When you invoke Sonnet software, you start a session. A Sonnet session defines what Sonnet software is presently running, including what modules (tabs) are open, and how the interface tabs are configured. You may only have one session running at a time but there is no limit on the number windows and tabs, nor on the number of open projects. The session manager which appears in every type of Sonnet tab, including the default session tab, allows you to keep track of every tab and project that is open in the present session.
By default, when you open Sonnet, your previous session is automatically loaded. If you wish, you can also save a session in a session file (.sesn) for later use. See File ⇒ Session in the session tab main menu for details. A session file stores the following information:
It is important to understand the distinction between a session and a project. Double-clicking on a project opens a Sonnet session with that project open in an Edit tab, but the project does not store information about the session. The session saves pointers to projects but not the actual project content.
While it is possible to save a session, a session may not be packed. If you wish to send a graph to another user, you should save your plot in a graph file (.sgrx) by selecting the File ⇒ Save command in a Graph tab, then send the packed projects and graph file.
There are two types of projects in Sonnet: the Geometry Project and the Netlist Project. A geometry project contains a circuit whose properties are entered by the user or provided by translating a file to the Sonnet environment. A netlist project contains a circuit defined by a netlist which consists of one or more networks with elements, which can be other geometry projects, connected together.
The most commonly used type of project is the geometry project, and a majority of the documentation concerns the input and analysis of this type of project. The geometry project contains the layout and material properties of a circuit and any internal components. When you analyze a geometry project, em performs an electromagnetic simulation of your circuit.
The Netlist project contains ideal components, data files and Sonnet geometry projects. A network is defined which connects any combination of these items together. A common use for a netlist project is to connect two or more geometry projects together. The analysis engine, em, uses circuit theory to analyze the network.
A project can be opened and used in a session. The follow information is stored in a geometry project file (.son):