Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 131

Processing details
■Variation rate limiter 2 processing
This function block limits the variation speed to the value input from the input variable IN and outputs the result from the output
variable OUT_.
Input (IN)
Output (OUT_)
Input (IN)
Positive direction limit
(V1LMT)
Negative direction limit
(V2LMT)
When the variation rate of the input (IN) is greater than the limit value, the value of the output (OUT_) is limited as shown
above.
The last value is held if the variation rate limit value is exceeded.
Holding the last value is canceled when the variation rate falls below the limit value.
• Positive direction IN  OUT_
Input (IN-OUT_)
IN - OUT_  V1_  T
IN - OUT_ < V1_  T - HS1
Others
• Negative direction IN < OUT_
Input (IN-OUT_)
OUT_ - IN  V2_  T
OUT_ - IN < V2_  T - HS2
Others
T: Execution cycle
IN: Input value
OUT_: Output value
V1_: Positive direction limit value (/s)
V2_: Negative direction limit value (/s)
HS1: Positive direction hysteresis
HS2: Negative direction hysteresis
When HS1 is less than 0 or HS2 is less than 0, an operation error occurs.
Condition
HS1  0 and HS2  0
HS1  0 and HS2 < 0
HS1 < 0 and HS2  0
HS1 < 0 and HS2 < 0
When positive direction limit value is over,
output (OUT_) holds the previous value.
When negative direction limit value is over,
output (OUT_) holds the previous value.
Output (OUT_)
TRUE (Negative direction limit occurs)
TRUE (Positive direction limit occurs)
Output (OUT_)
OUT_ = OUT_
OUT_ = IN
OUT_ = OUT_
Output (OUT_)
OUT_ = OUT_
OUT_ = IN
OUT_ = OUT_
t
t
t
Positive direction limit
(V1LMT)
TRUE (Detected)
FALSE (Canceled)
Last value
Positive direction limit
(V1LMT)
FALSE (Canceled)
FALSE (Canceled)
Last value
Result
Normal
Operation error
Operation error
Operation error
8.7 Variation Rate Limiter 2 (M+P_VLMT2)
Negative direction limit
(V2LMT)
FALSE (Canceled)
FALSE (Canceled)
Last value
Negative direction limit
(V2LMT)
TRUE (Detected)
FALSE (Canceled)
Last value
8 CONTROL OPERATION
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