Mitsubishi Electric MELSEC System Q, Special Instructions Manual

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6 PID CONTROL INSTRUCTION
6.2 PID Control Instruction (Exact Differential)
(s)+10 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.
(s)+11 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 0 (b0) 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.
Setting data for No. 2 loop (device: (s)+12 to (s)+21)
(s)+12 Operational
expression
selection The same as Setting data for No. 1 loop
(s)+13 Sampling cycle
(T
S
)
(s)+14 Proportional
constant (K
P
)
(s)+15 Integral constant
(T
I
)
(s)+16 Derivative constant
(T
D
)
(s)+17 Filter coefficient (

)
(s)+18 MV lower limit
(MVLL)
(s)+19 MV upper limit
(MVHL)
(s)+20 MV change rate
limit (

MVL)
(s)+21 PV change rate
limit (

PVL)
Setting data for No. n loop
Device Data item Description Setting range Setting
side Processing when the
setting data are outside
the setting range
With PID limits Without PID
limits