Right-click a Device Model or Device Model Feature node and choose Device Equations () from the Devices submenu.

To add a Device Equations node to a physics feature or physics property node, right-click the node and choose Device from the Devices submenu. If added under any of these nodes or a Component node, the device equations node belongs to the device models closest in the hierarchy. For most cases this will be the device model added by the physics interface.

Fill in the table with Left-hand side and Right-hand side of an arbitrary number of Device Equations. You can use any device variable, device input, or device constant in these equations. If you want to use nondevice variables, add a scope specifier to the variable.

Assume for example that you want to use the variable A declared by a variable declaration in a device equation. In an ordinary expression you just type A, but in a device equation, the parser assumes that this is a device variable named A. Instead you type phys.A to specify that this is a variable outside the device context.

For valid entries in the Dimension column, see Variable Declaration.