Operating Manual CMGZ433
25
9.12
Additional settings
PI or PID configuration
The Tension Controller can be operated as PI or as PID controller. FMS recommends
operating as PI controller because this setup is much easier to handle, and the controller
dynamics are sufficient for most applications (refer also to „5. Controller theory“):
Characteristics of PI controller
Characteristics of PID controller
+
Easier to adjust than a PID controller
+
Quite good behaviour
+
Is very suitable where great inertia moments
make the D component ineffective
+
Behaviour is more dynamically than that of
a PI controller (PID controller are used
where the dynamics of a PI controller is not
enough)
−
The D component causes greater tendency to
instable behaviour than using a PI controller!
The parameter
PID-configuration
is set to
PI
or
PID
, depending on required operation
mode.
Automatic start function
With the integrated automatic start function, it is possible to start very carefully even if
the material has some slack, because the controller operates with only a small start speed
until a certain minimum tension value is reached. After reaching the minimum tension,
controlling will be fully activated.
To enable automatic start function, the parameters
Start speed
and
Limit speed
are set to
appropriate values (ref. to „11. Parametrization“).
Setting of the lowpass filters
The control unit provides 3 lowpass filters independently adjustable from each other.
They are used to prevent noise which is added to the signals. Signal variations which are
faster than the cut-off frequency are then suppressed. The lower the cut-off frequency, the
more sluggish the output signal will be.
The lowpass filters are configured by setting its cut-off frequency to an appropriate value.
The cut-off frequency is set in the parameter
Lowpass output, Lowpass instrument
resp.
Lowpass display
(ref. to „11. Parametrisation“).
Notice
If the cut-off frequency is set to a value too low, the output signal will become sluggish.
It may be that the feedback value is no longer suitable for control loop applications. You
have to pay attention that the cut-off frequency is set to a suitable value.
Setting of the limit switches
The control unit provides 2 limit switches which can be tapped at the digital outputs
(terminals b14 and b16 resp. 29 and 30). The limit switches are actuated when the
feedback value exceeds resp. undershoots (depending on parameter
Limit 1 min / max
resp.
Limit 2 min / max
) the force values stored in parameters
Limit value 1
resp.
Limit
value 2
.
Tapping of the limit switches is done according to wiring diagram (fig. 6 or 7).
Scaling of the feedback output (instrument output)
With default setting, the feedback output gives the maximum signal (10V) when the
nominal force of the sensors is reached. The output signal level can be customized with
the parameter
Scale instrument
.
Содержание CMGZ433 Series
Страница 45: ...Operating Manual CMGZ433 45...
