Operating Manual CMGZ432
20
Mathematic determination of control parameters
•
If the behaviour of the control loop is known, the control parameters may be
calculated by the known mathematical procedures and saved in the parameters
Proportional P0...P3
,
Integral I0...I3
resp.
Derivative D0...D3
. (There is only the
parameter set active which is chosen by the BCD inputs; refer to „9.7 Switching the
control parameters“.)
•
If the control loop is oscillating, the control parameters will be fine-tuned as described
under „Experimental determination of control parameters“.
Notice
There can be saved 4 different P-, I- and D- values (P0...P3; I0...I3; D0...D3). This allows
easy and flexible adjustment of the controller to different materials. (There is only the
parameter set active which is chosen by the BCD inputs; refer to „9.7 Switching the
control parameters“.) The instructions above is valid for all 4 sets of parameters. But for
better understanding, the instruction is written in common form.
Notice
Correct setting of the control loop can be difficult. To judge the adjustment of the control
parameters, an oscilloscope may be helpful to record the behaviour of the feedback value.
The oscilloscope shows if the control loop operates stable, and if there is no more static
error.
Notice
The controller must be adjusted so that the feedback reaches the reference in the shortest
possible way but without overshooting. If the feedback overshoots, this is seen on the
display or with an oscilloscope.
9.7 Switching the control parameters
There can be saved 4 different P-, I- and D- values (P0...P3; I0...I3; D0...D3). Due to that,
it is possible to adjust the control loop flexibly to different material characteristics.
However, switching to another set of parameters is only possible if the controller is
disabled.
Switching is done by using the digital inputs „BCD cipher 0“ and „BCD cipher 1“
according to table below:
dig. input
BCD cipher 1
dig. input
BCD cipher 0
Binary code
BCD code
Parameter
set
open
open
0 0
0
P0 / I0 / D0
open
24VDC
0 1
1
P1 / I1 / D1
24VDC
open
1 0
2
P2 / I2 / D2
24VDC
24VDC
1 1
3
P3 / I3 / D3
