Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 179

Processing details
■High limit check
This function block performs the high limit check to the input (CIN).
Condition
CIN > PH_
Others
CIN: Count value, PH_: PV high limit alarm value
■Variation rate check
During the variation rate alarm check time (CTIM), this function block compares input changes with the variation rate alarm
value (DPL) every execution cycle T and checks variation rate alarms.
DPL
Xn
a
ΔT
Input
In the example above, the variation rate b, c, d, e relative to Xn is checked and alarm output is exported.
b: Xn+1-Xn
c: Xn+2-Xn (DPPA occurrence)
d: Xn+3-Xn (DPPA occurrence)
e: Xn+4-Xn (DPPA occurrence)
Condition
(Xn + m) - Xn  DPL
Others
DPL: Variation rate alarm value (%)
m: Variation rate monitoring counter
CTIM
m=
ΔT
T: Execution cycle
CTIM: Variation rate alarm check time
DPL
Xn+2
Xn+4
Xn+3
Xn+1
b c
d e
CTIM
DPPA
Alarm (ALM)
Input high limit (PHA)
TRUE (Detected)
FALSE (Reset)
Xn
CTIM
Alarm (ALM)
Positive variation rate (DPPA)
TRUE (Detected)
FALSE (Reset)
9 I/O CONTROL
9.8 Batch Counter (M+P_BC)
9
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