West Control Solutions KS 42-1 - Manual (Page 18)

The control parameters can be determined from the values calculated for delay
time T
u
, maximum rate of increase v
max
, control range X
h
and characteristic K ac-
cording to the formulas given below. Increase Xp, if line-out to the set-point os-
cillates.
3.7 Alarm handling
Max. three alarms can be configured and assigned to the individual outputs. Ge-
nerally, outputs
OuT.1... OuT.3 can be used each for alarm signalling. If more
than one signal is linked to one output the signals are OR linked. Each of the 3 li-
mit values
Lim.1 … Lim.3 has 2 trigger points H.x (Max) and L.x (Min), which
can be switched off individually (parameter = “ OFF”). Switching difference
HYS.x of each limit value is adjustable.
Operation
Alarm handling 18 Operating KS4x-1
Formulas
K = Vmax * Tu controller behavior Pb1 [phy. units] td1 [s] ti1 [s]
With 2-point and
3-point controllers,
the cycle time must be
adjusted to
t1 / t2 £ 0,25 * Tu
PID 1,7 * K 2 * Tu 2 * Tu
PD 0,5 * K Tu OFF
PI 2,6 * K OFF 6 * Tu
P K OFF OFF
3-point-stepping 1,7 * K Tu 2 * Tu
Parameter adjustment effects
Parameter Control Line-out of disturbances Start-up behaviour
Pb1 higher increased damping slower line-out slower reduction of duty cycle
lower reduced damping faster line-out faster reduction of duty cycle
td1 higher reduced damping faster response to disturbances faster reduction of duty cycle
lower increased damping slower response to disturbances slower reduction of duty cycle
ti1 higher increased damping slower line-out slower reduction of duty cycle
lower reduced damping faster line-out faster reduction of duty cycle