RootMeanSquare

```block RootMeanSquare "Calculate root mean square over period 1/f"
extends Modelica.Blocks.Interfaces.SISO;

parameter Modelica.SIunits.Frequency f(start = 50) "Base frequency";
parameter Real x0 = 0 "Start value of integrator state";
MultiProduct product(nu = 2) annotation (Placement(transformation(extent = {
{-40, -10},
{-20, 10}})));
Mean mean(final f = f, final yGreaterOrEqualZero = true, final x0 = x0) annotation (Placement(transformation(extent = {
{0, -10},
{20, 10}})));
Blocks.Math.Sqrt sqrt1 annotation (Placement(transformation(extent = {
{40, -10},
{60, 10}})));
equation
connect(u,product.u[1]) annotation (Line(
points = {
{-120, 0},
{-60, 0},
{-60, 3.5},
{-40, 3.5}},
color = {0, 0, 127}));
connect(u,product.u[2]) annotation (Line(
points = {
{-120, 0},
{-60, 0},
{-60, -3.5},
{-40, -3.5}},
color = {0, 0, 127}));
connect(mean.y,sqrt1.u) annotation (Line(
points = {
{21, 0},
{38, 0}},
color = {0, 0, 127}));
connect(product.y,mean.u) annotation (Line(
points = {
{-18.3, 0},
{-2, 0}},
color = {0, 0, 127}));
connect(sqrt1.y,y) annotation (Line(
points = {
{61, 0},
{110, 0}},
color = {0, 0, 127}));

annotation (
Documentation(info = "<html>\n<p>\nThis block calculates the root mean square of the input signal u over the given period 1/f, using the\n<a href=\"modelica://Modelica.Blocks.Math.Mean\">mean block</a>.\n</p>\n<p>\nNote: The output is updated after each period defined by 1/f.\n</p>\n</html>"),
Icon(graphics = {
Text(
extent = {
{-80, 60},
{80, 20}},
textString = "RMS"),
Text(
extent = {
{-80, -20},
{80, -60}},
textString = "f=%f")}));
end RootMeanSquare;

```