Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 242

■Engineering value conversion
This function block converts the setting value (%) from the primary loop in the CAS or CSV mode into an engineering value.
RH-RL
× Setting value (%) from the primary loop + RL
SV=
100
RH: Engineering value high limit, RL: Engineering value low limit, SV: Setting value
■Inverse engineering value conversion
This function block converts the setting value (SV) of an engineering value into a setting value (SV) in percentage (%).
100
SV(%)= ×(SV-RL)
RH-RL
RH: Engineering value high limit, RL: Engineering value low limit, SV: Setting value
■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
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
• High/low limiter
High/low limiter processing result
Execution cycle (ΔT)
Control cycle (CT)
Condition
Variation rate limiter processing result
> MH
Variation rate limiter processing result
< ML
ML  Variation rate limiter processing
result  MH
MH: Output high limit value, ML: Output low limit value
10 LOOP CONTROL OPERATION
240
10.10 Position Type PID Control (Disable Tracking for primary loop/Disable Tracking from secondary loop) (M+P_PIDP)
Tentative MV value (T)
DML
DML
Control cycle (CT)
Variation rate limiter processing result
T
MV + DML
MV - DML
Variation rate limiter processing value
Control cycle (CT)
High/low limiter processing
result
MH
ML
Variation rate limiter processing value
DML
DML
Control cycle (CT)
Control cycle (CT)
Alarm (ALM)
Output Low Limit Alarm (MLA)
FALSE (Reset)
TRUE (Detected)
FALSE (Reset)
Variation rate limiter
processing value
DML
DML
t
Alarm (ALM)
Output variation rate limit (DMLA)
FALSE (Reset)
TRUE (Detected)
TRUE (Detected)
High/low limiter
processing value
Output high limit
(MH)
Output low limit
(ML)
t
Output High Limit Alarm
(MHA)
TRUE (Detected)
FALSE (Reset)
FALSE (Reset)