Control system of a technical installation, which has at least one operator station server and one operator station client, which operator station server has a visualisation service for outputting image information to the operator station client, and in which operator station server at least two object models of technical objects of the technical installation are stored, which technical objects underlie the object models, and wherein the operator station server is embodied to generate an XY trend diagram with an operating point (A1, A2, A3, A4) visualised in the XY trend diagram from a first measurement value associated with the first technical object and a second measurement value associated with the second technical object, and is embodied to transmit the XY trend diagram with the operating point (A1, A2, A3, A4) to the operator station client by means of the visualisation service, characterised in that the XY trend diagram and/or the operating point (A1, A2, A3, A4) has a reference to at least one of the object models, wherein the operating point (A1, A2, A3, A4) can be influenced by the technical object underlying the referenced object model, and that an operator of the operator station client is visually presented with the at least one referenced object model by means of the visualisation service when selecting the operating point (A1, A2, A3, A4) in the XY trend diagram, wherein the operator of the operator station client, in the event that he performs a graphical shifting of the operating point (A1, A2, A3, A4) in an X- or Y-direction within the XY trend diagram, is only visually presented with the object model of an underlying technical object, which object model brings about a shifting of the operating point (A1, A2, A3, A4) in the specific X- or Y-direction. which operator station server has a visualisation service for outputting image information to the operator station client, and in which operator station server at least two object models of technical objects of the technical installation are stored, which technical objects underlie the object models, and wherein the operator station server is embodied to generate an XY trend diagram with an operating point (A1, A2, A3, A4) visualised in the XY trend diagram from a first measurement value associated with the first technical object and a second measurement value associated with the second technical object, and is embodied to transmit the XY trend diagram with the operating point (A1, A2, A3, A4) to the operator station client by means of the visualisation service, characterised in that the XY trend diagram and/or the operating point (A1, A2, A3, A4) has a reference to at least one of the object models, wherein the operating point (A1, A2, A3, A4) can be influenced by the technical object underlying the referenced object model, and that an operator of the operator station client is visually presented with the at least one referenced object model by means of the visualisation service when selecting the operating point (A1, A2, A3, A4) in the XY trend diagram, wherein the operator of the operator station client, in the event that he performs a graphical shifting of the operating point (A1, A2, A3, A4) in an X- or Y-direction within the XY trend diagram, is only visually presented with the object model of an underlying technical object, which object model brings about a shifting of the operating point (A1, A2, A3, A4) in the specific X- or Y-direction.