:FSC measurement CPU 
internal power supply failure 
Measurement Unit CPU internal power 
supply failure 
CPU8:temperature sensor failure 
Measurement Unit CPU temperature 
sensor failure 
Tperi1:dew heater failure 
Measurement Unit transmitter dew heater 
failure 
Tperi2:hood heater failure 
Measurement Unit transmitter hood heater 
failure 
Measurement Unit transmitter light source 
aged 
Measurement Unit transmitter light source 
failure 
TwinCon1:backscatter high 
Backscatter signal level increased due to 
some disturbance in the light path 
(Measurement Unit transmitter) 
TwinCon2:backscatter 
measurement failure 
Backscatter measurement failure 
(Measurement Unit transmitter) 
TwinCon4:total reflection 
measurement failure 
Total reflection measurement failure 
(Measurement Unit transmitter)