Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 447

■Variation rate & high/low limiter
This function block checks the variation rate and the high/low limit of each tentative manipulated value for heating and cooling
(T_HT, T_CL) after split conversion.
• Variation rate limiter
Variation rate limiter processing result
DML
DML
Execution cycle (©T)
Variation rate limiter for heating
Condition
|T_HT - MV_HT|  DML_HT
T_HT - MV_HT > DML_HT
T_HT - MV_HT < DML_HT
T_HT: Tentative manipulated value for heating, MV_HT: Heating manipulated variable, DML_HT: Heating output variation rate high limit value
Variation rate limiter for cooling
Condition
|T_CL - MV_CL|  DML_CL
T_CL - MV_CL > DML_CL
T_CL - MV_CL < DML_CL
T_CL: Tentative manipulated value for cooling, MV_CL: Cooling manipulated variable, DML_CL: Cooling output variation rate high limit value
• High/low limiter
High/low limiter processing result
Execution cycle (©T)
Variation rate limiter for heating
Condition
Result of variation rate limiter processing for heating >
MH_HT
Result of variation rate limiter processing for heating <
ML_HT
ML_HT  Result of variation rate limiter processing for
heating  MH_HT
MH_HT: Output high limit value for heating, ML_HT: Output low limit value for heating
Variation rate limiter for cooling
Condition
Result of variation rate limiter processing for cooling >
MH_CL
Result of variation rate limiter processing for cooling <
ML_CL
Tentative MV
(T_HT, T_CL)
DML
DML
DML
Variation rate limiter processing result
T_HT
MV_HT + DML_HT
MV_HT - DML_HT
Variation rate limiter processing result
T_CL
MV_CL + DML_CL
MV_CL - DML_CL
Variation rate limiter processing value
High/low limiter processing
result
MH_HT
ML_HT
Variation rate limiter processing
value for heating
High/low limiter processing
result
MH_CL
ML_CL
Variation rate limiter processing value
Output variation rate
(DML_HT, DML_CL)
DML
DML
t
Alarm (ALM)
Output variation rate limit (DMLA_HT)
FALSE (Reset)
TRUE (Detected)
TRUE (Detected)
Alarm (ALM)
Output variation rate limit (DMLA_HT)
FALSE (Reset)
TRUE (Detected)
TRUE (Detected)
High/low limiter
processing value
Output high limit
(MH_HT, MH_CL)
Output low limit
(ML_HT, ML_CL)
t
Alarm (ALM)
Output low limit alarm
(MLA_HT)
FALSE (Reset)
TRUE (Detected)
FALSE (Reset)
Alarm (ALM)
Output low limit alarm
(MLA_CL)
FALSE (Reset)
TRUE (Detected)
12.40 Heating and Cooling Output (M+M_HTCL_T_)
Output high limit alarm
(MHA_HT)
TRUE (Detected)
FALSE (Reset)
FALSE (Reset)
Output high limit alarm
(MHA_CL)
TRUE (Detected)
FALSE (Reset)
12 LOOP TAG
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