As its name suggests, the switch enables you to turn things on or off in a model. Specifically, you can assign a switch to one or more converters in your model, to a sector in your model, or to the sensitivity analysis setup dialog. The switch thus enables you as a model builder to create a friendly device for users to control a model.
When a switch is assigned to a converter, the converter will take on the value of 1 when the switch is on, and 0 when the switch is off. When a switch is assigned to a Sector, Run by sectors for the sector will be turned on when the switch is turned on. Finally, when the switch is assigned to do sensitivity analysis, the current sensi setup will be activated when the switch is turned on. The model will run in normal single-run mode when the switch is turned off.
Whenever you assign a switch to a converter, that converter will be unavailable to connect to other input devices. Switches may only be associated with converters defined as constants. You cannot assign a switch to a stock, a flow or a converter containing equation logic. Finally, a special type of switch, the "chained switch", makes it possible for you to turn "on" one variable while simultaneously turning "off" all other variables in the chain.