Page 14 of 24 M6493 Issue 10.3
Start Auto-tuning.
7.10.2. During normal operation, keep buttons
and
pressed for
3 seconds.1CT blinks on the display. With
+
or
pressed set the cycle time in order to define the dynamic process to be
controlled. To abort the auto-tuning function, press
; to start auto-
tuning press
+
or wait or 30 seconds.
During Auto-tuning.
During the entire auto-tuning phase, the display alternates TUN with the actual
temperature being measured. In case of power failure, when power is restore,
after the initial auto-test phase, the controller resumes the auto-tune function.
To abort the auto-tuning, without modifying the previous control parameters,
keep button
pressed for 3 seconds. After auto-tuning has successfully
taken place the controller updates the control parameters and starts to control.
Errors
If the auto-tuning function failed, the display shows an error code:
•
E1 time out 1 error: the controller could not bring the temperature within the
proportional band. Increase 1SP the case of the heating control, vice versa,
decrease 1SP in the case of refrigeration control and re-start the process.
•
E2 timeout2 error: the auto-tuning has not ended within the maximum time
allowed (1000 cycles). Re-start the auto-tuning process and set a longer
cycle time 1CT.
•
E3 temperature over-range: check the error was not caused by a probe
malfunction, then decrease 1SP in the case of heating control or increase
1SP in the case of refrigeration control and then restart the process.
•
To eliminate the error indication and return to the normal mode, press the
button
.
Control improvement.
•
To reduce overshoot, reduce the integral reaction reset 1AR
•
To increase the response speed of the system, reduce the proportional band
1PB. Caution: doing this can make the system less stable.
•
To reduce swings in steady-state temperature, increase the integral action
time1IT; system stability is thus increased, although it’s response speed is
decreased.
•
To increase the speed of the response to the variations in temperature,
increase the derivative action time1DT. Caution: a high value makes the
system sensitive to small variations and it may be a source of instability.