Panasonic FP7 Series Command Reference Manual page 496

10.12 EZPID (PID Operation: PWM Output Available)
■
Types of PID operation
Items
Reverse operation/
forward operation
Derivative-first PID
/Proportional-plus-
derivative-first PID
Auto-tuning
(Note 1) By default, controls are carried out in reverse operation, derivative-first. To change operation methods,
change values in the [S4+5] area before the second execution of EZPID instruction.
(Note 2) To execute auto-tuning, configure the setting in the area of control data [S1].
■
Setting of parameters [S1] to [S3]
Operand Parameter
name
[S1] Control data
10-46
Description
Select the upward/downward direction of output in the case of change to the process.
Specify "reverse operation" if output is increased when the process value decreases
(e.g. heating).
Specify "forward operation" if output is increased when the process value increases
(e.g. cooling).
Derivative-first PID: Usually, when the set point value is changed, the output variation
becomes larger but it converges faster.
Proportional-plus-derivative-first PID: Usually, when the set point value is changed, the
output variation becomes smaller but it converges slower.
By measuring process response, the respective optimal values for Kp, Ti and Td as PID
parameters are measured. When auto-tuning is executed, the estimated results are
reflected in the parameter area after auto-tuning is complete.
Setting Setting method
range
Bit 1 = 0
(ON):
Bit 0
Bit 0 = 0
(OFF):
When auto-tuning is completed correctly, bit 1 is set to 1 (ON).
Bit 1
Bit 1 is reset to 0 (OFF) at the start of instruction execution.
Specify whether the [S4] manipulated value (MV) should be cleared
when OFF is larger than ON in the execution condition for the
instruction.
Bit 2 Bit 2 = 0
(OFF):
Bit 2 = 1
(ON):
Select a method for outputting the result of PID operation.
Bit 3 = 0
Bit 3 (OFF):
Bit 3 = 1
(ON):
Specify the range (maximum value and minimum value) for internal
calculation of the manipulated value (MV).
Bit 4 = 0
Bit 4
(OFF):
Bit 4 = 1
(ON):
Bit F to Bit 5 Bits 5 to F are reserved bits. Use them as 0.
Auto-tuning request is issued. After auto-tuning is
completed, this is reset when the EZPID instruction is
executed. Reset this bit when auto-tuning is canceled.
PID operation is performed.
Clear the manipulated value (MV) at the time of
execution of the previous instruction.
Retain the manipulated value (MV) at the time of
execution of the previous instruction.
PWM output
Analog output
Use +20% and -20% of difference between the output
upper limit and the output lower limit
Use the output upper limit and the output lower limit
WUME-FP7CPUPGR-12