The Global ODEs and DAEs (ge) interface (), found under the Mathematics branch () when adding a physics interface, is used to add global space-independent equations that can represent additional degrees of freedom (scalar variables) in a model. The equations can be ODEs, algebraic equations, and DAEs. The main default node is Global Equations, which you use to define the global equations, including the names of the variables, the required initial values, and an optional description.

From the Equation form list, choose Study controlled (the default), Time domain, or Frequency domain. When the setting is Study controlled, the study controls the equation form — stationary or time dependent, for example — for the physics interface. It then appears as Automatic (Stationary), for example, in the Physics and Variables Selection section in the study step’s Settings window. For use in Frequency Domain study steps, and Frequency domain has been selected, select a source for the Frequency to be used when interpreting time derivatives in the equations: From solver (the default) or User defined. When Frequency is User defined, also specify the desired frequency f (SI unit: Hz).

The following nodes are available from the Global ODEs and DAEs ribbon toolbar (Windows users), Global ODEs and DAEs context menu (macOS or Linux users), or by right-clicking to access the context menu (all users).