Siemens 6DR2410, Manual

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1 Technical Description
1.5 Functional Description
1.5.8 Complex Functions (Arithmetic blocks c, d, h)
Manual
86
SIPART DR24 6DR2410
C79000-G7476-C153-03
In controlled systems of the 1st order a PI or PID controller design, in systems of the 2nd
order a PID controller design cannot be implemented according to an amount optimum
because in these cases kp goes to
1
. A controller design is produced in which the ratio
of the line time constant to control loop constant is 6.
At the end of adaptation the previously active parameters (identification by .o) and the
newly determined parameters (identification by .n) can be read in the parameterization
mode AdAP. The new parameters for PI-controllers and for PID-controllers are offered.
In addition the determined line order 1 to 8 is displayed as a suffix to the Pi or Pid identifi-
cation.
The selected parameters **.0, **.n Pi.* or **.n Pid.* (** = parameter name, * = line order 1
to 8) can be changed and accepted optionally.
The operating technique of the adaptation procedure is described in chapter 3.3.2.
D
Adaptation of the S--controller to the actuating drive
- internal position feedback
The actuating time of the actuating drive is set with the online parameter tY
(10 to 1000 s); the factory setting is 60 s.
The online parameter tE should be selected at least great enough that the actuating drive
starts moving reliably under consideration of the power switches connected before it. The
greater the value of tE, the more resistant to wear and more gentle the switching and
drive elements connected after the controller operate. Large values of tE require a
greater dead band AH in which the controller cannot control defined because the resolu-
tion of the controlled variable diminishes with increasing turn--on duration.
The factory setting is 180 ms for tE. This corresponds to a y resolution in a 60 s actuating
drive of:
Δ
y
=
100 % · tE
tY
=
100 % · 180 ms
60 s
=
0, 3 %
The minimum possible resolution is transposed with the line amplification Ks to the con-
trolled variable:
Δ
x = K
s
⋅
Δ
y
The parameter tA (minimum turn--off time) should be chosen at least great enough that
the actuating drive is safely disconnected under consideration of the power switches con-
nected before it before a new pulse appears (especially in the opposite direction). The
greater the value of tA, the more resistant to wear the switching and drive elements con-
nected after the controller operate and the greater the dead time of the controller under
some circumstances. The value of tA is usually set identical to the value of tE.
tA = tE = 120 to 240 ms are recommended for 60 s actuating drives. The more restless
the controlled system, the greater the two parameters should be selected if this is rea-
sonably justified by the controller result.
The response threshold AH must be set according to the set tE and the resulting
Δ
y or
Δ
x. The condition
AH
>
Δ
x
2
or AH
>
K
s
· tE · 100 %
2 · tY