Mitsubishi MELSEC-Q series Programming Manual page 114

S.PIDP
(4) PID operation
PID operation is performed with the following operation expression.
Item
When forward operation
(PN = 1)
Bn
When reverse operation
(PN = 0)
In
T
K : K × Gain (P), M : Derivative gain (MTD)
P D
T : Integral constant (I), T
I
In the following case, however, note that special processing will be performed.
QnPHCPU (First 5 digits of the serial No.
: 07031 or earlier)
In either of the following cases 1, 2
1. Derivative constant (D) = 0 (T
2. Operation mode (MODE) is any of MAN, LCM and CMV
In any of the following cases 1, 2, 3
1. Integral constant (I) = 0 (T
2. When MHA is turned to 1
CT
DV 0
n
T
I
3. When MLA is turned to 1
CT
DV 0
n
T
I
––
(5) Deviation check
A deviation check is made under the following condition and the result of the check is output to DVLA of the alarm
detection (ALM) and the deviation large alarm (BB2) of the block memory.
Condition
DVL < |DV|
(DVL - DVLS) < |DV|  DVL
|DV|  (DVL - DVLS)
*1 When DVLI or ERRI in the alarm detection inhibition (INH) is set to 1, DVLA and BB2 show 0 since the alarm is prohibited.
112
B
n-1
B
n-1
I
n-1
Kp×(DVn + In + Bn)
: Derivative constant (D)
D
Condition
QnPHCPU (First 5 digits of the serial No.
: 07032 or later)
= 0)
D
In any of the following cases 1, 2, 3, 4
1. Integral constant (I) = 0 (T
= 0) 2. When MHA2 is turned to 1
I
CT
DV 0
n
T
I
3. When MLA2 is turned to 1
CT
DV 0
n
T
I
4. When operating mode (MODE) is any of MAN, LCM, and
CMV.
All the following conditions 1, 2, 3 are satisfied
1. When b0 of SD1508 is turned to 1
2. When tracking flag (TRKF) in alarm detection inhibition (INH)
is turned to 1.
3. When operating mode (MODE) is other than MAN, LCM, and
CMV.
Operation expression
M T
D D
{(PV PV )
n n-1
M CT T
D D
M T
D D
{ (PV PV )
n n-1
M CT T
D D
CT
DV
n
T
I
QnUDPVCPU
= 0)
I
Result
*1
DVLA=BB2=1
DVLA=BB2=Last value status hold
DVLA=BB2=0
CT B
n-1
}
T
D
CT B
n-1
}
T
D
Processing
B = 0
n
(However, the loop tag
past value memory is
set.)
CT
DV 0
n
T
I
MV
I - (DV
n-1 =
K
p
TRKF=0
*1
B )
n + n