Table of Contents

Equithermal Curve - Using Four Points

Full Name

Lib.Mervis.v1_0.EquithermalCurve4Point

Required Project References

Description

A block for calculating the heating medium temperature according to an equithermal curve defined by four points.

Usage in ST

program test
    var
        eq4p: lib.mervis.v1_0.EquithermalCurve4Point;
    end_var

    eq4p();
end_program

Inputs

Name Data TypeRetainMandatory ConnectionMeaning
In real No Yes Outdoor temperature
X1 real Yes No First point of the curve - outdoor temperature
Y1 real Yes No First point of the curve - heating medium temperature
X2 real Yes No Second point of the curve - outdoor temperature
Y2 real Yes No Second point of the curve - heating medium temperature
X3 real Yes No Third point of the curve - outdoor temperature
Y3 real Yes No Third point of the curve - heating medium temperature
X4 real Yes No Fourth point of the curve - outdoor temperature
Y4 real Yes No Fourth point of the curve - heating medium temperature
DY real Yes No Offset for the heating medium temperature

Outputs

Name Data TypeMeaning
Out real Calculated heating medium temperature

Detailed Function Description

The block calculates the heating medium temperature based on the outdoor temperature. The equithermal curve is defined by four points, with the condition that X1 < X2 < X3 < X4 must be satisfied for proper operation.