User's Guide _______________________________________________________________________ 
88  ___________________________________________________________________ M211107EN-C 
MESSAGE 12, Optional Message 
Message 12 provides 1 and 10 minute visibility (MOR) and background 
luminance (BL) values. Furthermore, it contains the entire status 
information and the window dirt contamination correction factors for 
FSM102 and LM21. The message format is as follows: 
!FSA∀IAL 02000000 VIS1 75000 VIS10 75000 VAL 00000000000000
 VCF 1.00 BL1 01000 BL10 01000 BAL 000000000 BCF 1.00#*CSUM
∃−∗ 
First character of the unit identifier, if the ID is 
not defined, it is replaced by a space character 
Identifying string for FSI102 interface unit 
alarm/status 
Status of FSI102 interface unit 
Identifying string for 1 minute average MOR 
1 minute average MOR in meter as provided 
by the FSM102 
Identifying string for 10 minute average MOR 
10 minute average MOR in meter 
Identifying string for FSM102 alarm/status 
Identifying string for the FSM102 window dirt 
contamination correction factor 
Window dirt contamination correction factor of 
FSM102 
Identifying string for 1 minute average 
background luminance BL 
1 minute average of the background luminance 
in cd/m2 as provided by the LM21  
Identifying string for 10 minute average 
background luminance BL  
10 minute average of the background 
luminance in cd/m2  
Identifying string for LM21 alarm/status 
Identifying string for the LM21 window dirt 
contamination correction factor 
Window dirt contamination correction factor of 
LM21