12
- DRR227 -
User manual
7.4 Automatic Tuning
Automatic tuning procedure has been conceived to give user the possibility to have
a clear regulation also without knowledge of PID regulation algorithm. Setting
Auto
on parameter 8
P.i.d.
, the controller will check process oscillations and will modify PID
parameters.
7.5 Soft-Start
At starting the controller can follow a gradient expressed in units (ex. Degree/Hour) to
reach the setpoint.
Enter this gradient on parameter
21
SFt.G.
with the chosen units/hour
: at next activation
the controller will execute the Soft-Start function.
If parameter 24
S.tiM.
is different from 0,
after switch-on and elapsing of the time set
on parameter 24 , setpoint does not follow the gradient anymore, but it reaches final
setpoint with maximum power.
7.6 Automatic/Manual Regulation for % Output Control
This function allows to select automatic functioning or manual command of the output
percentage.
By parameter 69
Au.ma.
it is possible to select two modes.
1 First selection
(
en.
) pressing
SET
display 1 shows
p.---
, while on display 2 appears
auto.
Press to select
man
mode; it is now possible to modify the output percentage
using
and
. To back to automatic mode, using the same procedure, select
auto
on display 2:
MAN
led switches off and functioning backs to auomatic.
2
Second selection
(
en.st.
) enables the same functioning, but with two important
variants:
•
If there is a temporary power failure or after switch-off, manual functioning as well as the
previous output percentage value will be maintained at restarting.
•
If the sensor breaks during automatic functioning, controller moves to manual mode
while maintaining the output percentage command unchanged as generated by the PID
im
mediately before breakage.
Ex: on an extruder the resistance percentage command (load) is kept also in case of
input sensor failure.
7.7 Digital input functions
On DRR227
digital input can be enabled by parameter
25
dGt.i.
•
2.SPv.
: Switch between two setpoint thresholds: with digital input active DRR227
regulates on SET2, otherwise on SET1;
•
run.
: Regulation is enabled only with digital input active;
•
tune
: Enables/disables Tuning, if parameter 8
P.i.d.
is set on
man.
;
•
au.ma.
: (Automatic/Manual) if par. 19
au.ma.
is set on
en.
or
en.st.
, DRR227 regulates in
