Honeywell UDC3300 User Manual page 88

Setpoint Rate/Ramp/Soak Program Operation
SP Tuning After Start-Up
SP tuning will occur whenever the controller is in automatic mode and a setpoint
change occurs which is greater than the previously configured minimum setpoint
change value.
The controller will delay using any setpoint changes for 30 seconds to enable it to
calculate whether to SP tune or not. But if the controller is toggled between LSP1
and LSP2 or if any other key (such as LOWER DISPLAY) is pressed, the setpoint
change is immediate.
A large T is displayed in the upper display whenever tuning is in progress. During
this time, no changes to the configuration parameters, including the setpoint, are
permitted.
Aborting SP Tuning
If it is necessary to stop or abort the tuning:
Press the MANUAL/AUTO key to return to manual mode. This will cause an
immediate abort of tuning.
Disable SP or SP+PV in the Accutune Set Up group at function prompt
ACCUTUNE or ACCUTUN2.
Retuning
The controller will evaluate current tuning as SP changes occur. When retuning is
required, the controller operates in automatic mode and identifies new tuning
constants. At the point, the T appears and tuning values are entered and used until
retuning occurs again.
TUN+PV or SP+PV (Process Variable Disturbance)
The TUNE demand tuning or the SP tuning portions of these selections work as
stated previously.
During process variable (PV) disturbances which result from non-linearities, process
dynamics, load changes, or other operating conditions, PV adapt tuning will occur
whenever a PV disturbance of 0.3 % span or larger occurs. When this condition
exists, the controller monitors the process response to determine whether there has
been a true process change or a momentary upset. It will take 1 and 1/2 process
cycles around the setpoint before any process recognition can occur to an oscillating
process.
However, if no oscillation occurs, Adaptive may alter the parameters to speed up or
slow down the process response, if it determines the time to return to the SP is
excessive or too fast (overshoot occurs).
For this configuration, the controller operates with only one set of tuning parameters
for each loop. The second set, normally used for duplex output or for keyboard, PV
or SP switching, is not used because Adaptive tune continually updates the tuning
parameters based on the PV deviation.
78 UDC3300 Expanded Model: DC330E User Manual 5/00