let it cool down. It will repeat this heat/cool cycle several times. Based on the response
time of the whole cooking system, the controller will calculate and set the PID
parameters for your cooker.
Figure 4
Before using the auto-tune function, you must set the cooking equipment up in the exact
configuration it will be used. For example, to tune a rice cooker, place the sensor in the
room temperature pot filled with water and plug the cooker into the controller. If the
cooker has its own thermostat or power control, turn both as high as they’ll go. Set the
controller to the appropriate power level (see next Section). Turn the controller and
cooker on, and then enter the desired set point temperature closed to your normal
cooking temperature.
To activate auto-tuning, just enter code 166 to get into the PID setting menu. Set A
Γ
to 1
then exit the menu (see Fig 5). The display will start to flash alternately between A
Γ
and
the current water bath temperature, which indicates auto-tuning is in progress. When the
display stops flashing, the auto-tuning is finished. Now, the newly calculated PID
parameters are set and are used for the system. The new parameters will store in the
memory even the power is off.
You should always write down your old PID parameters, before letting the controller to
perform auto-tuning. This way if something goes wrong, you can always go back to your
old PID parameters. The water amount in the pot should be the same volume as you
would have normally used. Basically, you must setup your cooking system close to your
actual cooking environment.
The duration of auto-tuning depends on how fast the system is responding to the heating
and cooling cycle. If the temperature of the cooker takes a long time to drop -when
heater is off- the auto-tuning could be a very long tuning process. This is especially true
with a well insulated cooker. The auto-tuning should be able to tune most of your chosen
with fairly good result.
6.2 Manual Setting the PID parameter
.
9
