User guide

Watlow EZ-ZONE
®
PM PID Controller • 86 • Chapter 9 Features
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 often.
You can create your own Home Page with as many as 20 of the active parameters. When a parameter nor-
mally 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 autotuning works in pre-
vious 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 affect.
A new feature in EZ-ZONE PM products will allow set point changes while the control is autotuning, 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 con-
troller 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 system's
response. Autotuning can be enabled whether or not TUNE-TUNE+
®
is enabled. The PID settings gener-
ated by the autotune will be used until
the autotune feature is rerun, the PID
values are manually adjusted or TRU-
TUNE+
®
is enabled.
To initiate an autotune, set Autotune
[`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 au-
totuning is underway. The temperature
must cross the Autotune Set Point five
times to complete the autotuning pro-
cess. Once complete, the controller con-
trols 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 aggressiveness, use Autotune Aggressiveness [T;Agr] (Setup
Page, Loop Menu). Select under damped [Undr] to bring the process value to the set point quickly. Se-
lect 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.
Time
Temperature
Autotune begins
Process Set Point
Autotune Set Point
(90 percent of Process Set Point)
Autotune complete