What Does The Ctr Parameter Do And What Should It Be Set To? 

This parameter is visible in the Operation menu of some of our advanced PID controllers and we always recommend it is set to Auto unless you are testing an output. The Operation menu is accessed by single tapping the P button on the majority of Novus Controllers. Single tapping the P button will cycle through a few basic parameters before returning you to the main screen which shows the Setpoint and Process Value. Once Ctr is set to Auto the parameter can usually be hidden from this menu to prevent accidental setting to Man/Manual.

So what is the difference? In Automatic control mode with PID Control the controller itself will calculate the correct % of output in order to maintain the setpoint. A very important point to note is that in Manual control mode the user defines the % of MV, which the controller will apply indefinitely. Manual mode will therefore disregard the setpoint and associated alarms. The output is permanently ON at the manually set MV which can be increased or decreased using the up and down arrows on the keypad.

Manual is useful for testing outputs during the commissioning phase or when faultfinding. However for day to day use it should be avoided. 

Parameter Ctr.E (Control Enabled) can be found in the Calibration cycle which is accessed by pressing and holding the P button on the controller. Setting this parameter to NO removes access from the main operation cycle. Alternatively it can be set using QuickTune software. See below for how to disable the Ctr parameter from the main screen on N1050 family controllers. 

Controller 3 in the below image shows the correct normal setting for the Ctr parameter in the N20K48 controller.