From 39765e002e71a2dd54e932469877acfc1b6fcb67 Mon Sep 17 00:00:00 2001
From: pux <pux@pux.dom>
Date: Thu, 7 Jan 2021 19:39:17 +0100
Subject: add *.exp; (this is redundant information, just to be able to diff
 later on)

---
 exp/FB_EWMA.EXP | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 exp/FB_EWMA.EXP

(limited to 'exp/FB_EWMA.EXP')

diff --git a/exp/FB_EWMA.EXP b/exp/FB_EWMA.EXP
new file mode 100644
index 0000000..6496df9
--- /dev/null
+++ b/exp/FB_EWMA.EXP
@@ -0,0 +1,35 @@
+
+(* @NESTEDCOMMENTS := 'Yes' *)
+(* @PATH := '' *)
+(* @OBJECTFLAGS := '0, 8' *)
+(* @SYMFILEFLAGS := '2048' *)
+FUNCTION_BLOCK FB_EWMA
+VAR_INPUT
+	IN_rN			: REAL := 15;	(* Filter constant alpha := rN/(rN+1) *)
+	IN_rXk			: REAL;			(* Input value to smooth *)
+END_VAR
+VAR_OUTPUT
+	OUT_rXk_avg		: REAL;		(* smoothed output *)
+END_VAR
+VAR
+	rAlpha			: REAL;
+	rXk_avg_old		: REAL;
+END_VAR
+
+(* Exponentially Weighted Moving Average Filter
+Author: mo
+Date: 2019-02
+
+Filter constant:	alpha := n / (n+1)
+EWMA Filter:		Xk_avg := alpha*Xk_prev + (1-alpha)*Xk
+
+*)
+(* @END_DECLARATION := '0' *)
+rAlpha := IN_rN/(IN_rN+1);
+
+OUT_rXk_avg :=	rAlpha * rXk_avg_old
+			+ ( (1 - rAlpha) * IN_rXk);
+
+rXk_avg_old := OUT_rXk_avg;
+
+END_FUNCTION_BLOCK
-- 
cgit v1.2.2-1-g5e49