
12 - ATR227 - 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 Au to 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 . ti M . is dierent from 0, after switch-on and elapsing of the time set
on parameter 24 , setpoint does not follow the gradient anymore, but it reaches nal
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
c
to select man
mode; it is now possible to modify the output percentage
using
c
and
d
. To back to automatic mode, using the same procedure, select auto
on display 2: MAN led switches o 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-o, 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
immediately 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 ATR227 digital input can be enabled by parameter 25 d G t .i .
• 2.SPv .: Switch between two setpoint thresholds: with digital input active ATR226
regulates on SET2, otherwise on SET1;
• ru n .: 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., ATR227 regulates
in manual mode if digital input active, otherwise the regulation is automatic..
• Act. t.: (Action Type) heating regulation with inactive digital input; Cooling
regulation with active digital input;
• o . rSt: (Outputs Reset) allows to reset the outputs if Manual reset should be
congured for command output and/or alarm outputs.