Chapter 4 _________________________________________________________________ Operation
VAISALA ________________________________________________________________________ 79
MESSAGE 5, Vaisala System Standard
Message 5 is defined according to Vaisala system standard format. All
units in the message are SI-units. The message format is as follows:
!
FSA
∀
VIS(02000(AL(0)))BL(00100(AL(0)))
#
CSUM
∃−∗
where
!
= Start of the heading
FS
= FS11 sensor identifier
A
= First character of the unit identifier, if the ID is
not defined it is replaced by a space character
∀
= Start of the text
VIS(02000(AL(0)))
= Visibility identifier and MOR value (unit
meter, 1 min average) and alarm status related
to visibility value
BL(00100(AL(0))) = Background luminance identifier and BL value
(unit cd/m
2
) and alarm status related to BL
value
#
= End of the text
CSUM
= Checksum CRC16
∃
= End of the transmission
For a list of alarm status code explanations, refer to Table 11 on page 74.
FD12 Emulation
For compatibility in the system level, the FS11 sensor also supports the
message format, frames, and polling format of Vaisala FD12 Visibility
meter and Vaisala FD12P Weather Sensor. The FD12/FD12P polling
format is accepted only when the FD12/FD12P message emulation is
selected. The FD12/FD12P polling format is as follows:
%
FD
id
message_number
−
The parameter
message_number
refers to the FD message number.
