Autotune
AUTOTUNE
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
Enter program mode and select
TUNE
The controller will alternately display
TUNE
and
oFF
.
Press and hold
✱
and press
▲
once,
The controller will alternately display
TUNE
and
on
.
Exit program mode.
The
TUNE
program will now start. The controller will
alternately display
TUNE
and the process temperature
as it climbs to setpoint.
Note:
During tuning, the main setpoint (SP1) LED will flash.
Temp
Setpoint
Cycle
75% SP
Start
TUNE
TUNE
Tuning
DAC
PID
1
1
/
4
on/off tuning
cycles
New PID
values
entered
Time
(100% output)
7
