Mitsubishi FX1S Series Programming Manual page 248

FX Series Programmable Controlers
PID setup parameters; S
The PID setup parameters are contained in a 25 register data stack. Some of these devices
require data input from the user, some are reserved for the internal operation and some return
output data from the PID operation.
Parameters S
Parame-
ter
name/function
S3 + P
Sampling time
S +0
3
Action - reaction
S +1
3
S +2
3
S +3
3
S +4
3
S +5
3
Derivative time
S +6
3
S +7 to
3
S +19
3
Process Value,
S +20
3
positive change
Process Value,
S +21
3
minimum value
Output Value,
S +22
3
positive change
Output Value,
S +23 maximum
3
negative change
S +24
3
See Initial values for PID loops for basic guidance on initial PID values; page 5-114.
See page 10-24 for additional parameters available with FX
3
+0 through S +6 must be set by the user.
3 3
Parameter
The time interval set between the reading the current
Process Value of the system (PV
T
S
b0
b1
direction and
alarm control
b2
b3 - 15
Input filter α
Alters the effect of the input filter.
This is a factor used to align the proportional output in a
Proportional
known magnitude to the change in the Process Value
gain K
P
(PV ). This is the P part of the PID loop.
nf
This is the I part of the PID loop.
This is the time taken for the corrective integral value to
Integral time
reach a magnitude equal to that applied by the
constant T
I
proportional or P part of the loop.
Selecting 0 (zero) for this parameter disables the I effect.
This is a factor used to align the derivative output in a
Derivative
known proportion to the change in the Process Value
gain K
D
(PV )
nf
This is the D part of the PID loop.
This is the time taken for the corrective derivative value to
reach a magnitude equal to that applied by the
constant T
D
proportional or P part of the loop.
Selecting 0 (zero) for this parameter disables the D effect.
Reserved for use for the internal processing
Active
maximum
when
S +1,
3
b1 is
set ON.
maximum
Active
when
S +1,
3
b2 is
set ON.
b0
b1
Alarm flags
b2
(Read Only)
b3
b4 - 15
Description
Forward operation(0),
Reverse operation (1)
Process Value (PV ) alarm enable, OFF(0)/
nf
ON(1)
Output Value (MV) alarm enable, OFF(0)/ON(1)
Reserved
This is a user defined maximum limit for the
Process Value (PV ). If the Process Value
nf
(PV ) exceeds the limit, S
nf
This is a user defined lower limit for the Process
Value. If the Process Value (PV
limit, S +24, bit b1 is set On.
3
This is a user defined maximum limit for the
quantity of positive change which can occur in
one PID scan. If the Output Value (MV) exceeds
this, S +24, bit b2 is set On.
3
This is a user defined maximum limit for the
quantity of negative change which can occur in
one PID scan. If the Output Value (MV) falls
below the lower limit, S
High limit exceeded in Process Value (PV
Below low limit for the Process Value (PV
Excessive positive change in Output Value (MV)
Excessive negative change in Output Value (MV)
Reserved
Applied Instructions 5
)
nf
+24, bit b0 is set On.
3
) falls below the
nf
+24, bit b3 is set On.
3
)
nf
)
nf
FX & FX MPUs.
2N, 2NC 1N
5-128
Setting
range
1 to 32767
msec
Not
applicable
0 to 99%
1 to
32767%
(0 to 32767)
x 100 msec
1 to 100%
(0 to 32767)
x 10 msec
0 to 32767
Not
applicable