46 lines
1.1 KiB
Plaintext
46 lines
1.1 KiB
Plaintext
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FUNCTION_BLOCK FB_MovingAverage
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VAR_INPUT
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xEnable : BOOL;
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rInput : REAL; // Raw analog value
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iWindowSize : INT := 10; // Number of samples (1..100)
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END_VAR
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VAR_OUTPUT
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rOutput : REAL; // Filtered output
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xReady : BOOL; // TRUE when buffer is full
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END_VAR
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VAR
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arBuffer : ARRAY[0..99] OF REAL; // Circular buffer
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iIndex : INT := 0;
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iCount : INT := 0;
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rSum : REAL := 0.0;
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iWin : INT;
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END_VAR
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IF NOT xEnable THEN
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rOutput := rInput;
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iIndex := 0;
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iCount := 0;
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rSum := 0.0;
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RETURN;
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END_IF;
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// Clamp window size
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iWin := MIN(MAX(iWindowSize, 1), 100);
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// Subtract the oldest value from sum before overwrite
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rSum := rSum - arBuffer[iIndex];
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// Store new value
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arBuffer[iIndex] := rInput;
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rSum := rSum + rInput;
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// Advance circular index
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iIndex := (iIndex + 1) MOD iWin;
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// Track how many samples collected
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IF iCount < iWin THEN
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iCount := iCount + 1;
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END_IF;
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xReady := (iCount >= iWin);
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rOutput := rSum / INT_TO_REAL(iCount); // Valid even before buffer full
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