Siemens SIMATIC S5-100U System Manual page 252

Integrated Blocks and Their Functions
Correction Rate Algorithm
The relevant correction increment dY
formula:
• Without feedforward control (D11.5=1); XW is forwarded to the differentiator (D11.1=0)
dY = K[(XW - XW ) R+TI
k k k-1
= K (dPW R + dI
k k
• With feedforward control (D11.5=0); XW is forwarded to the differentiator (D11.1=0)
dY = K[(XW - XW ) R+TI
k k k-1
= K (dPW R + dI
k k
• Without feedforward control (D11.5=1); XZ is forwarded to the differentiator (D11.1=1)
dY = K[(XW - XW ) R+TI
k k k-1
= K (dPW R + dI
k k
• With feedforward control (D11.5=0); XZ is forwarded to the differentiator (D11.1=1)
dY = K[(XW - XW ) R+TI
k k k-1
= K (dPW R + dI
k k
P element I element
When XW is applied:
k
When XZ is applied:
The result is:
Positioning Algorithm
The formula used to compute the correction rate algorithm is also used to compute the positioning
algorithm.
In contrast to the correction rate algorithm, however, the sum of all correction increments computed
(in DW 48), rather than the correction increment dY
9-18
is computed at instant t= k
k
XW + (TD (XW - 2XW
•
k k
+ dD )
k
XW + (TD (XW - 2XW
•
k k
+ dD )+dZ
k k
XW + (TD (XZ - 2XZ
•
k k
+ dD )
k
XW + (TD (XZ - 2XZ
•
k k
+ dD )+dZ
k k
D element
XW
k
PW
k
QW
k
PZ
k
QZ
k
dPW
k
dI
k
dD
k
dZ
k
TA according to the following
•
+ XW ) + dD )]
k-1 k-2 k-1
+ XW ) + dD )]+(Z
k-1 k-2 k-1
+ XZ ) + dD )]
k-1 k-2 k-1
+ XZ ) + dD )]+(Z
k-1 k-2 k-1
Z element k: k
= W - X
k k
= XW - XW
k k-1
= PW - PW
k k-1
= XW -2XW +XW
k k-1
= XZ - XZ
k k-1
= PZ - PZ
k k-1
= XZ -2XZ +XZ
k k-1
= (XW - XW )R
k k-1
= TI XW
•
k
= (TD QW +dD
•
k k-1
= (TD QZ +dD
•
k k-1
= Z - Z
k k-1
is output at sampling instant t
k
S5-100U
-Z )
k k-1
-Z )
k k-1
th
element
k-2
k-2
) when XW is applied
) when XZ is applied
.
k
EWA 4NEB 812 6120-02b