Pleiger Elektronik
GmbH & Co. KG
Edition: 6/2007 Subject to modifications
Manual for 362MC
Page: 41
Appendix C1:
Special function - Trend compensation
The standard software of the 362MC incorporates a special function for the enhanced control of systems
with large dead times. This special trend compensation function, a traditional feature of Pleiger
controllers, enables the differential activation of a second measuring sensor.
Differential adjustment of this measured value, applied to the controller, enables early adjustment of the
controller output, before the primary measuring sensor is able to detect the trend of the controlled
system as a system deviation - this detection being delayed as a result of the large dead time. The
expected trend of the controller output is thus compensated in advance.
Selection
The special trend compensation function is selected via the
Trend
parameter in the
commissioning menu Input
(5.6)
.
When the value
NC
is assigned to the Trend parameter, the special trend compensation function is
passive
.
D component (without trend compensation)
The
normal D component
of the standard controller
without trend compensation
is generated in
accordance with the diagrams shown here when
controller structure with D or D2 component is
selected in the
Struct
controller parameter.
When an input, such as the 2
nd
measured value input
PT100-2
is assigned to the
Trend
parameter,
however, the special trend compensation function is
active
.
The
D component
of the controller
with trend compensation
is generated in accordance with the
diagrams shown as follows when controller structure with D or D2 component is selected in the
Struct
controller parameter.
ActV X
Switching
output
or
Analogue
output
Setp W
dx
-
Out+Y
Out%Y
I-
controller
P-
controller
D-
controller
Actuator
Controlled
system
Feed Y
362MC
without trend compensation
(Structure with D)
in input menu:
ActValX
= PT100-1
Tend
= NC
Switching
output
or
Analogue
output
Setp W
dx
-
I-
controller
P-
controller
D2-
controller
362MC
(Structure with D2)
ActV X
