Yaskawa MP900 Series Ladder Programming Manual - Manual (Page 221)

5.8 DDC Instructions
5.8.5 PD Control (PD)
5-152
[ b ] Parameter Table Configuration for PD Instruction with Real Numbers
∗ The relay input and output bit assignments are the same as for integers.
[ c ] Internal Operation of the Instruction
The deviation X input is used to calculate the PD compensation output as shown below.
In the formula shown below, X’ is the previous input value of X, Ts is the scan time set value, and Td* is the differen-
tial time.
∗ The differential time (Td) is Td1 when X – X’ and X’ have the same sign, and Td2 when X – X’ and X’ have dif-
ferent signs.
P compensation = Upper/lower limit (UL or LL) of (Kp × X)
D compensation = Kd × (X – X’) × Upper/lower limit (IUL or ILL) of
PD compensation = Upper/lower limit (UL or LL) of (P compensation + D compensation) and Dead zone A
(Width DB)
Address
Data
Type
Symbol Name Specification I/O
0 W RLY Relay I/O Relay inputs and relay outputs * IN/OUT
1 W – (Reserved.) Spare register –
2 F Kp P gain Gain for the P compensation IN
4 F Kd D gain Gain for the input to the differential circuit IN
6 F Td1
Differential time for
divergence
Differential time used when the input diverges (s) IN
8 F Td2
Differential time for
convergence
Differential time used when the input converges (s) IN
10 F UL PD upper limit Upper limit for the P + D compensation IN
12 F LL PD lower limit Lower limit for the P + D compensation IN
14 F DB PD output dead zone Dead zone width for the P + D compensation IN
16 F Y PD output PD compensation output (output to Out) OUT
18 F X Input value storage Storage of current input value OUT
Td
Ts