Siemens SIPART DR22 Manual page 94

1 Technical Description
1.5 Functional description of the structure switches
1.5.5 Control algorithm, parameter control, adaptation
Controller direction of effect
The controller direction of effect is set with S54 (controller I) or S56 (controller II), it must
always have an opposite behavior (reverse coupling) to the controlled system (including
actuator and transmitter)
S54/56= 0, normally acting controller (+Kp, rising x causes falling y) for normally acting systems
(rising y causes rising x)
S54/56=1, reversing controller (--Kp, rising x causes rising y) for reversing systems (rising y
causes falling x).
Operating point yo for P-controller
-- The operating point yo of the P-controller can be set either automatically or as a parameter
(onPA).
-- Automatic operating point (Yo = Auto)
Whenever there is no automatic operation (manual, follow-up, safety or blocking operation)
the operating point yo is followed up so that switching to automatic operation is bumpless.
This gives an automatic setting of the operating point yo in manual mode:
yo = y  K (w--x
H p H
yo = y  K (w--x
H p H
If the actual value in manual mode (x
ate manual manipulated variable (y
nipulated variable (y
yo = y or yo = y
c6⋅z
H H
-- Set operating point (Yo = 0 to 100 %)
-- The controller operates in all operating modes with the operating point set as a permanent
parameter.
Bumpless switching to automatic mode
If there is no automatic operation (manual, follow-up, safety or active blocking operation) the
I-part or the operating point yo (only at Yo = Auto) is followed up so that the switching to auto-
matic operation is bumpless. Any still active D part is set to zero.
P-PI switching
With the control signal P*=1 the controller is switched from Pi to P-behavior, at Yo=Auto the
switching is bumpless.
92
)c6⋅z II in controller II or
y
)c6⋅z in controller I
y
) is driven to the desired setpoint (w) by the appropri-
H
), the operating point (yo) is identical to the manual ma-
H
).
H
.
y
Manual
SIPART DR22 6DR2210
C79000-G7476-C154-03