TABLE OF CONTENTS
1
Purpose ................................................................................................................................. 3
2
General.................................................................................................................................. 3
3
Detailed Principle of Operation ............................................................................................ 3
4
Physical Description ............................................................................................................. 6
5
Temperature Considerations ................................................................................................. 6
6
Power Interruptions .............................................................................................................. 6
7
Mounting Considerations...................................................................................................... 7
8
Wiring Diagram .................................................................................................................... 8
9
Program Examples................................................................................................................ 9
9.1
CR23X .......................................................................................................................... 9
9.2
CR1000 ....................................................................................................................... 10
APPENDIX A
1
RS-422 Output Format for non-Campbell Datalogger Applications.................................. 12
2
Built In Test (BIT) .............................................................................................................. 12
3
Hardware Built-In-Test (BIT)............................................................................................. 12
4
Continuous Built-In-Test (BIT).......................................................................................... 12
5
BIT Failure That Disables Ice Output ................................................................................ 13
6
Operator-Initiated Tests ...................................................................................................... 14
7
Initiated Built-In-Test (BIT) ............................................................................................... 15
8
Correlation Counting .......................................................................................................... 16
9
Ice Detector RS-422 String Format .................................................................................... 17
10
Electrostatic Discharge (ESD) Consideration ................................................................ 19
APPENDIX B
1
Freezing Rain Sensor Block Diagram ................................................................................ 20
1.1
Microcontroller ........................................................................................................... 21
1.2
Watchdog/Reset Circuit.............................................................................................. 21
1.3
Serial EEPROM.......................................................................................................... 21
1.4
Probe Oscillator .......................................................................................................... 21
1.5
Heater Control ............................................................................................................ 22
1.6
Drive Coil ................................................................................................................... 22
1.7
Feedback Coil ............................................................................................................. 22
1.8
Heater.......................................................................................................................... 22
1.9
DC Power Supply ....................................................................................................... 22
1.10
Status Output .............................................................................................................. 23
1.11
Ice Signal Output ........................................................................................................ 23
2
Qualification Capabilities ................................................................................................... 24
3
Input/Output Specification.................................................................................................. 25
3.1
Input/Output Pin Designations ................................................................................... 25
1
