Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 153

Processing details
■Input addition
A tentative manipulated value (T) is calculated from the input value (MV).
(MV is output from an FB (such as M+P_PID) before this FB every control cycle (CT).)
ΔMV input (MVD)
ΔMV1
MVP=T
ΔMV1
Execution cycle (ΔT)
Control cycle (CT)
T = MV + MVP
MVP = T
MV: Input value to input (MVD), MVP: MV internal operation value, T: Tentative manipulated value
• When the control mode is switched from MAN or CMV to AUT or CSV, a manipulated value (MV) is stored in the MV
internal operation value (MVP) to avoid sudden changes of the manipulated value at switching.
• During data tacking, MV is 0 and the manipulated value (MV) is stored in the MV internal operation value (MVP).
■Variation rate & high/low limiter
This function block checks the variation rate and high/low limits of the input value.
• Variation rate limiter
Variation rate limiter processing result
DML
DML
Execution cycle (ΔT)
Control cycle (CT)
Condition
|T - MV|  DML
T - MV > DML
T - MV < -DML
T: Tentative manipulated value, MV: Manipulated value, DML: Output variation rate high limit value
ΔMV2
ΔMV2
Control cycle (CT)
Tentative MV value (T)
DML
DML
Control cycle (CT)
Variation rate limiter processing result
T
MV + DML
MV - DML
9.2 Output Processing-1 with Mode Switching (With Input Addition) (M+P_OUT1)
ΔMV3
t
ΔMV3
t
Control cycle (CT)
Variation rate limiter
processing value
DML
DML
DML
t
Control cycle (CT)
Alarm (ALM)
Output variation rate limit (DMLA)
FALSE (Reset)
TRUE (Detected)
TRUE (Detected)
9
9 I/O CONTROL
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