User`s manual

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MELSEC-Q
2 STRUCTURE AND COMBINATIONS OF PROCESS CONTROL
INSTRUCTIONS
2.2.8 Index qualification
Index qualification usable with the process control instructions is the same as the one usable with
the basic instructions of the QnPHCPU.
2.3 Basic Loop Types Available by Combinations of Process Control
Instructions
Loop type Structure Application
S.IN
INPUT OUTPUT
S.PHPL
S.2PID S.OUT1
SET
PV
SV
MV
2-degree-of-freedom PID control
(S2PID)
S.IN
INPUT OUTPUT
S.PHPL S.2PID
S.DUTY
SET
PV
SV
MV
Used for general PID control (2-degree-of-
freedom). (velocity type)
Conducts PID operations for each control
cycle.
S.IN
INPUT OUTPUT
S.PHPL S.PID S.OUT1
SET
PV
SV
MV
PID control
(SPID)
S.IN
INPUT OUTPUT
S.PHPL S.PID S.DUTY
SET
PV
SV
MV
Used for general PID control. (velocity
type)
Conducts PID operations for each control
cycle.
PIDP control
(SPIDP)
S.IN
INPUT OUTPUT
S.PHPL S.PIDP
SET
PV
SV
MV
Used for general PID control. (Position
type)
Conducts PID operation for each control
cycle.
Sample PI control
(SSPI)
S.IN
INPUT OUTPUT
S.PHPL S.SPI S.OUT1
SET
PV
SV
MV
Used for a process that has long dead
time.
PI control is executed for only the period of
control execution time in each control
cycle and the output is kept constant after
that.
I-PD control
(SIPD)
S.IN
INPUT OUTPUT
S.PHPL S.IPD S.OUT1
SET
PV
SV
MV
Used to make slow response so that the
operation end and process are not given
impact when the set value is varied.
Blend PI control
(SBPI)
S.IN
INPUT OUTPUT
S.PHPL S.BPI S.OUT1
SET
PV
SV
MV
Used for a process where the manipulated
value may vary in a short period of time
and may be constant in a long period of
time.
Rate control
(SR)
S.IN
INPUT1 OUTPUT
S.PHPL S.R S.OUT2
SET
PV
SV
MV
Control is performed to keep constant the
rate of the given manipulated value to the
other varying value.
2-position ON/OFF control
(SONF2)
S.IN
INPUT OUTPUT
S.PHPL S.ONF2
SET
PV
SV MV
Depending on the sign (positive/negative)
of a deviation, operation to turn the
manipulated value ON or OFF is
performed.
3-position ON/OFF control
(SONF3)
S.IN
INPUT OUTPUT
S.PHPL S.ONF3
SET
PV
SV MV
3-position ON/OFF control outputs signals
of three areas in response to the process
value to carry out control.
This control can suppress the sudden
variation of the manipulated value.