Siemens 6DR2410, Manual

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Manual 1 Technical Description
1.5 Functional Description
1.5.8 Complex Functions (Arithmetic blocks c, d, h)
SIPART DR24 6DR2410
C79000-G7476-C153-03
79
The dead zone element lends the controller a progressive behavior, at small control dif-
ferences the gain is low or even 0, at larger control differences the specified kp is
reached. It should be taken into account that the remaining control difference can adopt
the value of the set response threshold AH. The factory setting of AH is 0 % and can be
set up to 10 % in the parameterization mode onPA.
In S-controllers the minimum necessary setting of AH is given by the minimum with
Δ
x =
ks ·
Δ
y and thus from the setting of tE. It can be increased to further calm the controlled
system. A low response threshold of about 0.5 % is recommended in K-controllers to
calm the control circuit and reduce wear on the actuator.
- Manipulated variable limiting yA, yE
The manipulated variable limiting with the YA and YE parameters is only effective in auto-
matic mode. The limits of these parameters are at --10 and +110 %. However, it should
be taken into account that the controllers neither output negative actuating currents nor
detect any negative position feedback signals.
If the manipulated variable y
a
reaches one of the limits YA or YE in automatic mode, fur-
ther integration is aborted to avoid integral saturation. This ensures that the manipulated
variable can be changed immediately after reversing the polarity.
In manual or follow--up mode the manipulated variable y can be driven out of the limit
range. When switching to automatic mode the last manipulated variable is transfered
bumplessly, then only changes in the manipulated variable in direction of the range YA to
YE are executed.
The manipulated variable limiting is only possible in K-controllers and three--position step
controllers with external position feedback.
- Bumpless switching to automatic mode
If there is no automatic operation (manual, tracking or active blocking operation, active
y = ya), the I part or the working point yo (only when Yo = Auto) is tracked so that switch-
over to automatic operation (active y = ya) is bumpless. Any still active D part is set to
zero.
y
I
or yo = ya -- kp · xd -- yz then ya = ya
- P--PI switching
With the control signal P = 1 the controller is switched over from Pi to P behavior, at Yo =
Auto the switchover by setting yo and yy
I
(t) is bumpless in both directions. If a fixed oper-
ating point yo is used, only switchover in direction of PI operation is bumpless.
- Parameter control, inputs h*.13, h*.14, h*.15
With the control inputs SG1, SG2, SG3 the parameters Kp, Tn, Tv can be changed by an
applied controlling variable.
The following applies: Kp = cP
⋅
SG1, Tn = tn
⋅
SG2, Tv = tv
⋅
SG3
The parameters kp, Tn, Tv gained in this way can be adjusted within the limits valid for
the parameters cP, tn, tv.
Typical controlling variables are the control difference xd (as an amount) for progressive
controls and x or y for working point dependent controls (unilinear control lines). In
addition it is possible to operate for example with great kp for startup procedures in P
operation (control signal P = 1) and to control with reduced Kp after switching over to PI
operation (control signal P = 0). The controlling variables can be switched over at the
same time as P switchover.