37 lines
890 B
Plaintext
37 lines
890 B
Plaintext
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#Limits how fast the signal can change per scan cycle — useful for preventing actuator shock.
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FUNCTION_BLOCK FB_RateLimiter
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VAR_INPUT
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xEnable : BOOL;
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rInput : REAL;
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rMaxRiseRate : REAL := 10.0; // Max units per second rising
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rMaxFallRate : REAL := 10.0; // Max units per second falling
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rCycleTimeS : REAL := 0.1; // OB cycle time in seconds
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END_VAR
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VAR_OUTPUT
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rOutput : REAL;
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END_VAR
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VAR
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xFirst : BOOL := TRUE;
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rMaxStep : REAL;
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rMinStep : REAL;
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rDelta : REAL;
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END_VAR
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IF NOT xEnable THEN
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xFirst := TRUE;
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rOutput := rInput;
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RETURN;
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END_IF;
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IF xFirst THEN
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rOutput := rInput;
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xFirst := FALSE;
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RETURN;
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END_IF;
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rMaxStep := rMaxRiseRate * rCycleTimeS;
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rMinStep := -rMaxFallRate * rCycleTimeS;
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rDelta := rInput - rOutput;
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rDelta := MAX(MIN(rDelta, rMaxStep), rMinStep);
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rOutput := rOutput + rDelta;
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