Honeywell 900 User Manual page 166

Loops
Loop Setup
Item
Duplex Tuning
SP Step Change
SP Tune Step Direction
Process Gain
Start Tune
154
Selection of three tuning actions when performing a Cycle Tuning procedure on a
Duplex control loop.
DISABLE - Duplex type tuning is disabled and simplex type tuning is used instead.
The resultant is blended tuning which is derived from the process response to
cycling the output between the low and the high output limits. The calculated tuning
parameter values are stored for each side.
MANUAL - Tuning must be initiated manually for each side. The current LSP or RSP
value is used as the target SP for the desired heat or cool side tuning. For the heat
side, the output cycles between 50 percent and the high output limit and for the cool
side the output cycles between 50 percent and the low output limit. Tuning values
are calculated and stored only for the side tuned.
AUTOMATIC - Heat and Cool tuning are sequentially performed automatically.
During the operation of this tuning the target SP used is the mid point between the
high output limit and 50 percent for the heat side and the low output limit and 50
percent for the cool side. During tuning for each side the cycling of the output results
in the PV oscillating around the target SP value. From the data gathered during the
oscillations, tuning values are calculated and stored for each side. After tuning on
both sides is completed, the process SP is returned to the value of the last SP used
prior to the initiation of the tuning procedure.
Configuration parameter for Setpoint Tuning. Select a value between 5 and 15%.
This defines the value of the initial Setpoint step change that is used as the target
Setpoint value for process identification.
Configuration parameter for Setpoint Tuning. The selection of UP or DOWN results
in the Setpoint change value added to or subtracted from the present Setpoint value.
Configuration parameter for Setpoint Tuning. Gain identification value for the
process. Select a value between 0.10 and 10.0. Normal value is 1. This value is
used to estimate the size of the initial output step for a Setpoint Tune.
Select this to begin the Accutune III process.
900 Control Station User Guide
Description
Revision 9
May 2014