1. A method for configuring a test device set up for testing an electronic control unit via a configuration system, the method comprising: executing a software model of a technical system in the test device, the software model communicating via an input/output interface of the test device with a device connected to the test device, the configuration system having a first configuration element of a first type and a second configuration element of a second type, assigning properties of the test device to the first configuration element and the second configuration element, a communication between the connected device and the software model being configured with the properties; sorting the properties in the configuration system, the sorting being switchable between sorting types, the sorting types including a union set sort, an intersection sort, and a condensing sort; and sorting the properties of the union set sort resulting in the properties assigned to the first configuration element generating a first joined set that contains only the properties assigned to the first configuration element, and the properties assigned to the second element generating a second joined set that contains only the properties assigned to the second configuration element, wherein the intersection sort sorts the properties resulting in a third joined set of the properties whose assigned configuration elements are of a same type, wherein the condensing sort occurs resulting in a fourth joined set of the properties that are included in both the first configuration element and second configuration element, wherein the test device is configured by compiling program code generated with the configuration environment based on the properties of the first configuration element and the second configuration element, and wherein the first configuration element and the second configuration element have ports, and connections between the ports of the first configuration element and the second configuration element are automatically assigned to enable electronic communication.