Saving and Restoring User Settings

Recording setup and operations parameter settings for future reference is very important. If you unintentionally change these, you will need to program the correct settings back into the controller to return the equipment to operational condition.

After you program the controller and verify proper operation, use User Save Set [USr;S] (Fac- tory Page, Diagnostics Menu) to save the settings into either of two files in a special section of memory. If the settings in the controller are altered and you want to return the controller to the saved values, use User Restore Set [USr;r] (Factory Page, Diagnostics Menu) to recall one of the saved settings.

A digital input or the Function Key can also be configured to restore parameters.

Note: Only perform the above procedure when you are sure that all the correct settings are programmed into the controller. Saving the settings overwrites any previously saved collection of settings. Be sure to document all the controller settings.

Programming the Home Page

Watlow’s patented user-defined menu system improves operational efficiency. The user-defined Home Page provides you with a shortcut to monitor or change the parameter values that you use most of- ten.

You can create your own Home Page with as many as 20 of the active parameters. When a parameter normally located in the Setup Page or Operations Page is placed in the Home Page, it is accessible through both. If you change a parameter in the Home Page, it is automatically changed in its original page. If you change a parameter in its original page it is automatically changed in the Home Page.

The default parameters will automatically appear in the Home Page.

Change the list of parameters in the Home Page from the Custom Menu [CUSt] (Factory Page).

Tuning the PID Parameters

Autotuning

When an autotune is performed on the EZ-ZONE®PM, the set point is used to calculate the tuning set point.

For example, if the active set point is 200° and Autotune Set Point [A;tSP] (Operations Page, Loop Menu) is set to 90 percent, the autotune function utilizes 180° for tuning. This is also how autotun- ing works in previous Watlow Winona controllers. In addition, changing the active set point in previous controllers causes the autotune function to restart; where with the EZ-ZONE®PM changing the set point after an autotune has been started has no af- fect.

A new feature in EZ-ZONE®PM products will allow set point changes while the control is autotun- ing, this includes while running a profile or ramping. When the auto tune is initially started it will use the current set point and will disregard all set point changes until the tuning process is complete. Once complete, the controller will then use the new set point.

This is why it is a good idea to enter the active set point before initiating an autotune.

Autotuning calculates the optimum heating and/ or cooling PID parameter settings based on the sys- tem's response. Autotuning can be enabled whether or not TUNE-TUNE+™ is enabled. The PID settings generated by the autotune will be used until the au- totune feature is rerun, the PID values are manually adjusted or TRU-TUNE+®is enabled.

To initiate an autotune, set Autotune Request [`AUt] (Operations Page, Loop Menu) to [`YES]. You should not autotune while a profile is running. If the autotune cannot be completed in 60 minutes, the autotune will time-out and the original settings will take effect.

The lower display will flash between [tUnE] and the set point while the autotuning is underway. The temperature must cross the Autotune Set Point five times to complete the autotuning process. Once com- plete, the controller controls at the normal set point, using the new parameters.

Select a set point for the tune with Autotune Set Point. The Autotune Set Point is expressed as a percent of the Closed Loop Set Point.

If you need to adjust the tuning procedure's ag- gressiveness, use Autotune Aggressiveness [T;Agr] (Setup Page, Loop Menu). Select under damped [Un- dr] to bring the process value to the set point quick- ly. Select over damped [ouer] to bring the process value to the set point with minimal overshoot. Select critical damped [Crit] to balance a rapid response with minimal overshoot.

Process Set Point

Autotune begins

Autotune complete

 

 

Autotune Set Point

(90 percent of Process Set Point)

Temperature

Time

Watlow EZ-ZONE®PM Integrated Controller

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Chapter 9 Features