Campbell Scientific PWS100 Present Weather Sensor - Manual (Page 46)

Section 7. Operation
7.4.1.3 Message Field 10 To 19 Fixed Messages
No fixed messages have been defined yet. The user cannot change the fixed
messages.
7.4.1.4 Message Field 20 Visibility Range (m)
This field will output the average visibility range (m) calculated over the
Message_Interval defined.
7.4.1.5 Message Field 21 Present Weather Code (WMO)
This field will output the Present Weather Code (WMO) calculated over the
Message_Interval defined.
7.4.1.6 Message Field 22 Present Weather Code (METAR)
This field will output the Present Weather Code (METAR) calculated over the
Message_Interval defined.
7.4.1.7 Message Field 23 Present Weather Code (NWS)
This field will output the Present Weather Code (NWS) calculated over the
Message_Interval defined.
7.4.1.8 Message Field 24 Alarms
This field will output the Alarms. The alarms are output as a string of 16 ‘0’s
and ‘1’s delimited with spaces, for example 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1.
Each alarm has the following definition starting from the left hand side:
1. Visibility range less than alarm 1 trigger point set by user. The factory
default is 5 km.
2. Visibility range less than alarm 2 trigger point set by user. The factory
default is 1.5 km.
3. Visibility range less than alarm 3 trigger point set by user. The factory
default is 0.5 km.
4. Laser drive current greater than 80 mA. This may indicate the laser is
failing or recalibration is required.
5. Power supply voltage for dsp less than 11 V.
6. Laser window needs cleaning. There is sufficient build up on the
window that if not cleaned could reduce accuracy.
7. Upper detector window needs cleaning. There is sufficient build up on
the window that if not cleaned could reduce accuracy.
8. Lower detector window needs cleaning. There is sufficient build up on
the window that if not cleaned could reduce accuracy.
9. DC voltage of laser dirty window detector greater than 1.5 V. This can
be caused by sun directly shining into lens or a pws fault.
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