Delta AH500 - Page 339

Chapter 6 Applied Instructions
6-171
MV_MAX
：
Maximum output value
(MV_MAX)
Double word
MV_MIN
：
Minimum output value
(MV_MIN)
Double word
MOUT
：
Manual output value (MOUT) Double word
I_MV
：
Accumulated integral value
(I_MV)
Double word
MV
：
Output value (MV) Double word
Explanation:
1. The instruction is used to implement the PID algorithm. After the sampling time is reached, the
PID algorithm is implemented. PID stands for Proportional, Integral, Derivative. The PID
control is widely applied to mechanical equipments, pneumatic equipments, and electronic
equipments.
2. The setting of the parameters is as follows.
Device number
Data
type
Function
Setting
range
Description
PID_RUN
BOOL
Enabling the PID algorithm
True: The PID algorithm is
implemented.
False: The output value
(MV) is reset to 0,
and the PID
algorithm is not
implemented.
SV
REAL
SV
Range of
single-
precision
floating-
point
numbers
Target value
PV
REAL
PV
Range of
single-
precision
floating-
point
numbers
Process value
PID_MODE
Double
word/DINT
PID control mode
0: Automatic control
When PID_MAN is
switched from ON to OFF,
the output value (MV)
then is involved in the
automatic algorithm.
1: The parameters are tuned
automatically for the
temperature control.
When the tuning of the
parameters is complete,
the device is
automatically set to 0,
and is filled in with
appropriate parameters
K
P
, K
I
, and K
D
.
2: Automatic control
When PID_MAN is