3.4.3  Hydran 201 Sensor ................................................................................................................. 31 
3.4.4  CPU Module ............................................................................................................................... 32 
3.4.5  USB Type B Connector for Communication ................................................................... 32 
3.4.6  I/O Module ................................................................................................................................. 32 
3.5  Analog Inputs and Output ................................................................................................................. 37 
3.5.1  Analog Inputs ............................................................................................................................ 37 
3.5.2  Analog Output .......................................................................................................................... 37 
3.6  Heating System ..................................................................................................................................... 38 
3.7  Battery ...................................................................................................................................................... 38 
3.7.1  Estimated Life ........................................................................................................................... 38 
3.7.2  Battery Specifications ............................................................................................................ 39 
3.7.3  Removing the Battery ............................................................................................................ 39 
3.7.4  Replacing the Battery ............................................................................................................ 40 
3.7.5  Resetting the Clock ................................................................................................................. 40 
3.7.6  Discarding the Battery .......................................................................................................... 41 
3.8  Internal Clock .......................................................................................................................................... 41 
3.9  Nonvolatile Memory ............................................................................................................................. 42 
3.10 Additional Information ........................................................................................................................ 42 
4  HYDRAN 201CI CONTROLLERS ............................................................................................... 43 
4.1  Hydran 201Ci-C Communications Controller ............................................................................. 43 
4.1.1  Features ...................................................................................................................................... 43 
4.1.2  Description of Major Components .................................................................................... 44 
4.1.3  Description of Circuit Board ................................................................................................ 45 
4.1.4  Additional Information .......................................................................................................... 48 
4.2  Hydran 201Ci-1 One Channel Controller ...................................................................................... 48 
4.2.1  Features ...................................................................................................................................... 48 
4.2.2  Description of Major Components .................................................................................... 50 
4.2.3  Description of Circuit Board ................................................................................................ 52 
4.2.4  Additional Information .......................................................................................................... 55 
5  HYDRAN 201TI DISPLAYS & MENUS ....................................................................................... 56 
5.1  User Interface ......................................................................................................................................... 56 
5.2  User Interface Operating Modes ..................................................................................................... 57 
5.2.1  Unacknowledged Alarms Mode ......................................................................................... 58 
5.2.2  Main Display Mode ................................................................................................................. 58