Vaisala CL31 - Page 4

USER'S GUIDE____________________________________________________________________
2 ___________________________________________________________________ M210482EN-D
Operation of Maintenance Terminal Connection ......39
Startup Procedure ...............................................................39
Settings for Normal Operation..............................................41
Factory Settings of User Programmable Parameters.........42
CHAPTER 4
FUNCTIONAL DESCRIPTION.....................................................................43
Theory of Operation ...............................................................43
Basic Operating Principle....................................................43
Practical Measurement Signal.............................................43
Noise Cancellation...............................................................44
Return Signal Strength........................................................45
Height Normalization...........................................................45
Backscatter Coefficient........................................................46
Vertical Visibility...................................................................46
Sky Condition Algorithm .......................................................48
General................................................................................48
Option code .........................................................................48
Activation.............................................................................49
Algorithm Overview .............................................................49
CHAPTER 5
OPERATION.................................................................................................55
Operation Modes ....................................................................55
Serial Lines - Open and Closed Port ....................................55
User Commands.....................................................................57
Data Messages........................................................................62
CL31 Data Messages No. 1 and 2 ......................................63
CRC16 Checksum..........................................................69
CL31 Status Message.........................................................70
CT12K Messages................................................................73
CT12K Digital Message No. 2........................................73
CT12K Digital Message No. 3........................................77
CT25K Data Messages .......................................................78
CT25K Data Message No. 1 ..........................................78
CT25K Data Message No. 6 ..........................................80
CT25KAM Data Messages..................................................82
CT25KAM Data Message No. 60...................................82
CT25KAM Data Message No. 61...................................82
LD40 Standard Telegram....................................................82
Telegram Structure Remarks.........................................84
Failure and Warning Messages .....................................84
Checksum Calculation....................................................87
Manual Message.................................................................88
Polling Mode ...........................................................................89
CHAPTER 6
MAINTENANCE............................................................................................91
Periodic Maintenance.............................................................91
Alarms and Warnings..........................................................91
Cleaning ..............................................................................92
Window Contamination Measurement Calibration.........92
Checking the Door Gasket ..................................................93