West Control Solutions KS98-1 - Manual (Page 257)

Further status displays on the operating page
During optimization or with cascade control, further display elements may appear on the operating page.
Statuses during optimization
The optimization statuses are displayed with priority in the display field for manual operation.
Optimization running: display: Orun
Faulty optimization: display: Oerr
When the optimization is finished with an error, the unit waits for
acknowledgement by the operator.
By pressing key H twice or by input of the stop command on the
optimization page, the controller returns to the initial status.
Cascade control operation
The cascade is one of most frequent controller structures with cou-
pled control loops.
To facilitate construction and handling of these cascades, measu-
res for connection and operation were taken at and in the controller blocks.
w A cascade consists of min. two controllers: a master controller the process value of which provides the main cor -
recting variable and a slave controller on the process value of which the main variable is dependent.
w For building a cascade, the correcting variable output ( Yout1) of the master may be wired to the input
(( Wext) of the slave controller via a scaling function (SCAL).
w The slave controller is informed on the cascade by connecting the master block number output to the slave cas -
cade input.
+ The special operating functions of a controller cascade for master and slave are grouped on the common operating
page of the slave controller.
Ü Title of the operating page
* Parameter set selection, if available
Ö Cascade mode toggle field (open/close)
ä Master source (W
int
, W
ext
, W
2
)
# Display field for manual mode (otherwise empty)
< Physical unit (master or slave)
> Entry into self-tuning
y Master
x Slave process value
c (from master during automatic mode, from slave
with open cascade)
v Bargraph and display
(Y from slave or X/XW from master)
— Display of slave selection with open cascade (ot-
herwise empty)
9499-040-82711
Controller applications: III-257
Fig.:72 Reglerseite bei gestarteter
Optimierung.
Ь
*
Ц
д
#
<
y
>
c
v
x
b
Fig. 73 Operating page of a cascade controller
in automatic mode