A method for constituting a reference data structure (DR) comprising at least one setpoint parameter (PAR) of at least one actuator of an equipment of a building automation installation, comprising: - a step (S10) of determining a set (E1) of at least one combination (CVE1) of values (VE1) of quantities measurable by at least one sensor associated to the actuator , called set of functional data (E1); - a step (S20) of determining, for at least one determined combination (CVE1j) belonging to the set of functional data (E1), at least one value (VPi) corresponding to the at least one setpoint parameter (PAR), as a function of the determined combination (CVE1j); - a step (S30) of generating the reference data structure (DR) comprising a set of association ({CVE1j; VPi}) between the at least one determined value (VPi) corresponding to the at least one setpoint parameter and the determined combination (CVE1j) belonging to the set (E1) of functional data (CVE1), characterized in that the generation step (S30) comprises a sub-step (S35) of digitally encoding the reference data structure (DR) in the form of an image (I) comprising a set of pixels (Px), each pixel (Px) of the image being defined by a positioning and at least one component, - the positioning (Pos) of a pixel (Px) in the image (I) being determined as a function (f) of the values (VE1) of the measurable quantities in said different combinations (CVE1) of the set of functional data (E1), and - the at least one component of a pixel (Px) of the at least one image (I) corresponding to the setpoint parameter values (PAR) for a determined combination (CVE1) of values (VE1) of the measurable quantities of the set of functional data (E1). - a step (S10) of determining a set (E1) of at least one combination (CVE1) of values (VE1) of quantities measurable by at least one sensor associated to the actuator , called set of functional data (E1); - a step (S20) of determining, for at least one determined combination (CVE1j) belonging to the set of functional data (E1), at least one value (VPi) corresponding to the at least one setpoint parameter (PAR), as a function of the determined combination (CVE1j); - a step (S30) of generating the reference data structure (DR) comprising a set of association ({CVE1j; VPi}) between the at least one determined value (VPi) corresponding to the at least one setpoint parameter and the determined combination (CVE1j) belonging to the set (E1) of functional data (CVE1), characterized in that the generation step (S30) comprises a sub-step (S35) of digitally encoding the reference data structure (DR) in the form of an image (I) comprising a set of pixels (Px), each pixel (Px) of the image being defined by a positioning and at least one component, - the positioning (Pos) of a pixel (Px) in the image (I) being determined as a function (f) of the values (VE1) of the measurable quantities in said different combinations (CVE1) of the set of functional data (E1), and - the at least one component of a pixel (Px) of the at least one image (I) corresponding to the setpoint parameter values (PAR) for a determined combination (CVE1) of values (VE1) of the measurable quantities of the set of functional data (E1). <EOS>