Siemens SIPART DR22 Manual page 100

1 Technical Description
1.5 Functional description of the structure switches
1.5.5 Control algorithm, parameter control, adaptation
y
x
x
M
Model curve x
-10 0
Start ID
ID fixed state
Start of adaptation
Figure 1-55 Time curve of an adaptation without error messages in which tU = 2×T95
Error checks are made during line identification in order to be able to prematurely abort the
identification. There are 13 control steps altogether which are displayed by flashing on the
digital x- and w- displays when errors occur. As soon as an error message appears, the line
identification is aborted and it must be restarted after correcting the presettings in the para-
meterization mode AdAP if necessary. Acknowledgement of the error messages,
see table 3-2 "Error messages of the adaptation procedure", page 177.
-- Controller design
The controller is designed according to the amount optimum method (S58=2). This setting
method is very robust and also allows variation of the line amplification. However, it gener-
ates an overshoot of approx. 5 % in the event of changes in the command variables. If this is
not wanted, you can also work with the controller design without overshoot (S58 = 1), Kp is
reduced here to 80 %.
The controller is designed for PI and PID behavior, therefore kp, tn and for PID tv are calcu-
lated, whereby the derivative action gain is fixed at 5. A prerequisite is that the D-element is
connected with xd or x (S55 = 0 or 1).
In S-controllers the response threshold AH is calculated in addition to kp, tn, tv. The parame-
ters tA, tE and tY must be set beforehand according to the actuating drives used (see chap-
ter 4.3, page 218). If the transient time T95 is near to 2 tY (floating time) overshooting may
also occur in controller designs with D-part at S58=1.
98
F(n,T)=min
M
50
x measuring
process
Δx = ks⋅Δy
67 % 100
Full scale
ID
Manual
Δy
y
manual
tU
%
tU
SIPART DR22 6DR2210
C79000-G7476-C154-03