A step can perform many actions, such as initializing an instrument, performing a complex test, or controlling the flow of execution in a sequence. Steps perform these actions through several types of mechanisms, including jumping to another step, executing an expression, calling a subsequence, or calling an external code module.

Steps can include built-in and custom properties. For steps that call code modules, the module adapter uses the built-in step properties to store parameters to pass to the code module and to specify where to store results the code module returns.

Not all steps call code modules. Some steps perform standard actions you configure using panes and dialog boxes. In this case, the panes and dialog boxes use the custom step properties to store the configuration settings you specify.