Equivalent filter form – Galil DMC-2X00 User Manual
Page 200

The function G is equivalent to a digital filter of the form:
D(z) = 4KP + 4KD(1-z-1)
where
P
=
4
∗ KP
D
=
4
∗ KD ∗ T
and
4
∗ KD = D/T
Assuming a sampling period of T=1ms, the parameters of the digital filter are:
KP = 20.6
KD
=
68.6
The DMC-2x00 can be programmed with the instruction:
KP
20.6
KD
68.6
In a similar manner, other filters can be programmed. The procedure is simplified by the following
table, which summarizes the relationship between the various filters.
Equivalent Filter Form
DMC-2x00
Digital
D(z)
=[K(z-A/z) + Cz/(z-1)]
∗ (1-B)/(Z-B)
Digital
D(z) = [4 KP + 4 KD(1-z-1) + KI/2(1-z-1)]
∗(1-B)/(Z-B)
KP, KD, KI, PL K = (KP + KD)
⋅
4
A
=
KD/(KP+KD)
C = KI/2
B = PL
Continuous G(s)
=
(P + Ds + I/s)
∗ a/S+a
PID, T
P = 4 KP
D
=
4
T*KD
I = KI/2T
a = 1/T ln (1/PL)
190
• Chapter 10 Theory of Operation
DMC-2X00