Yaskawa MP900 Series Ladder Programming Manual - Manual (Page 216)

5.8 DDC Instructions
5.8.4 PI Control (PI)
5-147
Instructions
5
[ b ] Parameter Table Configuration for PI 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 output value (PI compensation) as shown below.
In the formula shown below, Yi’ is the previous I compensation of Yi and Ts is the scan time set value.
ΠWhen IRST (reset integration) is closed, the PI compensation is calculated with the I compensation set to 0.
P compensation = Upper/lower limit (UL or LL) of (Kp × X)
Yi (I compensation) = Upper/lower limit (IUL or ILL) of { (Ki × X + IREM) / + Yi’}
Y (PI compensation) = P compensation + Upper/lower limit (UL or LL) and Dead zone A (Width DB) of the I
compensation
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 Ki
Integral adjustment
gain
Gain for the input to the integral circuit IN
6 F Ti Integral time Integral time (s) IN
8 F IUL
Upper integration
limit
Upper limit for the I compensation IN
10 F ILL
Lower integration
limit
Lower limit for the I compensation IN
12 F UL PI upper limit Upper limit for the P + I compensation IN
14 F LL PI lower limit Lower limit for the P + I compensation IN
16 F DB PI output dead zone Dead zone width for the P + I compensation IN
18 F Y PI output PI compensation output (output to Out) OUT
20 F Yi I compensation I compensation storage OUT
Ti
Ts