Glas-Col Temp-O-Control TOT-1200, Operating Instructions Manual

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7
DESCRIPTION OF AUTO TUNING FUNCTION
Auto tuning is an internal algorithm that allows your controller to learn the characteristics
of your set-up. It will determine the right amount of power to apply to your heating
device to bring your process to the set point temperature in the least amount of time
without overshooting and will regulate the temperature as tightly as possible. It is
important for you to understand the mechanism of Proportional, Integral, and Derivative
Control in order to understand the instrument’s ability to control your process.
To auto tune the system you press the advance button one time and AUT will appear on
display. Use arrow buttons and change to YES and then press the infinity button. The
instrument immediately goes into the AUTO TUNE mode and will run for 30 min. to 90
minutes. When the AUTO TUNE mode is finished it will stop flashing between the auto
tune screen and operation screen.
* Since ON-OFF action (two-position action) takes place in the auto tune procedure, the
temperature of the process material being heated may change greatly. Do not carry out
the auto tune if the process does not allow a significant variation of the process
temperature. Use a material that is similar but expendable for the auto tune procedure.
* Re-run the auto tune again if the Set-point Value temperature (SV) is significantly
changed, the upper or lower PV temperature has changed, or if the controlled equipment
is changed.
DESCRIPTION OF PID CONTROL
“PID CONTROL”
stands for Proportional with Integral and Derivative control. It is a
mathematical method of predicting how much power must be applied to the system to
reach the Set-point temperature with a minimum of temperature oscillation (overshooting
and undershooting the set point temperature.) A brief description of each component of
PID Control is discussed below:
Proportional Control Band: The proportional band is that area around the set-point
value temperature where the power supplied to the output is neither fully ON nor fully
OFF. The proportional band can be moved to higher or lower temperatures by the integral
and derivative control parameters. For ON/OFF control, set the proportional band to “0”.