
28
GOSSEN METRAWATT GMBH
Manual Self-Tuning
Parameters
Pb 1
,
Pb11
,
tu
and
tc
are determined by means of manual
self-tuning in order to maintain optimized controller dynamics. An actua-
tion test or an oscillation test is performed to this end.
Preparation
–
Complete configuration
parameter settings
(page 24) must first be entered for use of the con-
troller.
–
The actuators should be deactivated with the
off / manual operation
–
A
recorder
must be connected to the sensor and adjusted appropriately to prevailing circuit dynamics and
the setpoint.
In the case of differential controllers, the actual value difference must be recorded.
–
For 3-step or split range controllers, on and off-time must be recorded for switching output I or the contin-
uous output (e.g. with an additional recorder channel or a stopwatch).
–
Configure as
limit transducer
(controller sort = 0).
–
Set read-out cycle time to the minimum value:
tc
=
0.5
.
–
If possible, deactivate manipulating factor limiting.
YH
=
100
.
–
Reduce (or increase) the
setpoint
so that overshooting and undershooting do not cause any impermissible
values.
Performing the Actuation Test
–
dbnd
=
MR
Setting for 3-step and split range controllers (switching output II may not be triggered)
dbnd
=
0
Setting for step-action controllers (switching output II must be triggered)
–
Start the recorder.
–
Activate the actuators with
automatic operation
.
–
Record two overshoots and two undershoots.
The actuation test is now complete for 2-step, continuous-action and step-action controllers.
Continue as follows for 3-step and split range controllers:
–
Set
dbnd
to
0
in order to cause further overshooting with active switching output II. Record two over-
shoots and two undershoots.
–
Record
on-time T
I
and
off-time T
II
at switching output I or the continuous output for the last oscillation.