Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1245

■Set value
The set value (E2) is valid only when b0 of the set value pattern (SVPTN) is set to 0 (Used). To use the upper loop MV as the
set value (E2), specify the device (offset +12) where the manipulated value (MV) of the upper loop is set.
If E2 is not used, specify a dummy device (SD820).
Operand: (s3)
Position Symbol Name
+0 E2 Set value
+1
■Execution cycle (T)
Set the execution cycle (T) in SD816 and SD817 in single-precision real number.
Processing details
This instruction performs two-degree-of-freedom PID control operation when the specified control cycle is reached.
At this time, the instruction also performs the following processing steps: SV setting, tracking, gain (Kp) operation, and
deviation check.
The following is the processing block diagram of the S.2PID instruction. (The numbers (1) to (7) in the diagram indicate the
order of the processing.)
RL, RH
E1
(1)
E2
SV setting
(When used)
CT
RUN (SPA=0)
(6)
Loop stop
determination
SPA
MODE
¸
ERRI DVLI
DVLA
■SV setting processing (1)
The following processing is performed depending on the control mode (MODE) setting.
Control mode (MODE) setting
CAS, CCB, CSV
MAN, AUT, CMV, CMB, CAB, LCM, LCA, LCC
Recommended range
-10 to 110 [%]
DV GW, GG
(2) (3)
Gain (Kp)
Tracking
operation
processing
(7)
Reached
Control cycle
determination
STOP (SPA=1)
(6)
Loop stop
MAN
processing
Processing details
• If the set value (E2) is specified, engineering value transformation processing (refer to the
following expression) is performed, and then "tracking processing (2)" is performed.
RH-RL
SV =
n
100
• If the set value (E2) is not specified, "tracking processing (2)" is performed without
performing engineering value transformation processing.
"Tracking processing (2)" is performed.
Data type
Single-precision
real number
P, D, MTD, CT DVL, DVLS
(4) (5)
Two-degree-
Deviation
of-freedom
check
PID operation
Not reached
BW=0
BW=0
OFF
×E2+RL
11 PROCESS CONTROL INSTRUCTIONS
11.3 Control Operation Instructions
Standard Set by
value
0.0 User
BW
BB1
AND
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