Omega Engineering CN9400 Cycle-Time, O v e r v i e w, Cycle-timeselection methods, Factory set

O v e r v i e w

4

CYCLE-TIME

The choice of cycle-time is influenced by the external switching device or load. e.g. contactor, SSR, Valve. A setting that is too long for the process will cause oscillation and a setting that is too short will cause unnecessary wear to an electro-mechanical switching device.

Cycle-time selection methods

The following methods of cycle-time selection may be used:

Autotune calculated

After Autotune has been run and completed the calculated cycle- time can be manually accepted or adjusted to suit the switching device. For selection method see Select Autotune Calculated

Cycle-time.

Pre-select autotune cycle-time

The controller can be programmed to automatically accept the

calculated Autotune cycle-time. For selection method see Pre- Select Automatic Acceptance of Any Autotune Cycle-time.

Pre-select before autotune

The controller can be programmed manually with any cycle-time between 0.1 and 81 sec. This cycle-time will not be changed by any Autotune functions. For selection method see Pre-Select Cycle- time Before Autotune.

Factory set

To use the 20 sec factory set cycle-time no action is needed whether Autotune is used or not.

Further information can be programmed into the controller, see

SECOND SETPOINT, RANGING AND SETPOINT LOCK, IMPROVING CONTROL ACCURACY

Functions and options

The facilities of the controller are selected from the multi-level menu using the front panel mounted buttons.

Note: It is advisable to study this section before any programming is undertaken.

Each level within the multi-level menu offers different functions, see FUNCTIONS MENU for menu of main functions. Each function has a range of user selections or options, see FUNCTION LIST for functions and options details.

The controller has two modes, program mode and operating mode. When in program mode the controller can be programmed with settings and functions to suit the application. When in operating mode the controller uses the setting and functions entered in the program mode to control the application and also displays both the process variable and setpoint temperatures. For full details on how to program the controller see VIEWING AND SELECTING

FUNCTIONS.

Note: In this manual the letter k is represented by the character K