Setting measuring and control parameters
Parameter
Meaning
A
Dead zone
B
Output limit
P
Calculation of the proportion
IC
Calculation of the integral
DC
Calculation of the derivative
Xp
Reciprocal proportional value
Td
Time of the derivative
a
Control setpoint
x
Measured value
e
Control error
y
Control requirement
u
Metering control
Ti
Integral band
Xd
Dead band value around the setpoint
Td
Filter constant
Twu
Anti-saturation
108
Fig. 109: 'P.I.D.' metering mode
The difference between the setpoint w and the measured value x
corresponds to the control error, which is filtered by a dead zone.
The dead zone A eliminates small control errors. The filtered con‐
trol error is transmitted to the P.I.D. computer, which consists of
three components. Proportional (P), Integral (I) and Derivative (D).
The integral (in green) also has an anti-saturation system to limit
the effect of the integral.
The sum of the three components results in a control requirement
Y, which is limited depending on the actuators B you use (-100
% ... 0 %, or 0 % ... +100 %, or -100 % ... +100 %).
If the integral and the derivative are OFF, the metering mode is
[PROPORTIONAL] .
If only the derivative is OFF, the metering mode is
[PROPORTIONAL INTEGRAL] .
When all values are entered, the metering mode is
[PROPORTIONAL INTEGRAL DERIVATIVE] .
A3153