Super Systems 9200 - Manual (Page 35)

Model 9200 Programmable Dual-loop Controller
SSi Manual SERIES 9200 35 Programmable Dual-loop
output. When the limited relay option is selected, the “Tuning Delta:” label and the Edit button will be
displayed. When the Relay option is selected, the “Tuning Delta:” label and the Edit button will be
hidden. The “Tuning Delta:” value will be the amount to limit the controller by. Pressing the Edit button
will display the numeric keypad, which will allow the user to enter the limiting value.
The current value will be displayed at the top of the
screen. Enter the new value and press the Enter
button to set the value. Pressing the Esc button will
cancel the change.
The “Conservative” option will allow the user to
minimize, if not remove, the possibility for an
overshoot of the setpoint. If a small overshoot is
acceptable, leave the “Conservative” checkbox
unchecked. If, however, no overshoot is desired,
then checking the “Conservative” checkbox will
accomplish this.
Pressing the Start button will begin the auto tune
process. Note: The process may take a few
seconds to start . The “Idle” line will change to display the calibration process for the auto tune. The line
will display a pointer value, along with the process
variable value and the setpoint.
Note: The Start button will be disabled while the
calibration is running . Pressing the Abort button will abort the process. If the Cancel button is pressed
while a calibration is running, a message box will be displayed
confirming the action.
Pressing the Yes button will stop the auto tune calibration and exit
the screen. The No button will cancel the abort process.
When the calibration is finished, the PID settings list will be
populated with suggested values and the four buttons underneath
will be enabled. The line above the PID settings list will read “Idle”
again as well.
The user has the option to select only one of these
sets of values: either the Under Damped set, the
Critically Damped set, the Over Damped set, or the
PI set. To select the set of values, press the
corresponding button. For example, to select the
Critically Damped set of values, press the Accept
Critically Damped button. The under damped
values will reach the setpoint faster, but there will be more overshoot involved. The over damped values
will work to minimize the overshoot, but it will be slower than the under damped values. The critically
damped values are considered the “optimum” values because they are a balance between the under
damped and over damped values with regards to time and overshoot. The PI values are just the
proportional band and the reset value (the P and the I from PID ). This could be applicable in an
atmosphere loop, where the rate won’t have much effect.
Once a set of values has been accepted, the user can press the Cancel button to exit the screen. The
accepted values can be viewed on the
PID Loop Setup menu option . Note: Once the screen is closed out,
the PID settings values will be lost . To populate these values again, another calibration routine will need to
be run.