Three-State Controller - Pid; Three-State Controller - Fuzzy, Afuza, Afuzs - Ecolab MULTRONIC Notice Technique

8.4.1

Three-state controller - PID

The PID controller should be given preference if optimised PID parameters are available or the
fuzzy controller is not exact or fast enough.
Control is by means of a P, PI, PD or PID action (see chapter 8.6). The internally calculated
variable causes the outputs to switch on and off. The software has incorporated a switching
hysteresis of 1% in order to prevent the output from switching wildly backwards and forwards
around the setpoint. This hysteresis is permanently programmed and cannot be changed.
The three-state controller thus requires two outputs; these are installed in the unit as a
standard feature.
Parameters
Setpoint (W):
Proportional area (XP1):
Proportional area (XP2):
prelim time (T v ):
delay time (T n ):
ON period (T min ):
Setpoint-difference (XSH):
8.4.2

Three-state controller - Fuzzy, aFUZa, aFUZs

For the standard fuzzy controller only the setpoint value (W) and the approximate down time
need be entered. The fuzzy controller reacts immediately to events and offers a high level of
precision in the setpoint value range.
Both adaptive fuzzy controllers aFUZa and aFUZs adapt automatically to the process. The
adaptive fuzzy controller aFUZa has an algorithm for asymptomatic approximation of the
setpoint value. The adaptive fuzzy controller aFUZs is optimised for rapid approximation of the
setpoint value while accepting over-oscillation.
Control is by means of a so-called 'fuzzy algorithm'. The controller clocks.
Parameters
Setpoint (W):
Delay time:
Setpoint difference (XSH):
417101163_Multronic.doc
Setpoint value within the measuring range
(including switching point 1)
PID-action (see chapter 8.6)
Set internally and permanently to 0.5 seconds.
Distance (in %) between switching point 2 and
setpoint value.
Setpoint value within the measuring range (including
switching point 1)
Modification of the actual value by a certain range. (does
not apply to adaptive fuzzy controllers aFUZa and aFUZs)
Distance (in %) between switching point 2 and setpoint
value.
- 64 - Rev: 5.07-08