Yaskawa Ladder Works Programming Manual - Manual (Page 137)

7.6 PID CONTROL Instruction (PID)
7-16
Table of Real Type PID Instruction Parameters
ADR Type Symbol Name Specification I/O
0 W RLY Relay I/O Relay input, relay output * 1 IN/OUT
1 W － (Reserve) Reserve register －
2 F Kp P gain Gain of the P correction IN
4 F Ki I gain Gain of the integration circuit IN
6 F Kd D gain Gain of the differentiation circuit input IN
8 F Ti Integration time Integration time (s) IN
10 F Td1 Divergence
differentiation time
The differentiation time (s) used in the case of
diverging input. IN
12 F Td2 Convergence
differentiation time
The differentiation time (s) used in the case of
converging input. IN
14 F IUL Upper integration limit Upper limit for the I correction value IN
16 F ILL Lower integration limit Lower limit for the I correction value IN
18 F UL Upper PID limit Upper limit for the P+I+D correction value IN
20 F LL Lower PID limit Lower limit for the P+I+D correction value IN
22 F DB PID output dead band Width of the dead band for the P+I+D correction
value IN
24 F Y PID output PID correction output (also output to the A register) OUT
26 F Ti I correction value Storage of the I correction value OUT
28 F X Input value storage Storage of the present deviation input value OUT
*
1
:Relay I/O Bit Assignment
BIT Symbol Name Specification I/O
0 IRST Integration reset "ON" is input when integration is reset. IN
1 to 7 － (Reserve) Reserve relay for input IN
8 to F － (Reserve) Reserve relay for output OUT
Here, the PID operation is expressed as follows:
Y 1
X
Kp + Ki×
Ti×S
= Kd×Td×S
Y
X
= Kp＋Kd×Td×S
X : deviation input value
Y : output value
The following opertion is performed within the PID instruction:
Ti Td
Y = Kp×X +｛ ( Ki×X + IREM ) /
Ts
+ Yi'｝+ Kd× ( X – X' )×
Ts
X' : previous input value
Yi' : previous I output value
Ts : scan time set value