Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 248

• Deviation for PIDP operation (DV') is calculated as follows.
Condition
DV < -GW
|DV|  GW
DV > GW
DV': Deviation for PIDP operation (%)
DV: Deviation (%)
GW: Gap width (%)
GG: Gap gain
• Deviation (DV) for direct/reverse action is calculated as follows.
Condition
Direct action (PN = 1)
Reverse action (PN = 0)
DV: Deviation (%)
PVP (%): PV input value (%)
100
SV(%)= ×(SV-RL)
RH-RL
RH: Engineering value high limit
RL: Engineering value low limit
SV: Setting value
• PIDP operations are conducted as follows.
Item
Deviation (DVn)
Output variation (MV)
In
Bn
Kp: Gain
Ti: Integral time
Td: Derivative time
Md: Derivative gain
CT: Control cycle
DVn: Deviation
DVn-1: Last deviation value
PVn: Process variable
PVn-1: Last process variable
SVn: Engineering value conversion processing result
10 LOOP CONTROL OPERATION
246
10.11 Position Type PID Control (Enable Tracking for primary loop/Enable Tracking from secondary loop) (M+P_PIDP_EX_T_)
Deviation for PIDP operation (DV')
DV' = -(GG  GW) + (DV + GW)
DV' = GG  DV
DV' = GG  GW + (DV - GW)
Deviation (DV)
DV (%) = PVP (%) - SV (%)
DV (%) = SV (%) - PVP (%)
Direct action
DVn = PVn - SVn
MV = Kp × { DV + I + B }
n n n
Derivative
Integral
Proportional
Gain
CT
I =I + ×DV
n n-1 n
Ti
Md×Td
B =B + ×
n n-1
Md×CT+Td
CT×B
n-1
{(PV -PV )-
n n-1
Td
Reverse action
DVn = SVn - PVn
Md×Td
B =B +
n n-1
Md×CT+Td
{-(PV
}
×
CT×B
n-1
-PV )-
}
n n-1
Td