Vaisala PWD22 - Message 2; Message 3; Message 4

USER'S GUIDE ____________________________________________________________________
52 __________________________________________________________________ M210543EN-F
Message Types
Message 2 is the standard present weather message. The length of the
STA Message 3 depends on the possible alarm and warning states.
PWD22/52 adds frame strings to the polled and automatic messages. The
content of the frame strings is presented in the following:
S
H
PW id
S
X
message body
E
X
C
R
L
F
where
S
H
=
Start of heading (ASCII 1, non-printable character)
PW
=
PWD sensor identifier
=
Space character
id
=
Unit identifier, 2 characters. If the ID is not defined, characters
space and 1 are shown.
S
X
=
Start of text (ASCII 2, non-printable character)
message body
E
X
=
End of text (ASCII 3, non-printable character)
C
R
L
F
=
CR + LF (ASCII 13 + ASCII 10)
Figure 16 below shows the contents of Messages 0, 1, and 2.
10 680 1230
←
THE FIRST ROW IS THE OUTPUT
↓↓ ↓ ↓
------ 10 min average visibility  FIELD
------- one minute average visibility  DESCRIPTIONS
- 1=hardware error, 2= hardware warning, 
3= backscatter alarm, 4= backscatter warning
- 1= visibility alarm 1, 2= visibility alarm 2,
3 = visibility alarm 3
Example with frames
□PW 1□00 680 1230□
S
H
PW 1
S
X
00 680 1230
E
X
C
R
L
F
1234567890123456789012345
NUMBERS mark the character positions.
Figure 16 Contents of Messages 0, 1, and 2