Operand Parameter name Default Setting range Setting method
reaches 80% of the set point value (SP). Once the
80% is exceeded, PID control is initiated. If the set
point value is K0 (default), PID control is executed
from the beginning.
[S4+4]
Control interval
(Ts)
U100
(1s)
U1 to U6000
(0.01 to 60.0 s)
Specify the interval to execute PID operation.
The setting value × 0.01 is the actual control interval.
[S4+5] Control mode
U0
(Derivati
ve-first,
reverse
operatio
n)
U0 to U3
U0: Derivative-first, reverse operation
U1: Derivative-first, forward operation
U2: Proportional-plus-derivative-first, reverse
operation
U3: Proportional-plus-derivative-first, forward
operation
[S4+6]
Auto-tuning bias
value
U0 U0
In order to control overheating during auto-tuning,
specify difference between the set point value during
auto-tuning and the actual set point value.
(Note 3)
[S4+7]
Auto-tuning
Proportional gain
(Kp)
Correction
coefficient
U125
(125%)
U50 to U500
(50 to 500%)
By setting coefficients listed on the left and
executing auto-tuning, parameter values obtained
through auto-tuning are multiplied by the respective
coefficients, and stored in the parameter setting
areas [S3+1] through [S3+3].
Example) If U200 is set to [S4+7], the value given as
200% of the proportional gain Kp, obtained through
auto-tuning, is set to [S3+1].
[S4+8]
Auto-tuning
Integral time (Ti)
Correction
coefficient
U200
(200%)
U50 to U500
(50 to 500%)
[S4+9]
Auto-tuning
Derivative Time
(Td)
Correction
coefficient
U100
(100%)
U50 to U500
(50 to 500%)
[S4+10]
Auto-tuning
progress status
U0 U0 to U5
This indicates the progress of auto-tuning. Starting
with the default [0], a value between U1 and U5 is
stored in accordance with the progress. After auto-
tuning is completed, the value returns to U0.
[S4+11] to
[S4+29]
Work area for
PID operation
K0 -
This work area is used by the system program for
operation. Ensure that this is not overwritten by your
program.
(Note 1) By default, the [S4] manipulated value (MV) is cleared when the EZPID instruction is started up. If it is
necessary to retain the value from the previous execution, set 1 to bit 2 of the operand [S1] before
execution of the EZPID instruction.
(Note 2) The areas [S4+1] through [S4+29] should be preset to default when the EZPID instruction is started
up.
(Note 3) For details of the auto-tuning bias value, see ""Setting of auto-tuning bias value [S4+6]"".
■
Sample program (PWM output)
● In this sample, PWM output by PID operation is carried out after setting proportional gain
(Kp), integral time (Ti), and derivative time (Td) through auto-tuning.
10.12 EZPID (PID Operation: PWM Output Available)
10-48 WUME-FP7CPUPGR-12
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