134.3 KeypadThe keypad consists of 4 directional arrows and 4 function keys. The arrow keys are used to move theadjustment cursor and change settings, while the function keys are used to enter values, and navigatethe various menu screens. The function keys are ENTER, EXIT, NEXT and PREV (previous). Use theNEXT and PREV keys to scroll through the various menu choices. ENTER is used to enter a submenuand to enter a value. EXIT is used to back up one menu level. If you are at the main menu level, EXITwill return you to the summary screen.To change a value in a submenu, the left/right arrow keys move the cursor left and right to each digitor option that can be changed. The up/down arrows will change numeric values up or down, or scrollthrough option choices. Press ENTER only when you have finished making ALL of the changes forthat menu screen.4.4 Access CodeThe WDIS series controller is shipped with the access code disabled. If you wish to enable it, seeSection 5.10 for operation. With the access code enabled, any user can view parameter settings, butnot change them. Note that this provides protection only against casual tampering. Use a lock on thecover latch if you need more protection.4.5 StartupInitial StartupAfter having mounted the enclosure and wired the unit, the controller is ready to be started.Plug in the controller and turn "ON" the power switch to supply power to the unit. The display willbriefly show the WDIS model number and then revert to the normal summary screen. Scroll throughthe menus and calibrate the sensor, and set the control parameters as detailed in Section 5, Operation.To return to the summary screen, press the EXIT key until you return to this screen. The controller willautomatically return to this screen after 10 minutes.ConditioningThe sensor requires conditioning to acclimate the electrodes prior to generating stable readings.Conditioning consists of installing the sensor in the flow cell, ensuring that the sensor remains wet atall times and supplying power to the sensor.The following conditioning times are recommended:New Sensor: 12-24 hoursAfter membrane or electrolyte replacement: 1 hour