Chapter 4 ________________________________________________________________ Operation
VAISALA _______________________________________________________________________ 65
An example of the 'X1TA' telegram and a message interpretation are
presented below:
☺
X1TA_8_015_00.00.00_00:00_00875_11150_NODET_0100_0325_N
ODT_11300025_ft_01_00000000_96
↵
where
☺
= Start-of-text character
X
= Sensor type (X LD40)
1
= Sensor ID number (0 to 9..ABC..MN)
TA
= Text telegram
8
= Instrument type, Always 8 = LD40
015
= Telegram update time or message interval in seconds
00.00.00
= Always (Date N/A))
00:00
= Always (Time N/A)
00875
= First cloud layer
11175
= Second cloud layer
NODET
= Third cloud layer (in this case: not detected)
0100
= Penetration depth of laser beam into first cloud layer
0325
= Penetration depth of laser beam into second cloud
layer
NODT
= Penetration depth of laser beam into third cloud layer
11300
= Vertical visibility
11600
= Maximum range of detection
+025
= Cloud height offset (in this case the ceilometer is
situated 25 ft above the runway level)
f
= Dimensions of all values between byte 26 and byte 76
(ft or m_)
00
= Always (Precipitation index. N/A)
00000000 = System status and messages
96
= Checksum (This value is only an example; the correct
value may be different from this one.)
↵
= Carriage Line feed
♦
= End-of-transmission character
NOTE
The notation '_' stands for a space character.