Mitsubishi QCPU, Structured Programming Manual

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5.5 PID Control Instruction (Inexact Differential)
5.5.4 PIDPRMW instruction
5-171
5
QCP
U
IN
S
T
RUCTI
O
N
DE
TA
IL
S
S_PI
DPRMW
S_PIDPRMW
Device Data item Description
Setting range
Setting
side
Processing when the
setting data are outside the
setting range
With PID limits
Without PID
limits
+8
MV change rate
limit
( MVL)
Set the variation limit
between the previous
MV and the present MV.
When the MV variation is
greater than the limit
value, bit 1 (b1) of the
alarm device is set to '1'.
MV variation is not
limited. (Even if the MV
variation exceeds the
limit value, the actual MV
variation is used as it is
for calculating the MV.)
0 to 2000
-32768 to
32767
User
In the case of "With PID
limits", the PID operation is
performed after values are
replaced as follows:
• If the MVL value is
less than 0, the value is
clipped to
0.
• If the MVL value is
greater than 2000, the
value is clipped to
2000.
+9
PV change rate
limit
( PVL)
Set the variation limit
between the previous PV
and the present PV.
When the PV variation is
greater than the limit
value, bit 1 (b1) of the
alarm device is set to '1'.
PV variation is not
limited. (Even if the PV
variation exceeds the
limit value, the actual PV
variation is used as it is
for performing the PID
operation.)
0 to 2000
-32768 to
32767
User
In the case of "With PID
limits", the PID operation is
performed after values are
replaced as follows:
• If the PVL value is
less than 0, the value is
clipped to
0.
• If the PVL value is
greater than 2000, the
value is clipped to
2000.
+10
(Fixed value)
–
0 0 User
–
+11
Derivative gain
(K
D
)
Set a duration (delay in
action) for derivative
action.
As the setting value
increases, the duration
becomes smaller and
action becomes closer to
exact
differential.
Ideal value K
D
= 8.00
0 to 32767
(unit: 0.01)
If setting value >
30000
K
D
= Infinite
( )
0 to 32767
(unit: 0.01)
If setting value >
30000
K
D
= Infinite
( )
User
An error occurs and the PID
operation for the
corresponding loop is not
performed.
+12
(Fixed value)
–
0 0 User
–
+13
(Fixed value)
–
0 0 User
–
S
S
S
S
S
S