Nivetec UNICONT PMM-500, User And Programming Manual

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10.4 A
UTO
-T
UNING
(AT) M
ODE
Automatic Tune Mode is selected when it is desired to use the Pre-tune and Self-tune facilities on a
controller to assist the user in setting up Proportional band, Integral and Derivative parameter values. Refer
to the following Automatic Tune Mode table.
Navigating in Automatic Tune Mode:
   +





Select Mode




Toggle to the
next setting
 
+
Return to
Select Mode
Entering unlock code
Default value: 0
Entering Auto Tuning
mode menu
Toggle
menu point
Toggle parameters
of Auto Tuning Mode

Caution:

Entering an incorrect unlock code will result to return to Select Mode.

If there is no key activity for 2 minutes the controller automatically returns to operator mode!
PARAMETER
SV-
DISPLAY
PV-DISPLAY ADJUSTMENT RANGE
DEFAULT
VALUE
PRE-Tune
Auto Pre-Tune ensures that
first approximation of the
PID values can be made.
Auto Pre-Tune feature is
activated on power up if

=

set.

OFF or ON
Indication remains OFF if Pre-Tune cannot be used at this time. This
applies if:
a). The setpoint is ramping
b). The process variable is less than 5% of span from the setpoint
c). The primary or secondary output proportional bands = 0
AT LED indicator flashes if PRE-Tune is ON OFF
SELF-Tune
Self-Tune continuously
optimises tuning while a
controller is operating

OFF or ON
Indication remains OFF if Self-Tune cannot be used at this time.
This applies if either proportional band = 0
AT LED indicator continuously lights if SELF-Tune is ON OFF
Approximation of the PID
values then continuous
optimising
PRE-Tune + SELF-Tune
ON

then


= ON

= ON
under

AT LED indicator flashes, then during

AT LED
continuously lights
OFF
Automatic tune mode lock
code

0 to 9999 0
10.5 M
ANUAL SETTING OF
PID
PARAMETERS
If Auto Tuning mode is not enabled, controlling can be manually tuned. Manual setting of PID parameters is
suitable only for processes that are not harmed by large fluctuations in the process variable. This technique
needs technical competence and practise in process controlling, therefore changing of the parameters are
allowed only if regulating system surely remains its safe operation.
All parameters should be set in Configuration and Set-up Modes before manual tuning of PID parameters!
Single Control Tuning (PID with Primary Output only) – cooling, or heating

In Configuration mode select Single control type
Primary control


 Select Setpoint Value in Operator Mode in accordance to the process.