Autotune; Tune Program - CAL Controls 3300 Operating Manual

Select the most appropriate method of Autotune , Tune or
Tune at Setpoint, to suit the application.
Note: The proportional cycle-time can be pre-selected
before starting Autotune, see PROPORTIONAL
CYCLE-TIME.
The TUNE program should be run with the load cool. The
output is cycled at 75% of the setpoint value to avoid any
overshoot during the tuning cycle. The warm-up
characteristics are monitored and set DAC which minimises
overshoot on subsequent warm-ups.
The TUNE AT SETPOINT program is recommended:
when the setpoint is below 100°C/200°F, where
TUNE's tuning cycle at 75% setpoint may be too
close to ambient to produce good results;
when the process is already hot and the cooling
rate is slow;
when controlling multi-zone or heat-cool
applications;
to re-tune if the setpoint is changed substantially
from previous Autotune.
Note: dAC is not re-tuned by TUNE AT SETPOINT.

TUNE PROGRAM

Temp
Setpoint
Tuning DAC
TUNE
Cycle
75% SP
1
1 / on/off tuning
4
cycles
Start
TUNE
Enter program mode and select
The controller will alternately display
Press and hold and press
The controller will alternately display
Exit program mode.
The TUNE program will now start. The controller will
alternately display
TUNE
as it climbs to setpoint.
Note: During tuning, the main setpoint (SP1) LED will flash.

AUTOTUNE

PID
New PID
values
entered
Time
(100% output)
TUNE
and oFF .
TUNE
once,
and on .
TUNE
and the process temperature
7